Immunomodulatory and Anti-inflammatory effect of Neural Stem/Progenitor Cells in the Central Nervous System

DON-Apt19S bioactive scaffold transplantation promotes in situ spinal cord repair in rats with transected spinal cord injury by effectively recruiting endogenous neural stem cells and mesenchymal stem cells

The spinal cord's limited regeneration is attributed to the scarcity of endogenous stem cells and a poor post-injury microenvironment in adult mammals. To overcome these challenges, we transplanted a DNA aptamer 19S (Apt19S) sustained-release decellularized optic nerve (DON) scaffold (DON-A) into completely transected spinal cord injury (SCI) site in rats and investigated its effect on endogenous stem cell recruitment and differentiation, which subsequently contributed to in situ SCI repair. It has been demonstrated that Apt19S specifically binds to the membrane receptor alkaline phosphatase highly expressed on neural stem cells (NSCs) and mesenchymal stem cells (MSCs), and our study further proved that Apt19S can simultaneously recruit endogenous NSCs and MSCs to the lesion of SCI. In our study, the DON-A promoted stem cell proliferation in the early stage of the injury, followed by the rapid neurogenesis through NSCs and revascularization via MSCs. Synaptic connections between corticospinal tracts and calcitonin gene-related peptide positive nerve fibers with newborn neurons confirmed the formation of endogenous neuronal relays at the injury site, which improved the rats' motor and sensory functions. This study offers a new strategy for recruiting both NSCs and MSCs to synergistically overcome low spinal cord self-repair ability, holding a high potential for clinical translation.

Congenital CMV infection and central nervous system involvement: mechanisms, treatment, and long-term outcomes

Congenital Cytomegalovirus (cCMV) infection is the leading infectious cause of non-genetic sensorineural hearing loss and a significant cause of neurodevelopmental disability in infants. This narrative review aims to describe the mechanisms by which CMV disrupts fetal brain development in early gestation, the importance of neonatal neuroimaging in predicting prognosis, and the optimal intervention for preventing neurologic sequelae. We performed a literature search on PUBMED on this topic and selected the most relevant results, including studies describing neurologic outcomes, neuroimaging, hearing loss, treatment efficacy, or follow-up recommendations in infants with cCMV, prioritizing randomized controlled trials (RCTs), systematic reviews, and expert consensus guidelines. The pathogenesis of cCMV infection is the result of various mechanisms that the virus uses to replicate in the developing fetal central nervous system; the major cause of structural damage to the brain is aberrant migration of neuronal precursors. Recent literature stresses the importance of neuroimaging and the role of neuroradiologic scores to predict neurologic sequelae. The management of infants with isolated SNHL, especially those diagnosed after the neonatal period, remains controversial, though emerging evidence suggests a potential therapeutic window up to 12 weeks of age. Follow-up protocols should be tailored based on clinical presentation, with close audiologic and developmental surveillance.

CONCLUSIONS

Despite recent advances, key knowledge gaps persist regarding the mechanisms of CNS injury, optimal screening for vestibular dysfunction, neonatal biomarkers of prognosis, and treatment indications for isolated SNHL. Targeted research and standardized follow-up models are essential to improve outcomes in this vulnerable population.

WHAT IS KNOWN

• Congenital Cytomegalovirus infection is the leading infectious cause of non-genetic sensorineural hearing loss and a significant cause of neurodevelopmental disability in infants. • Neurological complications remain the most significant contributors to morbidity in cCMV infection.

WHAT IS NEW

• Beyond classical neurological manifestations, cCMV infected babies show a high prevalence of vestibular dysfunction; neurodevelopmental sequelae are frequent, including autism, attention deficit, and learning difficulties, and may occur even in asymptomatic cases. Neuroradiologic scoring systems proved to be predictive of developmental outcomes. • This review proposes a structured follow-up model tailored to clinical and imaging findings and discusses prognostic factors that may help identify children at increased risk for late-onset sequelae.

