Myelin repair in vivo is increased by targeting oligodendrocyte precursor cells with nanoparticles encapsulating leukaemia inhibitory factor (LIF)

The role of myelin in neurodegeneration: implications for drug targets and neuroprotection strategies

Myelination of axons in the central nervous system offers numerous advantages, including decreased energy expenditure for signal transmission and enhanced signal speed. The myelin sheaths surrounding an axon consist of a multi-layered membrane that is formed by oligodendrocytes, while specific glycoproteins and lipids play various roles in this formation process. As beneficial as myelin can be, its dysregulation and degeneration can prove detrimental. Inflammation, oxidative stress, and changes in cellular metabolism and the extracellular matrix can lead to demyelination of these axons. These factors are hallmark characteristics of certain demyelinating diseases including multiple sclerosis. The effects of demyelination are also implicated in primary degeneration in diseases such as glaucoma and Alzheimer's disease, as well as in processes of secondary degeneration. This reveals a relationship between myelin and secondary processes of neurodegeneration, including resultant degeneration following traumatic injury and transsynaptic degeneration. The role of myelin in primary and secondary degeneration is also of interest in the exploration of strategies and targets for remyelination, including the use of anti-inflammatory molecules or nanoparticles to deliver drugs. Although the use of these methods in animal models of diseases have shown to be effective in promoting remyelination, very few clinical trials in patients have met primary end points. This may be due to shortcomings or considerations that are not met while designing a clinical trial that targets remyelination. Potential solutions include diversifying disease targets and requiring concomitant interventions to promote rehabilitation.

Key roles of glial cells in the encephalopathy of prematurity

Across the globe, approximately one in 10 babies are born preterm, that is, before 37 weeks of a typical 40 weeks of gestation. Up to 50% of preterm born infants develop brain injury, encephalopathy of prematurity (EoP), that substantially increases their risk for developing lifelong defects in motor skills and domains of learning, memory, emotional regulation, and cognition. We are still severely limited in our abilities to prevent or predict preterm birth. No longer just the "support cells," we now clearly understand that during development glia are key for building a healthy brain. Glial dysfunction is a hallmark of EoP, notably, microgliosis, astrogliosis, and oligodendrocyte injury. Our knowledge of glial biology during development is exponentially expanding but hasn't developed sufficiently for development of effective neuroregenerative therapies. This review summarizes the current state of knowledge for the roles of glia in infants with EoP and its animal models, and a description of known glial-cell interactions in the context of EoP, such as the roles for border-associated macrophages. The field of perinatal medicine is relatively small but has worked passionately to improve our understanding of the etiology of EoP coupled with detailed mechanistic studies of pre-clinical and human cohorts. A primary finding from this review is that expanding our collaborations with computational biologists, working together to understand the complexity of glial subtypes, glial maturation, and the impacts of EoP in the short and long term will be key to the design of therapies that improve outcomes.

Innovative drug delivery strategies to the CNS for the treatment of multiple sclerosis

Disorders of the central nervous system (CNS), such as multiple sclerosis (MS) represent a great emotional, financial and social burden. Despite intense efforts, great unmet medical needs remain in that field. MS is an autoimmune, chronic inflammatory demyelinating disease with no curative treatment up to date. The current therapies mostly act in the periphery and seek to modulate aberrant immune responses as well as slow down the progression of the disease. Some of these therapies are associated with adverse effects related partly to their administration route and show some limitations due to their rapid clearance and inability to reach the CNS. The scientific community have recently focused their research on developing MS therapies targeting different processes within the CNS. However, delivery of therapeutics to the CNS is mainly limited by the presence of the blood-brain barrier (BBB). Therefore, there is a pressing need to develop new drug delivery strategies that ensure CNS availability to capitalize on identified therapeutic targets. Several approaches have been developed to overcome or bypass the BBB and increase delivery of therapeutics to the CNS. Among these strategies, the use of alternative routes of administration, such as the nose-to-brain (N2B) pathway, offers a promising non-invasive option in the scope of MS, as it would allow a direct transport of the drugs from the nasal cavity to the brain. Moreover, the combination of bioactive molecules within nanocarriers bring forth new opportunities for MS therapies, allowing and/or increasing their transport to the CNS. Here we will review and discuss these alternative administration routes as well as the nanocarrier approaches useful to deliver drugs for MS.

Oligodendrocyte progenitor cells in Alzheimer's disease: from physiology to pathology

Oligodendrocyte progenitor cells (OPCs) play pivotal roles in myelin formation and phagocytosis, communicating with neighboring cells and contributing to the integrity of the blood-brain barrier (BBB). However, under the pathological circumstances of Alzheimer's disease (AD), the brain's microenvironment undergoes detrimental changes that significantly impact OPCs and their functions. Starting with OPC functions, we delve into the transformation of OPCs to myelin-producing oligodendrocytes, the intricate signaling interactions with other cells in the central nervous system (CNS), and the fascinating process of phagocytosis, which influences the function of OPCs and affects CNS homeostasis. Moreover, we discuss the essential role of OPCs in BBB formation and highlight the critical contribution of OPCs in forming CNS-protective barriers. In the context of AD, the deterioration of the local microenvironment in the brain is discussed, mainly focusing on neuroinflammation, oxidative stress, and the accumulation of toxic proteins. The detrimental changes disturb the delicate balance in the brain, impacting the regenerative capacity of OPCs and compromising myelin integrity. Under pathological conditions, OPCs experience significant alterations in migration and proliferation, leading to impaired differentiation and a reduced ability to produce mature oligodendrocytes. Moreover, myelin degeneration and formation become increasingly active in AD, contributing to progressive neurodegeneration. Finally, we summarize the current therapeutic approaches targeting OPCs in AD. Strategies to revitalize OPC senescence, modulate signaling pathways to enhance OPC differentiation, and explore other potential therapeutic avenues are promising in alleviating the impact of AD on OPCs and CNS function. In conclusion, this review highlights the indispensable role of OPCs in CNS function and their involvement in the pathogenesis of AD. The intricate interplay between OPCs and the AD brain microenvironment underscores the complexity of neurodegenerative diseases. Insights from studying OPCs under pathological conditions provide a foundation for innovative therapeutic strategies targeting OPCs and fostering neurodegeneration. Future research will advance our understanding and management of neurodegenerative diseases, ultimately offering hope for effective treatments and improved quality of life for those affected by AD and related disorders.

AimSeg: A machine-learning-aided tool for axon, inner tongue and myelin segmentation

Electron microscopy (EM) images of axons and their ensheathing myelin from both the central and peripheral nervous system are used for assessing myelin formation, degeneration (demyelination) and regeneration (remyelination). The g-ratio is the gold standard measure of assessing myelin thickness and quality, and traditionally is determined from measurements made manually from EM images-a time-consuming endeavour with limited reproducibility. These measurements have also historically neglected the innermost uncompacted myelin sheath, known as the inner tongue. Nonetheless, the inner tongue has been shown to be important for myelin growth and some studies have reported that certain conditions can elicit its enlargement. Ignoring this fact may bias the standard g-ratio analysis, whereas quantifying the uncompacted myelin has the potential to provide novel insights in the myelin field. In this regard, we have developed AimSeg, a bioimage analysis tool for axon, inner tongue and myelin segmentation. Aided by machine learning classifiers trained on transmission EM (TEM) images of tissue undergoing remyelination, AimSeg can be used either as an automated workflow or as a user-assisted segmentation tool. Validation results on TEM data from both healthy and remyelinating samples show good performance in segmenting all three fibre components, with the assisted segmentation showing the potential for further improvement with minimal user intervention. This results in a considerable reduction in time for analysis compared with manual annotation. AimSeg could also be used to build larger, high quality ground truth datasets to train novel deep learning models. Implemented in Fiji, AimSeg can use machine learning classifiers trained in ilastik. This, combined with a user-friendly interface and the ability to quantify uncompacted myelin, makes AimSeg a unique tool to assess myelin growth.

