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International Journal of Molecular... Jun 2024Alzheimer's disease (AD), the leading cause of dementia worldwide, remains a challenge due to its complex origin and degenerative character. The need for accurate...
Alzheimer's disease (AD), the leading cause of dementia worldwide, remains a challenge due to its complex origin and degenerative character. The need for accurate biomarkers and treatment targets hinders early identification and intervention. To fill this gap, we used a novel longitudinal proteome methodology to examine the temporal development of molecular alterations in the cortex of an intracerebroventricular streptozotocin (ICV-STZ)-induced AD mouse model for disease initiation and progression at one, three-, and six-weeks post-treatment. Week 1 revealed metabolic protein downregulation, such as Aldoa and Pgk1. Week 3 showed increased Synapsin-1, and week 6 showed cytoskeletal protein alterations like Vimentin. The biological pathways, upstream regulators, and functional effects of proteome alterations were dissected using advanced bioinformatics methods, including Ingenuity Pathway Analysis (IPA) and machine learning algorithms. We identified Mitochondrial Dysfunction, Synaptic Vesicle Pathway, and Neuroinflammation Signaling as disease-causing pathways. Huntington's Disease Signaling and Synaptogenesis Signaling were stimulated while Glutamate Receptor and Calcium Signaling were repressed. IPA also found molecular connections between PPARGC1B and AGT, which are involved in myelination and possible neoplastic processes, and MTOR and AR, which imply mechanistic involvements beyond neurodegeneration. These results help us comprehend AD's molecular foundation and demonstrate the promise of focused proteomic techniques to uncover new biomarkers and therapeutic targets for AD, enabling personalized medicine.
Topics: Animals; Alzheimer Disease; Disease Models, Animal; Proteomics; Mice; Proteome; Male; Signal Transduction; Biomarkers; Disease Progression
PubMed: 38928172
DOI: 10.3390/ijms25126469 -
International Journal of Molecular... Jun 2024The use of acellular nerve allografts (ANAs) to reconstruct long nerve gaps (>3 cm) is associated with limited axon regeneration. To understand why ANA length might...
Limited Nerve Regeneration across Acellular Nerve Allografts (ANAs) Coincides with Changes in Blood Vessel Morphology and the Development of a Pro-Inflammatory Microenvironment.
The use of acellular nerve allografts (ANAs) to reconstruct long nerve gaps (>3 cm) is associated with limited axon regeneration. To understand why ANA length might limit regeneration, we focused on identifying differences in the regenerative and vascular microenvironment that develop within ANAs based on their length. A rat sciatic nerve gap model was repaired with either short (2 cm) or long (4 cm) ANAs, and histomorphometry was used to measure myelinated axon regeneration and blood vessel morphology at various timepoints (2-, 4- and 8-weeks). Both groups demonstrated robust axonal regeneration within the proximal graft region, which continued across the mid-distal graft of short ANAs as time progressed. By 8 weeks, long ANAs had limited regeneration across the ANA and into the distal nerve (98 vs. 7583 axons in short ANAs). Interestingly, blood vessels within the mid-distal graft of long ANAs underwent morphological changes characteristic of an inflammatory pathology by 8 weeks post surgery. Gene expression analysis revealed an increased expression of pro-inflammatory cytokines within the mid-distal graft region of long vs. short ANAs, which coincided with pathological changes in blood vessels. Our data show evidence of limited axonal regeneration and the development of a pro-inflammatory environment within long ANAs.
Topics: Animals; Nerve Regeneration; Rats; Sciatic Nerve; Allografts; Axons; Male; Blood Vessels; Inflammation; Cellular Microenvironment; Transplantation, Homologous; Cytokines; Rats, Sprague-Dawley
PubMed: 38928119
DOI: 10.3390/ijms25126413 -
Genes Jun 2024Extracellular vesicles (EVs) are "micro-shuttles" that play a role as mediators of intercellular communication. Cells release EVs into the extracellular environment in... (Review)
Review
Extracellular vesicles (EVs) are "micro-shuttles" that play a role as mediators of intercellular communication. Cells release EVs into the extracellular environment in both physiological and pathological conditions and are involved in intercellular communication, due to their ability to transfer proteins, lipids, and nucleic acids, and in the modulation of the immune system and neuroinflammation. Because EVs can penetrate the blood-brain barrier and move from the central nervous system to the peripheral circulation, and vice versa, recent studies have shown a substantial role for EVs in several neurological diseases, including multiple sclerosis (MS). MS is a demyelinating disease where the main event is caused by T and B cells triggering an autoimmune reaction against myelin constituents. Recent research has elucidate the potential involvement of extracellular vesicles (EVs) in the pathophysiology of MS, although, to date, their potential role both as agents and therapeutic targets in MS is not fully defined. We present in this review a summary and comprehensive examination of EVs' involvement in the pathophysiology of multiple sclerosis, exploring their potential applications as biomarkers and indicators of therapy response.