Neural stem cell-derived small extracellular vesicles: a new therapy approach in neurological diseases

Neural stem cells (NSCs) possess pluripotent characteristics, proliferative capacity, and the ability to self-renew. In the context of neurological diseases, transplantation of NSCs has been shown to facilitate neurological repair through paracrine mechanisms. NSC-derived small extracellular vesicles (NSC-sEVs), a prominent component of the NSC secretome, play a crucial role in modulating various physiological and pathological processes, such as regulating the NSC microenvironment, promoting endogenous NSC differentiation, and facilitating the maturation of neurons and glial cells. Moreover, NSC-sEVs exhibit reduced immunogenicity, decreased tumorigenic potential, and enhanced ability to traverse the blood-brain barrier. Consequently, NSC-sEVs present novel therapeutic approaches as non-cellular treatments for neurological disorders and are poised to serve as a viable alternative to stem cell therapies. Furthermore, NSC-sEVs can be manipulated to enhance production efficiency, improve biological activity, and optimize targeting specificity, thereby significantly advancing the utilization of NSC-sEVs in clinical settings for neurological conditions. This review provides a comprehensive overview of the biological functions of NSC-sEVs, their therapeutic implications and underlying molecular mechanisms in diverse neurological disorders, as well as the potential for engineering NSC-sEVs as drug delivery platforms. Additionally, the limitations and challenges faced by NSC-sEVs in practical applications were discussed in depth, and targeted solutions were proposed.

Immune Cell-NSPC interactions: Friend or foe in CNS injury and repair?

Neural stem/progenitor cells (NSPCs) play a crucial role in central nervous system (CNS) development, regeneration, and repair. However, their functionality and therapeutic potential are intricately modulated by interactions with immune cells, particularly macrophages and microglia. Microglia, as CNS-resident macrophages, are distinct from peripheral macrophages in their roles and characteristics, contributing to specialized functions within the CNS. Recent evidence suggests that microglia, as CNS-resident macrophages, contribute to the quality assurance of NSPCs by eliminating stressed or dysfunctional cells, yet the mechanisms underlying this process remain largely unexplored. Furthermore, macrophage polarization states, such as M1 and M2, appear to differentially influence NSPC quality, potentially impacting neurogenesis and regenerative outcomes. Identifying surface markers indicative of NSPC stress could provide a strategy for selecting optimal cells for transplantation therapies. Additionally, in vivo clonal labeling approaches may enable precise tracking of NSPC fate and their interactions with immune cells. Beyond macrophages and microglia, the roles of other immune cells, including T cells and neutrophils, particularly in injury and neurodegenerative disease contexts, in the context of CNS injury and disease are emerging areas of interest. Here, I discuss the emerging evidence supporting the interplay between the immune system and NSPCs, highlighting critical gaps in knowledge and proposing future research directions to harness immune-mediated mechanisms for optimizing neural regeneration and transplantation strategies.

Neurological and immunological characteristics of a novel immortalized bovine brainstem-derived cell line and its susceptibility to arbovirus infection

Immortalized bovine neuronal cell lines provide a reliable in vitro model for studying interactions with bovine infectious pathogens that target the host nervous system. Although we previously established an immortalized fetal bovine brain-derived FBBC-1 cell line, there are currently no other bovine neuronal cell lines commonly available. In the present study, we developed a novel immortalized cell line, IKBM, derived from the adult bovine brainstem by transferring a SV40 large T antigen gene using lentiviral vectors, and compared its characteristics to the FBBC-1 cell line. As with FBBC-1 cells, IKBM cells extended neurite-like processes in response to agents that increase cytosolic cyclic AMP levels. A comprehensive analysis using RNA sequencing demonstrated that both cell lines potentially possess neural progenitor cell-like properties and differentiate into dopaminergic neuron-like cells after induction of the outgrowth of neurite-like processes. Unexpectedly, we found that the mRNAs of multiple immunomodulatory molecules were highly expressed in IKBM cells, but not in FBBC-1 cells. Although IKBM cells were susceptible to infection with arboviruses (Akabane and Chuzan viruses) that cause neurological symptoms in cattle, viral titers were lower in IKBM cell cultures than in hamster lung-derived HmLu-1 cell cultures, which are frequently used to isolate arboviruses. The reduced production of viruses in IKBM cell cultures may be related to the high expression of immunomodulatory molecules in these cells. Therefore, IKBM and FBBC-1 cell lines offer the opportunity to develop unique in vitro models of the bovine nervous system for the study of host-pathogen interactions based on their respective properties.