Nanomaterial payload delivery to central nervous system glia for neural protection and repair

Central nervous system (CNS) glia, including astrocytes, microglia, and oligodendrocytes, play prominent roles in traumatic injury and degenerative disorders. Due to their importance, active pharmaceutical ingredients (APIs) are being developed to modulate CNS glia in order to improve outcomes in traumatic injury and disease. While many of these APIs show promise in vitro, the majority of APIs that are systemically delivered show little penetration through the blood-brain barrier (BBB) or blood-spinal cord barrier (BSCB) and into the CNS, rendering them ineffective. Novel nanomaterials are being developed to deliver APIs into the CNS to modulate glial responses and improve outcomes in injury and disease. Nanomaterials are attractive options as therapies for central nervous system protection and repair in degenerative disorders and traumatic injury due to their intrinsic capabilities in API delivery. Nanomaterials can improve API accumulation in the CNS by increasing permeation through the BBB of systemically delivered APIs, extending the timeline of API release, and interacting biophysically with CNS cell populations due to their mechanical properties and nanoscale architectures. In this review, we present the recent advances in the fields of both locally implanted nanomaterials and systemically administered nanoparticles developed for the delivery of APIs to the CNS that modulate glial activity as a strategy to improve outcomes in traumatic injury and disease. We identify current research gaps and discuss potential developments in the field that will continue to translate the use of glia-targeting nanomaterials to the clinic.

Myelin sheath injury and repairment after subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) can lead to damage to the myelin sheath in white matter. Through classification and analysis of relevant research results, the discussion in this paper provides a deeper understanding of the spatiotemporal change characteristics, pathophysiological mechanisms and treatment strategies of myelin sheath injury after SAH. The research progress for this condition was also systematically reviewed and compared related to myelin sheath in other fields. Serious deficiencies were identified in the research on myelin sheath injury and treatment after SAH. It is necessary to focus on the overall situation and actively explore different treatment methods based on the spatiotemporal changes in the characteristics of the myelin sheath, as well as the initiation, intersection and common action point of the pathophysiological mechanism, to finally achieve accurate treatment. We hope that this article can help researchers in this field to further clarify the challenges and opportunities in the current research on myelin sheath injury and treatment after SAH.

Nanoparticle Targeting with Antibodies in the Central Nervous System

Treatments for disease in the central nervous system (CNS) are limited because of difficulties in agent penetration through the blood-brain barrier, achieving optimal dosing, and mitigating off-target effects. The prospect of precision medicine in CNS treatment suggests an opportunity for therapeutic nanotechnology, which offers tunability and adaptability to address specific diseases as well as targetability when combined with antibodies (Abs). Here, we review the strategies to attach Abs to nanoparticles (NPs), including conventional approaches of chemisorption and physisorption as well as attempts to combine irreversible Ab immobilization with controlled orientation. We also summarize trends that have been observed through studies of systemically delivered Ab-NP conjugates in animals. Finally, we discuss the future outlook for Ab-NPs to deliver therapeutics into the CNS.

CNS Delivery of Nucleic Acid Therapeutics: Beyond the Blood-Brain Barrier and Towards Specific Cellular Targeting

Nucleic acid-based therapeutic molecules including small interfering RNA (siRNA), microRNA(miRNA), antisense oligonucleotides (ASOs), messenger RNA (mRNA), and DNA-based gene therapy have tremendous potential for treating diseases in the central nervous system (CNS). However, achieving clinically meaningful delivery to the brain and particularly to target cells and sub-cellular compartments is typically very challenging. Mediating cell-specific delivery in the CNS would be a crucial advance that mitigates off-target effects and toxicities. In this review, we describe these challenges and provide contemporary evidence of advances in cellular and sub-cellular delivery using a variety of delivery mechanisms and alternative routes of administration, including the nose-to-brain approach. Strategies to achieve subcellular localization, endosomal escape, cytosolic bioavailability, and nuclear transfer are also discussed. Ultimately, there are still many challenges to translating these experimental strategies into effective and clinically viable approaches for treating patients.

Intranasal Leukemia Inhibitory Factor Attenuates Gliosis and Axonal Injury and Improves Sensorimotor Function After a Mild Pediatric Traumatic Brain Injury

Leukemia inhibitory factor (LIF) is a neuroprotective cytokine that is essential for appropriate glial responses, remyelination, and preservation of neuronal conductance after injury. The intranasal route for delivery of therapeutics to the central nervous system is of particular interest given that it bypasses the blood-brain barrier and peripheral clearance systems. We explored the possibility that LIF might improve neurological function when administered intranasally during the acute phase in a pediatric model of mild traumatic brain injury (mTBI). We tested two doses of LIF and evaluated behavioral outcomes. Here, we show that acute 40-ng intranasal LIF treatment twice a day for 3 days attenuates astrogliosis and microgliosis, protects against axonal damage, significantly improves sensorimotor function, and is well tolerated without detrimental effects on growth. Altogether, our studies provide pre-clinical evidence for the use of acute intranasal LIF treatment as a viable therapeutic for pediatric cases of mTBIs.

Identifying Genes that Affect Differentiation of Human Neural Stem Cells and Myelination of Mature Oligodendrocytes

Human neural stem cells (NSCs) are self-renewing, multipotent cells of the central nervous system (CNS). They are characterized by their ability to differentiate into a range of cells, including oligodendrocytes (OLs), neurons, and astrocytes, depending on exogenous stimuli. An efficient and easy directional differentiation method was developed for obtaining large quantities of high-quality of human OL progenitor cells (OPCs) and OLs from NSCs. RNA sequencing, immunofluorescence staining, flow cytometry, western blot, label-free proteomic sequencing, and qPCR were performed in OL lines differentiated from NSC lines. The changes in the positive rate of typical proteins were analyzed expressed by NSCs, neurons, astrocytes, OPCs, and OLs. We assessed Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of differentially expressed (DE) messenger RNAs (mRNAs) related to the differentiation of NSCs and the maturation of OLs. The percentage of NSCs differentiated into neurons, astrocytes, and OLs was 82.13%, 80.19%, and 90.15%, respectively. We found that nestin, PAX6, Musashi, and vimentin were highly expressed in NSCs; PDGFR-α, A2B5, NG2, OLIG2, SOX10, and NKX2-2 were highly expressed in OPCs; and CNP, GALC, PLP1, and MBP were highly expressed in OLs. RNA sequencing, western blot and qPCR revealed that ERBB4 and SORL1 gradually increased during NSC–OL differentiation. In conclusion, NSCs can differentiate into neurons, astrocytes, and OLs efficiently. PDGFR-α, APC, ID4, PLLP, and other markers were related to NSC differentiation and OL maturation. Moreover, we refined a screening method for ERBB4 and SORL1, which may underlie NSC differentiation and OL maturation.