Topics: Humans; Multiple Sclerosis; Extracellular Vesicles; Biomarkers; Animals; Blood-Brain Barrier
PubMed: 38927708
DOI: 10.3390/genes15060772 -
Biomedicines Jun 2024Nerve injury is a common condition that occurs as a result of trauma, iatrogenic injury, or long-lasting stimulation. Unlike the central nervous system (CNS), the... (Review)
Review
Nerve injury is a common condition that occurs as a result of trauma, iatrogenic injury, or long-lasting stimulation. Unlike the central nervous system (CNS), the peripheral nervous system (PNS) has a strong capacity for self-repair and regeneration. Peripheral nerve injury results in the degeneration of distal axons and myelin sheaths. Macrophages and Schwann cells (SCs) can phagocytose damaged cells. Wallerian degeneration (WD) makes the whole axon structure degenerate, creating a favorable regenerative environment for new axons. After nerve injury, macrophages, neutrophils and other cells are mobilized and recruited to the injury site to phagocytose necrotic cells and myelin debris. Pro-inflammatory and anti-inflammatory factors involved in the inflammatory response provide a favorable microenvironment for peripheral nerve regeneration and regulate the effects of inflammation on the body through relevant signaling pathways. Previously, inflammation was thought to be detrimental to the body, but further research has shown that appropriate inflammation promotes nerve regeneration, axon regeneration, and myelin formation. On the contrary, excessive inflammation can cause nerve tissue damage and pathological changes, and even lead to neurological diseases. Therefore, after nerve injury, various cells in the body interact with cytokines and chemokines to promote peripheral nerve repair and regeneration by inhibiting the negative effects of inflammation and harnessing the positive effects of inflammation in specific ways and at specific times. Understanding the interaction between neuroinflammation and nerve regeneration provides several therapeutic ideas to improve the inflammatory microenvironment and promote nerve regeneration.
PubMed: 38927464
DOI: 10.3390/biomedicines12061256 -
Biomedicines May 2024Experimental autoimmune encephalomyelitis (EAE) is a powerful model to study multiple sclerosis (MS). One of the approaches for EAE is to actively immunize with...
Mild Disease Course of Experimental Autoimmune Encephalomyelitis without Pertussis Toxin: Brain Transcriptome Analysis Reveals Similar Signaling to Active Lesions in Multiple Sclerosis.
Experimental autoimmune encephalomyelitis (EAE) is a powerful model to study multiple sclerosis (MS). One of the approaches for EAE is to actively immunize with myelin-derived peptides with immune adjuvants. One of the commonly used immune adjuvants is pertussis toxin (PTx), without which EAE disease is mild with relatively longer onset. However, pertussis toxin can also inhibit G protein-coupled receptor (GPCR) signaling so it can confound investigations into the role of GPCRs in EAE or therapies designed to target GPCRs. Since EAE via active immunization without PTx results in a relatively mild disease state, we wanted to confirm that appropriate signaling molecules for the disease were being induced in one target tissue (i.e., brain). RNA-Seq analysis of whole brain tissue demonstrated that the MS signaling pathway was strongly activated in symptomatic mice. In addition, there was activation of Th1 (IFN signaling), Th2 (IL-4 signaling), and Th17 (IL-17 signaling). In comparing canonical pathways from our mouse mild EAE brains with a human MS atlas, EAE shared the most pathways with active and inactive lesions. An advantage of this approach is that disease induction is slower to develop and results in modest clinical signs, which likely more closely mimic human disease onset.