Emerging strategies for nerve repair and regeneration in ischemic stroke: neural stem cell therapy

Ischemic stroke is a major cause of mortality and disability worldwide, with limited treatment options available in clinical practice. The emergence of stem cell therapy has provided new hope to the field of stroke treatment via the restoration of brain neuron function. Exogenous neural stem cells are beneficial not only in cell replacement but also through the bystander effect. Neural stem cells regulate multiple physiological responses, including nerve repair, endogenous regeneration, immune function, and blood-brain barrier permeability, through the secretion of bioactive substances, including extracellular vesicles/exosomes. However, due to the complex microenvironment of ischemic cerebrovascular events and the low survival rate of neural stem cells following transplantation, limitations in the treatment effect remain unresolved. In this paper, we provide a detailed summary of the potential mechanisms of neural stem cell therapy for the treatment of ischemic stroke, review current neural stem cell therapeutic strategies and clinical trial results, and summarize the latest advancements in neural stem cell engineering to improve the survival rate of neural stem cells. We hope that this review could help provide insight into the therapeutic potential of neural stem cells and guide future scientific endeavors on neural stem cells.

The role of astrocyte in neuroinflammation in traumatic brain injury

Traumatic brain injury (TBI), a significant contributor to mortality and morbidity worldwide, is a devastating condition characterized by initial mechanical damage followed by subsequent biochemical processes, including neuroinflammation. Astrocytes, the predominant glial cells in the central nervous system, play a vital role in maintaining brain homeostasis and supporting neuronal function. Nevertheless, in response to TBI, astrocytes undergo substantial phenotypic alternations and actively contribute to the neuroinflammatory response. This article explores the multifaceted involvement of astrocytes in neuroinflammation subsequent to TBI, with a particular emphasis on their activation, release of inflammatory mediators, modulation of the blood-brain barrier, and interactions with other immune cells. A comprehensive understanding the dynamic interplay between astrocytes and neuroinflammation in the condition of TBI can provide valuable insights into the development of innovative therapeutic approaches aimed at mitigating secondary damage and fostering neuroregeneration.

Advancing Spinal Cord Injury Treatment through Stem Cell Therapy: A Comprehensive Review of Cell Types, Challenges, and Emerging Technologies in Regenerative Medicine

Spinal cord injuries (SCIs) can lead to significant neurological deficits and lifelong disability, with far-reaching physical, psychological, and economic consequences for affected individuals and their families. Current treatments for SCIs are limited in their ability to restore function, and there is a pressing need for innovative therapeutic approaches. Stem cell therapy has emerged as a promising strategy to promote the regeneration and repair of damaged neural tissue following SCIs. This review article comprehensively discusses the potential of different stem cell types, such as embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), mesenchymal stem cells (MSCs), and neural stem/progenitor cells (NSPCs), in SCI treatment. We provide an in-depth analysis of the unique advantages and challenges associated with each stem cell type, as well as the latest advancements in the field. Furthermore, we address the critical challenges faced in stem cell therapy for SCIs, including safety concerns, ethical considerations, standardization of protocols, optimization of transplantation parameters, and the development of effective outcome measures. We also discuss the integration of novel technologies such as gene editing, biomaterials, and tissue engineering to enhance the therapeutic potential of stem cells. The article concludes by emphasizing the importance of collaborative efforts among various stakeholders in the scientific community, including researchers, clinicians, bioengineers, industry partners, and patients, to overcome these challenges and realize the full potential of stem cell therapy for SCI patients. By fostering such collaborations and advancing our understanding of stem cell biology and regenerative medicine, we can pave the way for the development of groundbreaking therapies that improve the lives of those affected by SCIs.

Neural stem cell-derived extracellular vesicles: mini players with key roles in neurogenesis, immunomodulation, neuroprotection and aging

Neural stem/progenitor cells (NSPCs) are self-renewing and multipotent cells of the central nervous system where they give rise to neurons, astrocytes and oligodendrocytes both during embryogenesis and throughout adulthood, although only in a few discrete niches. NSPC can integrate and send a plethora of signals not only within the local microenvironment but also at distance, including the systemic macroenvironment. Extracellular vesicles (EVs) are currently envisioned as main players in cell-cell communication in basic and translational neuroscience where they are emerging as an acellular alternative in regenerative medicine. At present NSPC-derived EVs represent a largely unexplored area compared to EVs from other neural sources and EVs from other stem cells, i.e., mesenchymal stem cells. On the other hand, available data suggest that NSPC-derived EVs can play key roles on neurodevelopmental and adult neurogenesis, and they are endowed with neuroprotective and immunomodulatory properties, and even endocrine functions. In this review we specifically highlight major neurogenic and "non-neurogenic" properties of NSPC-EVs, the current knowledge on their peculiar cargos and their potential translational value.