Graphical Abstract

Potential unreported genes and proteins may regulate differentiation of human neural stem cells into oligodendrocyte lineage. Neural stem cells (NSCs) can differentiate into neurons, astrocytes, and oligodendrocyte (OLs) efficiently. By analyzing the DE mRNAs and proteins of NSCs and OLs lineage, we could identify reported markers and unreported markers of ERBB4 and SORL1 that may underlie regulate NSC differentiation and OL maturation.

Glial cells and neurologic autoimmune disorders

Neurologic autoimmune disorders affect people's physical and mental health seriously. Glial cells, as an important part of the nervous system, play a vital role in the occurrence of neurologic autoimmune disorders. Glial cells can be hyperactivated in the presence of autoantibodies or pathological changes, to influence neurologic autoimmune disorders. This review is mainly focused on the roles of glial cells in neurologic autoimmune disorders and the influence of autoantibodies produced by autoimmune disorders on glial cells. We speculate that the possibility of glial cells might be a novel way for the investigation and therapy of neurologic autoimmune disorders.

Potential biomarkers for diagnosis and assessment of disease activity in systemic lupus erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease involving multiple system functions. Our study aimed to screen out more effective new indicators that can assist clinical diagnosis and judge disease activity.

METHODS

We first screened serum levels of 45 cytokines of SLE patients (n = 3) and healthy controls (n = 3). Subsequently, we selected five elevated cytokines for verification with an expanded sample size. Then, the relationship between cytokines and laboratory parameters was also investigated. Finally, we used receiver operating characteristic (ROC) curves to assess the clinical value of these cytokines.

RESULTS

Through screening of 45 cytokines, 15 were found to be elevated in SLE patients. We chose five cytokines (IL-6, IL-10, IL-1RA, IP-10 and LIF) for further research and found elevated expression of all five cytokines in SLE patients. Serum levels of IL-10, IL-1RA and LIF were positively correlated with SLEDAI-2K score. Besides, the level of IL-10 was significantly positively correlated with serum IgG and erythrocyte sedimentation rate (ESR); IL-1RA was significantly negatively correlated with C3 and C4; and LIF was significantly positively correlated with serum IgG, C-reactive protein (CRP), and ESR. Furthermore, IL-1RA and LIF were strongly positively correlated with 24-hour urine protein levels. The ROC analysis showed that IL-1RA has good diagnostic value, and IL-10 and LIF levels can be utilized to discriminate between active and inactive SLE.

CONCLUSION

IL-1RA can be used as a biomarker for diagnosing SLE, while IL-10 and LIF can be indicators to discriminate between active and inactive SLE.

Targeting Fibronectin to Overcome Remyelination Failure in Multiple Sclerosis: The Need for Brain- and Lesion-Targeted Drug Delivery

Multiple sclerosis (MS) is a neuroinflammatory and neurodegenerative disease with unknown etiology that can be characterized by the presence of demyelinated lesions. Prevailing treatment protocols in MS rely on the modulation of the inflammatory process but do not impact disease progression. Remyelination is an essential factor for both axonal survival and functional neurological recovery but is often insufficient. The extracellular matrix protein fibronectin contributes to the inhibitory environment created in MS lesions and likely plays a causative role in remyelination failure. The presence of the blood–brain barrier (BBB) hinders the delivery of remyelination therapeutics to lesions. Therefore, therapeutic interventions to normalize the pathogenic MS lesion environment need to be able to cross the BBB. In this review, we outline the multifaceted roles of fibronectin in MS pathogenesis and discuss promising therapeutic targets and agents to overcome fibronectin-mediated inhibition of remyelination. In addition, to pave the way for clinical use, we reflect on opportunities to deliver MS therapeutics to lesions through the utilization of nanomedicine and discuss strategies to deliver fibronectin-directed therapeutics across the BBB. The use of well-designed nanocarriers with appropriate surface functionalization to cross the BBB and target the lesion sites is recommended.

The effect of Zingiber Officinale Extract on Preventing Demyelination of Corpus Callosum in a Rat Model of Multiple Sclerosis

Background

Multiple sclerosis (MS) is the most prevalent neurological disability of young adults. Anti-inflammatory drugs have relative effects on MS. The anti-inflammatory and antioxidative effects of Zingiber officinale (ginger) have been proven in some experimental and clinical investigations. The aim of this study was to evaluate the effects of ginger extract on preventing myelin degradation in a rat model of MS.

Methods

Forty nine male Wistar rats were used in this study and divided into four control groups: the normal group, cuprizone-induced group, sham group (cuprizone [CPZ] + sodium carboxymethyl cellulose [NaCMC]), standard control group (fingolimod + cuprizone), including three experimental groups of CPZ, each receiving three different doses of ginger extract: 150, 300, and 600mg/kg /kg/day.

Results

Ginger extract of 600 mg/kg prevented corpus callosum from demyelination; however, a significant difference was observed in the fingolimod group (p < 0.05). Difference in the CPZ group was quite significant (p < 0.05).

Conclusion

Treatment with ginger inhibited demyelination and alleviated remyelination of corpus callosum in rats. Therefore, it could serve as a therapeutic agent in the MS.

Brain drug delivery and neurodegenerative diseases: Polymeric PLGA-based nanoparticles as a forefront platform

The discovery of effective drugs for the treatment of neurodegenerative disorders (NDs) is a deadlock. Due to their complex etiology and high heterogeneity, progresses in the development of novel NDs therapies have been slow, raising social/economic and medical concerns. Nanotechnology and nanomedicine evolved exponentially in recent years and presented a panoply of tools projected to improve diagnosis and treatment. Drug-loaded nanosystems, particularly nanoparticles (NPs), were successfully used to address numerous drug glitches, such as efficacy, bioavailability and safety. Polymeric nanoparticles (PNPs), mainly based on polylactic-co-glycolic acid (PLGA), have been already validated and approved for the treatment of cancer, neurologic dysfunctions and hormonal-related diseases. Despite promising no PNPs-based therapy for neurodegenerative disorders is available up to date. To stimulate the research in the area the studies performed so far with polylactic-co-glycolic acid (PLGA) nanoparticles as well as the techniques aimed to improve PNPs BBB permeability and drug targeting were revised. Bearing in mind NDs pharmacological therapy landscape huge efforts must be done in finding new therapeutic solutions along with the translation of the most promising results to the clinic, which hopefully will converge in the development of effective drugs in a foreseeable future.

Targeted Delivery Platforms for the Treatment of Multiple Sclerosis

Multiple sclerosis (MS) is a neurodegenerative condition of the central nervous system (CNS) that presents with varying levels of disability in patients, displaying the significance of timely and effective management of this complication. Though several treatments have been developed to protect nerves, comprehensive improvement of MS is still considered an essential bottleneck. Therefore, the development of innovative treatment methods for MS is one of the core research areas. In this regard, nanoscale platforms can offer practical and ideal approaches to the diagnosis and treatment of various diseases, especially immunological disorders such as MS, to improve the effectiveness of conventional therapies. It should be noted that there is significant progress in the development of neuroprotective strategies through the implementation of various nanoparticles, monoclonal antibodies, peptides, and aptamers. In this study, we summarize different particle systems as well as targeted therapies, such as antibodies, peptides, nucleic acids, and engineered cells for the treatment of MS, and discuss their potential in the treatment of MS in the preclinical and clinical stages. Future advances in targeted delivery of medical supplies may offer new strategies for complete recovery as well as practical treatment of progressive forms of MS.