PubMed: 38927422
DOI: 10.3390/biomedicines12061215 -
Nature Communications Jun 2024B cells and T cells collaborate in multiple sclerosis (MS) pathogenesis. IgH mice possess a B cell repertoire skewed to recognize myelin oligodendrocyte glycoprotein...
B cells and T cells collaborate in multiple sclerosis (MS) pathogenesis. IgH mice possess a B cell repertoire skewed to recognize myelin oligodendrocyte glycoprotein (MOG). Here, we show that upon immunization with the T cell-obligate autoantigen, MOG, IgH mice develop rapid and exacerbated experimental autoimmune encephalomyelitis (EAE) relative to wildtype (WT) counterparts, characterized by aggregation of T and B cells in the IgH meninges and by CD4 T helper 17 (Th17) cells in the CNS. Production of the Th17 maintenance factor IL-23 is observed from IgH CNS-infiltrating and meningeal B cells, and in vivo blockade of IL-23p19 attenuates disease severity in IgH mice. In the CNS parenchyma and dura mater of IgH mice, we observe an increased frequency of CD4PD-1CXCR5 T cells that share numerous characteristics with the recently described T peripheral helper (Tph) cell subset. Further, CNS-infiltrating B and Tph cells from IgH mice show increased reactive oxygen species (ROS) production. Meningeal inflammation, Tph-like cell accumulation in the CNS and B/Tph cell production of ROS were all reduced upon p19 blockade. Altogether, MOG-specific B cells promote autoimmune inflammation of the CNS parenchyma and meninges in an IL-23-dependent manner.
Topics: Animals; Encephalomyelitis, Autoimmune, Experimental; B-Lymphocytes; Myelin-Oligodendrocyte Glycoprotein; Mice; Autoimmunity; Interleukin-23; CD4-Positive T-Lymphocytes; Th17 Cells; Central Nervous System; Mice, Inbred C57BL; Female; Myelin Sheath; Meninges; Multiple Sclerosis
PubMed: 38926356
DOI: 10.1038/s41467-024-49259-0 -
Planta Medica Jun 2024Prolonged exposure to lead has been recognized as harmful to human health as it may cause neurotoxic effects including mitochondrial damage, apoptosis, excitotoxicity,...
Prolonged exposure to lead has been recognized as harmful to human health as it may cause neurotoxic effects including mitochondrial damage, apoptosis, excitotoxicity, and myelin formation alterations, among others. Numerous data have shown that consuming olive oil and its valuable components could reduce neurotoxicity and degenerative conditions. Olive oil is traditionally obtained from olive trees; this plant (Olea europaea L.) is an evergreen fruit tree. In this manuscript two extracts have been used and compared: the extract from the leaves of Olea europaea L., (OE), and the extract derived from OE but with a further sonication process (s-OE). Therefore, the objectives of this experimental work were as follows: 1) To generate an innovative extract; 2) To test both extracts on a model of neurotoxicity of human neurons induced following lead exposure; and 3) To study the mechanisms behind lead-induced neurotoxicity. The results showed that the mechanism involved in the neurotoxicity of lead included dysfunction of the cellular endoplasmic reticulum, which suffered oxidative damage. In addition, in all experiments s-OE was more effective than OE, having greater and better effects against lead-induced damage, and being dissolved in a smaller amount of EtOH that promotes its sustainability.
PubMed: 38925154
DOI: 10.1055/a-2353-1469 -
Neurology(R) Neuroimmunology &... Sep 2024Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a distinct CNS demyelinating disease. The rate of asymptomatic optic nerve enhancement on MRI...
BACKGROUND AND OBJECTIVES
Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a distinct CNS demyelinating disease. The rate of asymptomatic optic nerve enhancement on MRI has not been explored in patients with MOGAD. An improved understanding of this would guide clinical practice and assessment of treatment efficacy. We aimed to determine the frequency of asymptomatic optic nerve enhancement in MOGAD.
METHODS
This was a retrospective review of patients evaluated at Mayo Clinic with MOGAD between January 1, 2000, and August 1, 2021 (median follow-up 1.6 [range 1-19] years). MRI studies were reviewed by masked neuroradiologists. Scans performed within 30 days of ON attack were classified as attack scans. Images obtained for routine surveillance, before ON attack, or at the time of non-ON attack were classified as interattack scans.