Nimodipine Exerts Beneficial Effects on the Rat Oligodendrocyte Cell Line OLN-93

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS). Therapy is currently limited to drugs that interfere with the immune system; treatment options that primarily mediate neuroprotection and prevent neurodegeneration are not available. Here, we studied the effects of nimodipine on the rat cell line OLN-93, which resembles young mature oligodendrocytes. Nimodipine is a dihydropyridine that blocks the voltage-gated L-type calcium channel family members Cav1.2 and Cav1.3. Our data show that the treatment of OLN-93 cells with nimodipine induced the upregulation of myelin genes, in particular of proteolipid protein 1 (Plp1), which was confirmed by a significantly greater expression of PLP1 in immunofluorescence analysis and the presence of myelin structures in the cytoplasm at the ultrastructural level. Whole-genome RNA sequencing additionally revealed the upregulation of genes that are involved in neuroprotection, remyelination, and antioxidation pathways. Interestingly, the observed effects were independent of Cav1.2 and Cav1.3 because OLN-93 cells do not express these channels, and there was no measurable response pattern in patch-clamp analysis. Taking into consideration previous studies that demonstrated a beneficial effect of nimodipine on microglia, our data support the notion that nimodipine is an interesting drug candidate for the treatment of MS and other demyelinating diseases.

Epithelial LIF signaling limits apoptosis and lung injury during bacterial pneumonia

During bacterial pneumonia, alveolar epithelial cells are critical for maintaining gas exchange and providing antimicrobial as well as pro-immune properties. We previously demonstrated that leukemia inhibitory factor (LIF), an IL-6 family cytokine, is produced by type II alveolar epithelial cells (ATII) and is critical for tissue protection during bacterial pneumonia. However, the target cells and mechanisms of LIF-mediated protection remain unknown. Here, we demonstrate that antibody-induced LIF blockade remodels the lung epithelial transcriptome in association with increased apoptosis. Based on these data, we performed pneumonia studies using a novel mouse model in which LIFR (the unique receptor for LIF) is absent in lung epithelium. Although LIFR is expressed on the surface of epithelial cells, its absence only minimally contributed to tissue protection during pneumonia. Single-cell RNA-sequencing (scRNAseq) was conducted to identify adult murine lung cell types most prominently expressing Lifr, revealing endothelial cells, mesenchymal cells, and ATIIs as major sources of Lifr. Sequencing data indicated that ATII cells were significantly impacted by pneumonia, with additional differences observed in response to LIF neutralization, including but not limited to gene programs related to cell death, injury, and inflammation. Overall, our data suggest that LIF signaling on epithelial cells alters responses in this cell type during pneumonia. However, our results also suggest separate and perhaps more prominent roles of LIFR in other cell types, such as endothelial cells or mesenchymal cells, which provide grounds for future investigation.

Microglia as therapeutic targets for central nervous system remyelination

Failed remyelination underpins neurodegeneration and central nervous system (CNS) dysfunction with aging and progression of neurological diseases, such as multiple sclerosis and Alzheimer's disease. Existing therapies have shown limited efficacy in halting disease progression in humans, highlighting the need to identify pro-remyelination treatments. Microglia are CNS-resident macrophages with critical roles in the regulation of remyelination, representing a promising therapeutic target. However, there are currently no therapeutics which specifically target microglia. Recent studies have revealed that microglia are a heterogenous population with distinct transcriptional states in health and disease conditions, including during remyelination, suggesting functional differences between states. Here, we discuss the potential contributions of different microglia states to degenerative and regenerative processes, examine the potential to target microglia in a state-specific manner to promote remyelination and consider the key issues to be addressed before such therapies can be clinically applied.

Recent advancements in nanoparticle-mediated approaches for restoration of multiple sclerosis

Multiple Sclerosis (MS) is an autoimmune disease with complicated immunopathology which necessitates considering multifactorial aspects for its management. Nano-sized pharmaceutical carriers named nanoparticles (NPs) can support impressive management of disease not only in early detection and prognosis level but also in a therapeutic manner. The most prominent initiator of MS is the domination of cellular immunity to humoral immunity and increment of inflammatory cytokines. The administration of several platforms of NPs for MS management holds great promise so far. The efforts for MS management through in vitro and in vivo (experimental animal models) evaluations, pave a new way to a highly efficient therapeutic means and aiding its translation to the clinic in the near future.

The emerging role of the chondroitin sulfate proteoglycan family in neurodegenerative diseases

Chondroitin sulfate (CS) is a kind of linear polysaccharide that is covalently linked to proteins to form proteoglycans. Chondroitin sulfate proteoglycans (CSPGs) consist of a core protein, with one or more CS chains covalently attached. CSPGs are precisely regulated and they exert a variety of physiological functions by binding to adhesion molecules and growth factors. Widely distributed in the nervous system in human body, CSPGs contribute to the major component of extracellular matrix (ECM), where they play an important role in the development and maturation of the nervous system, as well as in the pathophysiological response to damage to the central nervous system (CNS). While there are more than 30 types of CSPGs, this review covers the roles of the most important ones, including versican, aggrecan, neurocan and NG2 in the pathogenesis of neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and multiple sclerosis. The updated reports of the treatment of neurodegenerative diseases are involving CSPGs.

Oligodendrocyte progenitor proliferation is disinhibited following traumatic brain injury in leukemia inhibitory factor heterozygous mice

Traumatic brain injury (TBI) is a significant problem that affects over 800,000 children each year. As cell proliferation is disturbed by injury and required for normal brain development, we investigated how a pediatric closed head injury (CHI) would affect the progenitors of the subventricular zone (SVZ). Additionally, we evaluated the contribution of leukemia inhibitory factor (LIF) using germline LIF heterozygous mice (LIF Het), as LIF is an injury-induced cytokine, known to influence neurogenesis and gliogenesis. CHIs were performed on P20 LIF Het and wild-type (WT) mice. Ki-67 immunostaining and stereology revealed that cell proliferation increased ~250% in injured LIF Het mice compared to the 30% increase observed in injured WT mice at 48-hr post-CHI. OLIG2+ cell proliferation increased in the SVZ and white matter of LIF Het injured mice at 48-hr recovery. Using an 8-color flow cytometry panel, the proliferation of three distinct multipotential progenitors and early oligodendrocyte progenitor cell proliferation was significantly increased in LIF Het injured mice compared to WT injured mice. Supporting its cytostatic function, LIF decreased neurosphere progenitor and oligodendrocyte progenitor cell proliferation compared to controls. In highly enriched mouse oligodendrocyte progenitor cell cultures, LIF increased phospho-protein kinase B after 20 min and increased phospho-S6 ribosomal protein at 20 and 40 min of exposure, which are downstream targets of the mammalian target of rapamycin pathway. Altogether, our data provide new insights into the regulatory role of LIF in suppressing neural progenitor cell proliferation and, in particular, oligodendrocyte progenitor cell proliferation after a mild TBI.

Activation of 5-HT1A receptor reduces abnormal emotionality in stress-maladaptive mice by alleviating decreased myelin protein in the ventral hippocampus

We previously reported that abnormal emotionality in stress-maladaptive mice was ameliorated by chronic treatment with flesinoxan, a 5-HT_1A receptor agonist. Furthermore, the maintenance of hippocampal myelination appeared to contribute to the development of stress adaptation in mice. However, the effects of 5-HT_1A receptor activation on myelination under the stress-maladaptive situations and the underlying mechanisms remain unknown. In the present study, we examined using flesinoxan whether activation of 5-HT_1A receptor can reduce an abnormal emotional response by acting on oligodendrocytes to preserve myelin proteins in stress-maladaptive mice. Mice were exposed to repeated restraint stress for 4 h/day for 14 days as a stress-maladaptive model. Flesinoxan was given intraperitoneally immediately after the daily exposure to restraint stress. After the final exposure to restraint stress, the emotionality of mice was evaluated by the hole-board test. The expression levels of brain-derived neurotrophic factor (BDNF), phosphorylated-extracellular signal-regulated kinase (p-ERK), phosphorylated-cAMP response element-binding protein (p-CREB), myelin-associated glycoprotein (MAG), myelin basic protein (MBP) and oligodendrocyte transcription factor 2 (olig2) in the hippocampus was assessed by western blotting. Hippocampal oligodendrogenesis were examined by immunohistochemistry. Chronic treatment with flesinoxan suppressed the decrease in head-dipping behaviors in stress-maladaptive mice in the hole-board test. Under this condition, the decreases in MAG and MBP in the hippocampus recovered with increase in BDNF, p-ERK, p-CREB, and olig2. Furthermore, hippocampal oligodendrogenesis in stress-maladaptive mice was promoted by chronic treatment with flesinoxan. These findings suggest that 5-HT_1A receptor activation may promote oligodendrogenesis and myelination via an ERK/CREB/BDNF signaling pathway in the hippocampus and reduces abnormal emotionality due to maladaptation to excessive stress.

Nanosystems and exosomes as future approaches in treating multiple sclerosis

Multiple sclerosis (MS) is an immune-mediated demyelinating disease of the central nervous system which leads to neurological dysfunctions and severe disabilities. MS pathology is characterised by damage of the blood-brain barrier and infiltration of autoreactive T cells that overactivate glial cells, thereby initiating neuroinflammation accompanied by the formation of demyelinating plaques and neurodegeneration. Clinical deficits in this multifactorial disease depend on the progression of myelin loss, the stage of inflammation, the status of axons and the activity of oligodendrocyte precursor cells (OPCs). Despite significant progress in the treatment of MS, current therapies remain limited and new approaches are highly desirable. Nanosystems based on liposomes and nanoparticles are among some of the more noteworthy therapeutic strategies being investigated. Applications of nanosystems alone or as drug carriers in animal models of MS have been found to successfully alleviate the symptoms of the disease and exert anti-inflammatory potential. Exosomes are a specific type of nanosystem based on nanometre-sized extracellular vesicles released by different cells which exhibit important healing features. Exosomes contain an array of anti-inflammatory and neuroprotective agents which may contribute to modulation of the immune system as well as promoting remyelination and tissue repair. In this review, opportunities to use nanosystems against progression of MS will be discussed in context of cell-specific pathologies associated with MS.

Aligned fibrin/functionalized self-assembling peptide interpenetrating nanofiber hydrogel presenting multi-cues promotes peripheral nerve functional recovery

Nerve guidance conduits with hollow lumen fail to regenerate critical-sized peripheral nerve defects (15 mm in rats and 25 mm in humans), which can be improved by a beneficial intraluminal microenvironment. However, individual cues provided by intraluminal filling materials are inadequate to eliminate the functional gap between regenerated nerves and normal nerves. Herein, an aligned fibrin/functionalized self-assembling peptide (AFG/fSAP) interpenetrating nanofiber hydrogel that exerting synergistic topographical and biochemical cues for peripheral nerve regeneration is constructed via electrospinning and molecular self-assembly. The hydrogel possesses an aligned structure, high water content, appropriate mechanical properties and suitable biodegradation capabilities for nerve repair, which enhances the alignment and neurotrophin secretion of primary Schwann cells (SCs) in vitro, and successfully bridges a 15-mm sciatic nerve gap in rats in vivo. The rats transplanted with the AFG/fSAP hydrogel exhibit satisfactory morphological and functional recovery in myelinated nerve fibers and innervated muscles. The motor function recovery facilitated by the AFG/fSAP hydrogel is comparable with that of autografts. Moreover, the AFG/fSAP hydrogel upregulates the regeneration-associated gene expression and activates the PI3K/Akt and MAPK signaling pathways in the regenerated nerve. Altogether, the AFG/fSAP hydrogel represents a promising approach for peripheral nerve repair through an integration of structural guidance and biochemical stimulation.

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A novel aligned interpenetrating nanofiber hydrogel is first constructed for peripheral nerve regeneration.

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The aligned hydrogel presents synergistic topographical and biochemical cues for peripheral nerve regeneration.

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Nerve conduits filled with the aligned hydrogel can repair the long-distance sciatic nerve defects in 12 weeks.

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The function recovery facilitated by the aligned hydrogel is comparable with that of autografts.

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The aligned hydrogel upregulates regeneration-related genes and activates the PI3K/Akt and MAPK signaling pathways.

Multiple Sclerosis: Focus on Extracellular and Artificial Vesicles, Nanoparticles as Potential Therapeutic Approaches

Multiple sclerosis (MS) is an autoimmune disease of the Central Nervous System, characterized by an inflammatory process leading to the destruction of myelin with neuronal death and neurodegeneration. In MS, lymphocytes cross the blood-brain barrier, creating inflammatory demyelinated plaques located primarily in the white matter. MS potential treatments involve various mechanisms of action on immune cells, immunosuppression, inhibition of the passage through the blood-brain barrier, and immunotolerance. Bio-nanotechnology represents a promising approach to improve the treatment of autoimmune diseases by its ability to affect the immune responses. The use of nanotechnology has been actively investigated for the development of new MS therapies. In this review, we summarize the results of the studies on natural and artificial vesicles and nanoparticles, and take a look to the future clinical perspectives for their application in the MS therapy.

PLGA-Based Nanoparticles for Neuroprotective Drug Delivery in Neurodegenerative Diseases

Treatment of neurodegenerative diseases has become one of the most challenging topics of the last decades due to their prevalence and increasing societal cost. The crucial point of the non-invasive therapeutic strategy for neurological disorder treatment relies on the drugs' passage through the blood-brain barrier (BBB). Indeed, this biological barrier is involved in cerebral vascular homeostasis by its tight junctions, for example. One way to overcome this limit and deliver neuroprotective substances in the brain relies on nanotechnology-based approaches. Poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) are biocompatible, non-toxic, and provide many benefits, including improved drug solubility, protection against enzymatic digestion, increased targeting efficiency, and enhanced cellular internalization. This review will present an overview of the latest findings and advances in the PLGA NP-based approach for neuroprotective drug delivery in the case of neurodegenerative disease treatment (i.e., Alzheimer's, Parkinson's, Huntington's diseases, Amyotrophic Lateral, and Multiple Sclerosis).