RESULTS
Five hundred sixty-six MRIs (203 unique patients, 53% female) were included. Interattack MRIs represented 341 (60%) of the scans (median 36 days post-ON [range -1,032 to 6,001]). Of the interattack scans, 43 of 341 (13%), 30 unique patients, showed optic nerve enhancement. The enhancement was located at prior sites of ON in 35 of 43 (81%). Among the 8 patients with enhancement in new optic nerve areas, 6 had acute disseminated encephalomyelitis without an eye examination at the time of the MRI and 2 had preceding ON without imaging. Long-term visual outcomes showed no significant difference between those with and without asymptomatic enhancement, with improved visual acuity in most patients.
DISCUSSION
Asymptomatic optic nerve enhancement occurred in 13% of interattack MRIs, the majority in patients with prior ON and occurring at prior sites of optic nerve enhancement. New asymptomatic optic nerve enhancement in areas without prior ON was rare. These findings are important for understanding the natural history of MOGAD, the interpretation of symptoms or response to treatment, and the adjudication of attacks in clinical trials.
Topics: Humans; Female; Male; Adult; Myelin-Oligodendrocyte Glycoprotein; Retrospective Studies; Magnetic Resonance Imaging; Middle Aged; Young Adult; Optic Nerve; Adolescent; Aged; Child; Autoantibodies; Demyelinating Autoimmune Diseases, CNS; Child, Preschool; Asymptomatic Diseases; Aged, 80 and over
PubMed: 38924706
DOI: 10.1212/NXI.0000000000200277 -
Current Issues in Molecular Biology Jun 2024Multiple sclerosis (MS) is a chronic autoimmune demyelinating disease of the central nervous system, the etiology of which is still unclear. Its hallmarks are... (Review)
Review
Multiple sclerosis (MS) is a chronic autoimmune demyelinating disease of the central nervous system, the etiology of which is still unclear. Its hallmarks are inflammation and axonal damage. As a disease primarily impacting younger individuals, the social cost of MS is high. It has been proposed that environmental factors, smoking, and dietary habits acting on a genetic susceptibility play a role in MS. Recent studies indicate that diet can significantly influence the onset and progression of MS. This review delves into the impact of natural bioactive molecules on MS development and explores the dietary interventions that hold promise in managing the disease. Dietary patterns, including ketogenic and Mediterranean diets, are discussed. Theories about the potential mechanistic associations beneath the noted effects are also proposed. Several dietary components and patterns demonstrated the potential for a significant impact on MS. However, extensive prospective clinical trials are necessary to fully understand the role of natural bioactive molecules as disease modifiers in MS.
PubMed: 38921006
DOI: 10.3390/cimb46060335 -
Cells Jun 2024Oligodendrocyte progenitor cells (OPCs) represent a subtype of glia, giving rise to oligodendrocytes, the myelin-forming cells in the central nervous system (CNS). While... (Review)
Review
Oligodendrocyte progenitor cells (OPCs) represent a subtype of glia, giving rise to oligodendrocytes, the myelin-forming cells in the central nervous system (CNS). While OPCs are highly proliferative during development, they become relatively quiescent during adulthood, when their fate is strictly influenced by the extracellular context. In traumatic injuries and chronic neurodegenerative conditions, including those of autoimmune origin, oligodendrocytes undergo apoptosis, and demyelination starts. Adult OPCs become immediately activated; they migrate at the lesion site and proliferate to replenish the damaged area, but their efficiency is hampered by the presence of a glial scar-a barrier mainly formed by reactive astrocytes, microglia and the deposition of inhibitory extracellular matrix components. If, on the one hand, a glial scar limits the lesion spreading, it also blocks tissue regeneration. Therapeutic strategies aimed at reducing astrocyte or microglia activation and shifting them toward a neuroprotective phenotype have been proposed, whereas the role of OPCs has been largely overlooked. In this review, we have considered the glial scar from the perspective of OPCs, analysing their behaviour when lesions originate and exploring the potential therapies aimed at sustaining OPCs to efficiently differentiate and promote remyelination.
Topics: Humans; Remyelination; Animals; Oligodendrocyte Precursor Cells; Cicatrix; Neuroglia; Oligodendroglia; Myelin Sheath; Cell Differentiation
PubMed: 38920654
DOI: 10.3390/cells13121024