Strategies to Use Nanoparticles to Generate CD4 and CD8 Regulatory T Cells for the Treatment of SLE and Other Autoimmune Diseases

Autoimmune diseases are disorders of immune regulation where the mechanisms responsible for self-tolerance break down and pathologic T cells overcome the protective effects of T regulatory cells (Tregs) that normally control them. The result can be the initiation of chronic inflammatory diseases. Systemic lupus erythematosus (SLE) and other autoimmune diseases are generally treated with pharmacologic or biological agents that have broad suppressive effects. These agents can halt disease progression, yet rarely cure while carrying serious adverse side effects. Recently, nanoparticles have been engineered to correct homeostatic regulatory defects and regenerate therapeutic antigen-specific Tregs. Some approaches have used nanoparticles targeted to antigen presenting cells to switch their support from pathogenic T cells to protective Tregs. Others have used nanoparticles targeted directly to T cells for the induction and expansion of CD4+ and CD8+ Tregs. Some of these T cell targeted nanoparticles have been formulated to act as tolerogenic artificial antigen presenting cells. This article discusses the properties of these various nanoparticle formulations and the strategies to use them in the treatment of autoimmune diseases. The restoration and maintenance of Treg predominance over effector cells should promote long-term autoimmune disease remission and ultimately prevent them in susceptible individuals.

Cross-Talk of the CNS With Immune Cells and Functions in Health and Disease

The immune system's role is much more than merely recognizing self vs. non-self and involves maintaining homeostasis and integrity of the organism starting from early development to ensure proper organ function later in life. Unlike other systems, the central nervous system (CNS) is separated from the peripheral immune machinery that, for decades, has been envisioned almost entirely as detrimental to the nervous system. New research changes this view and shows that blood-borne immune cells (both adaptive and innate) can provide homeostatic support to the CNS via neuroimmune communication. Neurodegeneration is mostly viewed through the lens of the resident brain immune populations with little attention to peripheral circulation. For example, cognition declines with impairment of peripheral adaptive immunity but not with the removal of microglia. Therapeutic failures of agents targeting the neuroinflammation framework (inhibiting immune response), especially in neurodegenerative disorders, call for a reconsideration of immune response contributions. It is crucial to understand cross-talk between the CNS and the immune system in health and disease to decipher neurodestructive and neuroprotective immune mechanisms for more efficient therapeutic strategies.

Biomaterial-based immunoengineering to fight COVID-19 and infectious diseases

Infection by SARS-CoV-2 virus often induces the dysregulation of immune responses, tissue damage, and blood clotting. Engineered biomaterials from the nano- to the macroscale can provide targeted drug delivery, controlled drug release, local immunomodulation, enhanced immunity, and other desirable functions to coordinate appropriate immune responses and to repair tissues. Based on the understanding of COVID-19 disease progression and immune responses to SARS-CoV-2, we discuss possible immunotherapeutic strategies and highlight biomaterial approaches from the perspectives of preventive immunization, therapeutic immunomodulation, and tissue healing and regeneration. Successful development of biomaterial platforms for immunization and immunomodulation will not only benefit COVID-19 patients, but also have broad applications for a variety of infectious diseases.

Leukemia inhibitory factor regulates Schwann cell proliferation and migration and affects peripheral nerve regeneration

Leukemia inhibitory factor (LIF) is a pleiotropic cytokine that stimulates neuronal development and survival. Our previous study has demonstrated that LIF mRNA is dysregulated in the peripheral nerve segments after nerve injury. Here, we show that LIF protein is abundantly expressed in Schwann cells after rat sciatic nerve injury. Functionally, suppressed or elevated LIF increases or decreases the proliferation rate and migration ability of Schwann cells, respectively. Morphological observations demonstrate that in vivo application of siRNA against LIF after peripheral nerve injury promotes Schwann cell migration and proliferation, axon elongation, and myelin formation. Electrophysiological and behavior assessments disclose that knockdown of LIF benefits the function recovery of injured peripheral nerves. Differentially expressed LIF affects the metabolism of Schwann cells and negatively regulates ERFE (Erythroferrone). Collectively, our observations reveal the essential roles for LIF in regulating the proliferation and migration of Schwann cells and the regeneration of injured peripheral nerves, discover ERFE as a downstream effector of LIF, and extend our understanding of the molecular mechanisms underlying peripheral nerve regeneration.

Multiple Sclerosis: LIFNano-CD4 for Trojan Horse Delivery of the Neuro-Protective Biologic “LIF” Into the Brain: Preclinical Proof of Concept

Multiple sclerosis (MS) is a demyelinating autoimmune disease that attacks the brain, with year-on-year loss of brain volume, starting late teens and becoming manifest late twenties. There is no cure, and current therapies are immunosuppressive only. LIF is a vital stem cell growth factor active throughout life—and essential for health of the central nervous system (CNS), being tolerogenic, myelinogenic, and neuroprotective. Nano-formulation of LIF (LIFNano) using FDA-approved PLGA captures LIF's compound therapeutic properties, increasing potency 1,000-fold when targeted to CD4 (LIFNano-CD4). Moreover, circulating CD4⁺ lymphocytes are themselves regulated by LIF to express the Treg phenotype, known to release T cell-derived LIF upon engagement with cognate antigen, perpetuating antigen-specific self-tolerance. With the longer-term aim of treating inflammatory lesions of MS, we asked, does LIFNano-CD4 cross the blood–brain barrier (BBB)? We measure pK and pD using novel methodologies, demonstrate crossing of the BBB, show LIF-cargo-specific anti-inflammatory efficacy in the frontal cortex of the brain, and show safety of intravenous delivery of LIFNano-CD4 at doses known to provide efficacious concentrations of LIF cargo behind the BBB.

Cell signaling pathways in autosomal-dominant leukodystrophy (ADLD): the intriguing role of the astrocytes

Autosomal-dominant leukodystrophy (ADLD) is a rare fatal neurodegenerative disorder with overexpression of the nuclear lamina component, Lamin B1 due to LMNB1 gene duplication or deletions upstream of the gene. The molecular mechanisms responsible for driving the onset and development of this pathology are not clear yet. Vacuolar demyelination seems to be one of the most significant histopathological observations of ADLD. Considering the role of oligodendrocytes, astrocytes, and leukemia inhibitory factor (LIF)-activated signaling pathways in the myelination processes, this work aims to analyze the specific alterations in different cell populations from patients with LMNB1 duplications and engineered cellular models overexpressing Lamin B1 protein. Our results point out, for the first time, that astrocytes may be pivotal in the evolution of the disease. Indeed, cells from ADLD patients and astrocytes overexpressing LMNB1 show severe ultrastructural nuclear alterations, not present in oligodendrocytes overexpressing LMNB1. Moreover, the accumulation of Lamin B1 in astrocytes induces a reduction in LIF and in LIF-Receptor (LIF-R) levels with a consequential decrease in LIF secretion. Therefore, in both our cellular models, Jak/Stat3 and PI3K/Akt axes, downstream of LIF/LIF-R, are downregulated. Significantly, the administration of exogenous LIF can partially reverse the toxic effects induced by Lamin B1 accumulation with differences between astrocytes and oligodendrocytes, highlighting that LMNB1 overexpression drastically affects astrocytic function reducing their fundamental support to oligodendrocytes in the myelination process. In addition, inflammation has also been investigated, showing an increased activation in ADLD patients' cells.

Programmable DNA Nanodevices for Applications in Neuroscience

The broad area of neuroscience has witnessed an increasing exploitation of a variety of synthetic biomaterials with controlled nanosized features. Different bionanomaterials offer very peculiar physicochemical and biochemcial properties contributing to the development of novel imaging devices toward imaging the brain, or as smartly functionalized scaffolds, or diverse tools contributing toward a better understanding of nervous tissue and its functions. DNA nanotechnology-based devices and scaffolds have emerged as ideal materials for cellular and tissue engineering due to their very biocompatible properties, robust adaptation with diverse biological systems, and biosafety in terms of reduced immune response triggering. Here we present technologies with respect to DNA nanodevices that are designed to better interact with nervous systems like neural cells, advanced molecular imaging technologies for imaging brain, biomaterials in neural regeneration, neuroprotection, and targeted delivery of drugs and small molecules across the blood-brain barrier. Along with comments regarding the progress of DNA nanotechnology in neuroscience, we also present a perspective on challenges and opportunities for applying DNA nanotechnology in applications pertaining to neurosciences.

The potential of biomaterials for central nervous system cellular repair

The central nervous system (CNS) can be injured or damaged through a variety of insults including traumatic injury, stroke, and neurodegenerative or demyelinating diseases, including Alzheimer's disease, Parkinson's disease and multiple sclerosis. Existing pharmacological and other therapeutics strategies are limited in their ability to repair or regenerate damaged CNS tissue meaning there are significant unmet clinical needs facing patients suffering CNS damage and/or degeneration. Through a variety of mechanisms including neuronal replacement, secretion of therapeutic factors, and stimulation of host brain plasticity, cell-based repair offers a potential mechanism to repair and heal the damaged CNS. However, over the decades of its evolution as a therapeutic strategy, cell-based CNS repair has faced significant hurdles that have prevented its translation to widespread clinical practice. In recent years, advances in cell technologies combined with advances in biomaterial-based regenerative medicine and tissue engineering have meant there is very real potential for many of these hurdles to be overcome. This review will provide an overview of the main CNS conditions that lend themselves to cellular repair and will then outline the potential of biomaterial-based approaches for improving the outcome of cellular repair in these conditions.

The impact of trophic and immunomodulatory factors on oligodendrocyte maturation: Potential treatments for encephalopathy of prematurity

Encephalopathy of prematurity (EoP) is a major cause of morbidity in preterm neonates, causing neurodevelopmental adversities that can lead to lifelong impairments. Preterm birth-related insults, such as cerebral oxygen fluctuations and perinatal inflammation, are believed to negatively impact brain development, leading to a range of brain abnormalities. Diffuse white matter injury is a major hallmark of EoP and characterized by widespread hypomyelination, the result of disturbances in oligodendrocyte lineage development. At present, there are no treatment options available, despite the enormous burden of EoP on patients, their families, and society. Over the years, research in the field of neonatal brain injury and other white matter pathologies has led to the identification of several promising trophic factors and cytokines that contribute to the survival and maturation of oligodendrocytes, and/or dampening neuroinflammation. In this review, we discuss the current literature on selected factors and their therapeutic potential to combat EoP, covering a wide range of in vitro, preclinical and clinical studies. Furthermore, we offer a future perspective on the translatability of these factors into clinical practice.

Nano Carrier Drug Delivery Systems for the Treatment of Neuropsychiatric Disorders: Advantages and Limitations

Neuropsychiatric diseases are one of the main causes of disability, affecting millions of people. Various drugs are used for its treatment, although no effective therapy has been found yet. The blood brain barrier (BBB) significantly complicates drugs delivery to the target cells in the brain tissues. One of the problem-solving methods is the usage of nanocontainer systems. In this review we summarized the data about nanoparticles drug delivery systems and their application for the treatment of neuropsychiatric disorders. Firstly, we described and characterized types of nanocarriers: inorganic nanoparticles, polymeric and lipid nanocarriers, their advantages and disadvantages. We discussed ways to interact with nerve tissue and methods of BBB penetration. We provided a summary of nanotechnology-based pharmacotherapy of schizophrenia, bipolar disorder, depression, anxiety disorder and Alzheimer's disease, where development of nanocontainer drugs derives the most active. We described various experimental drugs for the treatment of Alzheimer's disease that include vector nanocontainers targeted on β-amyloid or tau-protein. Integrally, nanoparticles can substantially improve the drug delivery as its implication can increase BBB permeability, the pharmacodynamics and bioavailability of applied drugs. Thus, nanotechnology is anticipated to overcome the limitations of existing pharmacotherapy of psychiatric disorders and to effectively combine various treatment modalities in that direction.

Nanotechnology Solutions for Controlled Cytokine Delivery: An Applied Perspective

Around 200 cytokines with roles in cell signaling have been identified and studied, with the vast majority belonging to the four-α-helix bundle family. These proteins exert their function by binding to specific receptors and are implicated in many diseases. The use of several cytokines as therapeutic targets has been approved by the FDA, however their rapid clearance in vivo still greatly limits their efficacy. Nano-based drug delivery systems have been widely applied in nanomedicine to develop safe, specific and controlled delivery techniques. Nevertheless, each nanomaterial has its own specifications and their suitability towards the biochemical and biophysical properties of the selected drug needs to be determined, weighing in the final choice of the ideal nano drug delivery system. Nanoparticles remain the most used vehicle for cytokine delivery, where polymeric carriers represent the vast majority of the studied systems. Liposomes and gold or silica nanoparticles are also explored and discussed in this review. Additionally, surface functionalization is of great importance to facilitate the attachment of a wide variety of molecules and modify features such as bioavailability. Since the monitoring of cytokine levels has an important role in early clinical diagnosis and for assessing therapeutic efficacy, nanotechnological advances are also valuable for nanosensor development.

Potential for Targeting Myeloid Cells in Controlling CNS Inflammation

Multiple Sclerosis (MS) is characterized by immune cell infiltration to the central nervous system (CNS) as well as loss of myelin. Characterization of the cells in lesions of MS patients revealed an important accumulation of myeloid cells such as macrophages and dendritic cells (DCs). Data from the experimental autoimmune encephalomyelitis (EAE) model of MS supports the importance of peripheral myeloid cells in the disease pathology. However, the majority of MS therapies focus on lymphocytes. As we will discuss in this review, multiple strategies are now in place to target myeloid cells in clinical trials. These strategies have emerged from data in both human and mouse studies. We discuss strategies targeting myeloid cell migration, growth factors and cytokines, biological functions (with a focus on miRNAs), and immunological activities (with a focus on nanoparticles).

Protective Functions of Reactive Astrocytes Following Central Nervous System Insult

Astrocytes play important roles in numerous central nervous system disorders including autoimmune inflammatory, hypoxic, and degenerative diseases such as Multiple Sclerosis, ischemic stroke, and Alzheimer’s disease. Depending on the spatial and temporal context, activated astrocytes may contribute to the pathogenesis, progression, and recovery of disease. Recent progress in the dissection of transcriptional responses to varying forms of central nervous system insult has shed light on the mechanisms that govern the complexity of reactive astrocyte functions. While a large body of research focuses on the pathogenic effects of reactive astrocytes, little is known about how they limit inflammation and contribute to tissue regeneration. However, these protective astrocyte pathways might be of relevance for the understanding of the underlying pathology in disease and may lead to novel targeted approaches to treat autoimmune inflammatory and degenerative disorders of the central nervous system. In this review article, we have revisited the emerging concept of protective astrocyte functions and discuss their role in the recovery from inflammatory and ischemic disease as well as their role in degenerative disorders. Focusing on soluble astrocyte derived mediators, we aggregate the existing knowledge on astrocyte functions in the maintenance of homeostasis as well as their reparative and tissue-protective function after acute lesions and in neurodegenerative disorders. Finally, we give an outlook of how these mediators may guide future therapeutic strategies to tackle yet untreatable disorders of the central nervous system.

Lipid Nanoparticles Vectorized with NFL-TBS.40-63 Peptide Target Oligodendrocytes and Promote Neurotrophin-3 Effects After Demyelination In Vitro

Promoting remyelination in multiple sclerosis is important to prevent axon degeneration, given the lack of curative treatment. Although some growth factors improve this repair, unspecific delivery to cells and potential side effects limit their therapeutic use. Thus, NFL-TBS.40-63 peptide (NFL)-known to enter specifically myelinating oligodendrocytes (OL)-was used to vectorize 100 nm diameter lipid nanoparticles (LNC), and the ability of NFL-LNC to specifically target OL from newborn rat brain was assessed in vitro. Specific uptake of DiD-labeled NFL-LNC by OL characterized by CNP and myelin basic protein was observed by confocal microscopy, as well as DiD colocalization with NFL and with Rab5-a marker of early endosomes. Unvectorized LNC did not significantly penetrate OL and there was no uptake of NFL-LNC by astrocytes. Canonical maturation of OL which extended compacted myelin-like membranes was observed by transmission electron microscopy in cells grown up to 9 days with NFL-LNC. Endocytosis of NFL-LNC appeared to depend on several pathways, as demonstrated by inhibitors. In addition, vectorized NFL-LNC adsorbed on neurotrophin-3 (NT-3) potentiated the proremyelinating effects of NT-3 after demyelination by lysophosphatidyl choline, allowing noticeably decreasing NT-3 concentration. Our results if they were confirmed in vivo suggest that NFL-vectorized LNC appear safe and could be considered as putative carriers for specific drug delivery to OL in order to increase remyelination.

Dedifferentiation: inspiration for devising engineering strategies for regenerative medicine

Cell dedifferentiation is the process by which cells grow reversely from a partially or terminally differentiated stage to a less differentiated stage within their own lineage. This extraordinary phenomenon, observed in many physiological processes, inspires the possibility of developing new therapeutic approaches to regenerate damaged tissue and organs. Meanwhile, studies also indicate that dedifferentiation can cause pathological changes. In this review, we compile the literature describing recent advances in research on dedifferentiation, with an emphasis on tissue-specific findings, cellular mechanisms, and potential therapeutic applications from an engineering perspective. A critical understanding of such knowledge may provide fresh insights for designing new therapeutic strategies for regenerative medicine based on the principle of cell dedifferentiation.

Why have nanotechnologies been underutilized in the global uprising against the coronavirus pandemic?

Prior research on nanotechnologies in diagnostics, prevention and treatment of coronavirus infections is reviewed. Gold nanoparticles and semiconductor quantum dots in colorimetric and immunochromatographic assays, silica nanoparticles in the polymerase chain reaction and spike protein nanospheres as antigen carriers and adjuvants in vaccine formulations present notable examples in diagnostics and prevention, while uses of nanoparticles in coronavirus infection treatments have been merely sporadic. The current absence of antiviral therapeutics that specifically target human coronaviruses, including SARS-CoV-2, might be largely due to the underuse of nanotechnologies. Elucidating the interface between nanoparticles and coronaviruses is timely, but presents the only route to the rational design of precisely targeted therapeutics for coronavirus infections. Such a fundamental approach is also a viable prophylaxis against future pandemics of this type.

Promising Nanotechnology Approaches in Treatment of Autoimmune Diseases of Central Nervous System

Multiple sclerosis (MS) is a chronic, autoimmune, neurodegenerative disease of the central nervous system (CNS) that yields to neuronal axon damage, demyelization, and paralysis. Although several drugs were designed for the treatment of MS, with some of them being approved in the last few decades, the complete remission and the treatment of progressive forms still remain a matter of debate and a medical challenge. Nanotechnology provides a variety of promising therapeutic tools that can be applied for the treatment of MS, overcoming the barriers and the limitations of the already existing immunosuppressive and biological therapies. In the present review, we explore literature case studies on the development of drug delivery nanosystems for the targeted delivery of MS drugs in the pathological tissues of the CNS, providing high bioavailability and enhanced therapeutic efficiency, as well as nanosystems for the delivery of agents to facilitate efficient remyelination. Moreover, we present examples of tolerance-inducing nanocarriers, being used as promising vaccines for antigen-specific immunotherapy of MS. We emphasize on liposomes, as well as lipid- and polymer-based nanoparticles. Finally, we highlight the future perspectives given by the nanotechnology field toward the improvement of the current treatment of MS and its animal model, experimental autoimmune encephalomyelitis (EAE).

Current advances in the development of novel polymeric nanoparticles for the treatment of neurodegenerative diseases

Effective intervention is essential to combat the coming epidemic of neurodegenerative (ND) diseases. Nanomedicine can overcome restrictions of CNS delivery imposed by the blood-brain barrier, and thus be instrumental in preclinical discovery and therapeutic intervention of ND diseases. Polymeric nanoparticles (PNPs) have shown great potential and versatility to encapsulate several compounds simultaneously in controlled drug-delivery systems and target them to the deepest brain regions. Here, we critically review recent advances in the development of drugs incorporated into PNPs and summarize the molecular changes and functional effects achieved in preclinical models of the most common ND disorders. We also briefly discuss the many challenges remaining to translate these findings and technological advances successfully to current clinical settings.

Impact of IFN-β and LIF overexpression on human adipose-derived stem cells properties

Adipose-derived stem cells (ADSCs) are a subset of mesenchymal stem cells that their therapeutic effects in various diseases make them an interesting tool in cell therapy. In the current study, we aimed to overexpress interferon-β (IFN-β) and leukemia inhibitory factor (LIF) cytokines in human ADSCs to evaluate the impact of this overexpression on human ADSCs properties. Here, we designed a construct containing IFN-β and LIF and then, transduced human adipose-derived stem cells (hADSCs) by this construct via a lentiviral vector (PCDH-513B). We assessed the ability of long-term expression of the transgene in transduced cells by western blot analysis and enzyme-linked immunosorbent assay techniques on Days 15, 45, and 75 after transduction. For the evaluation of stem cell properties, flow cytometry and differentiation assays were performed. Finally, the MTT assay was done to assess the proliferation of transduced cells compares to controls. Our results showed high-efficiency transduction with highest expression rates on Day 75 after transduction which were 70 pg/ml for IFN-β and 77.9 pg/ml for LIF in comparison with 25.60 pg/ml and 27.63 pg/ml, respectively, in untransduced cells (p = .0001). Also, transduced cells expressed a high level of ADSCs surface markers and successfully differentiated into adipocytes, chondrocytes, neural cells, and osteocytes besides the preservation rate of proliferation near untreated cells (p = .88). All in all, we successfully constructed an hADSC population stably overexpressed IFN-β and LIF cytokines. Considering the IFN-β and LIF anti-inflammatory and neuroprotective effects as well as immune-regulatory properties of hADSCs, the obtained cells of this study could be subjected for further evaluations in experimental autoimmune encephalomyelitis mice model.