myelin-basic-protein and Alzheimer-Disease

Neurodegenerative diseases (NDD) are disorders characterized by the progressive loss of neurons affecting motor, sensory, and/or cognitive functions. The incidence of these diseases is increasing and has a great impact due to their high morbidity and mortality. Unfortunately, current therapeutic strategies only temporarily improve the patients' quality of life but are insufficient for completely alleviating the symptoms. An interaction between the immune system and the central nervous system (CNS) is widely associated with neuronal damage in NDD. Usually, immune cell infiltration has been identified with inflammation and is considered harmful to the injured CNS. However, the immune system has a crucial role in the protection and regeneration of the injured CNS. Nowadays, there is a consensus that deregulation of immune homeostasis may represent one of the key initial steps in NDD. Dr. Michal Schwartz originally conceived the concept of "protective autoimmunity" (PA) as a well-controlled peripheral inflammatory reaction after injury, essential for neuroprotection and regeneration. Several studies suggested that immunizing with a weaker version of the neural self-antigen would generate PA without degenerative autoimmunity. The development of CNS-related peptides with immunomodulatory neuroprotective effect led to important research to evaluate their use in chronic and acute NDD. In this review, we refer to the role of PA and the potential applications of active immunization as a therapeutic option for NDD treatment. In particular, we focus on the experimental and clinical promissory findings for CNS-related peptides with beneficial immunomodulatory effects.

Topics: Alzheimer Disease; Amyotrophic Lateral Sclerosis; Animals; Autoantigens; Autoimmunity; Glatiramer Acetate; Humans; Immunization, Passive; Immunologic Factors; Immunomodulation; Myelin Basic Protein; Nerve Regeneration; Neurodegenerative Diseases; Neuroprotection; Parkinson Disease; Peptide Fragments; Peptides; Proteostasis Deficiencies; Spinal Cord Injuries; Stroke

The accumulation of amyloid β-protein (Aβ) in the brain is a pathological feature of Alzheimer's disease (AD). Aβ peptides originate from amyloid precursor protein (APP). APP can be proteolytically cleaved through amyloidogenic or non-amyloidogenic pathways. The molecular effects on APP metabolism/processing may be influenced by myelin and the breakdown of myelin basic protein (MBP) in AD patients and mouse models of AD pathology.. We directly tested whether MBP can alter influence APP processing in MBP-/- mice, known as Shiverer (shi/shi) mice, in which no functional MBP is produced due to gene breakage from the middle of MBP exon ll.. A significant reduction of the cerebral sAPPα level in Shiverer (shi/shi) mice was found, although the levels of both total APP and sAPPβ remain unchanged. The reduction of sAPPα was considered to be due to the changes in the expression levels of a disintegrin and metalloproteinase-9 (ADAM9) catalysis and non-amyloid genic processing of APP in the absence of MBP because it binds to ADAM9. MBP -/- mice exhibited increased Aβ oligomer production.. These findings suggest that in the absence of MBP, there is a marked reduction of nonamyloidogenic APP processing to sAPPα, and targeting myelin of oligodendrocytes may be a novel therapy for the prevention and treatment of AD.

Topics: ADAM Proteins; Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Animals; Brain; Disease Models, Animal; Humans; Membrane Proteins; Mice; Myelin Basic Protein

Longstanding psychological stress has been associated with increased risk of neurodegenerative disorders, such as dementia and Alzheimer's disease. In a prospective population study of women (n = 81), we tested if midlife stress (mean age 49 years) was associated with late-life biomarkers of neurodegeneration in cerebrospinal fluid (CSF) (mean age 74 years) in linear regression models. It was found that women who report of stress at baseline (n = 20) had higher levels of CSF visinin-like protein-1 (VILIP-1) (age adjusted β = 0.113, p = 0.017) and CSF myelin basic protein (β = 0.060, p = 0.030) compared with women without midlife stress (n = 61). There was also a trend observed for higher CSF neurofilament light (β = 0.133, p = 0.056). In addition, longer periods of stress (i.e., stress at 2-3 midlife examinations) were associated with higher levels of CSF VILIP-1. The results suggest that longstanding stress might be associated with neurodegenerative processes in the brain, as CSF VILIP-1 is an unspecific marker for neuronal injury and CSF myelin basic protein reflects neuroaxonal demyelination.

Topics: Aged; Aging; Alzheimer Disease; Axons; Biomarkers; Brain; Dementia; Demyelinating Diseases; Female; Follow-Up Studies; Humans; Middle Aged; Myelin Basic Protein; Nerve Degeneration; Neurocalcin; Neurodegenerative Diseases; Neurofilament Proteins; Risk; Stress, Psychological; Time Factors

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Calcium; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Cell Differentiation; Cell Proliferation; Cell Survival; Cells, Cultured; Demyelinating Diseases; Integrin beta1; Myelin Basic Protein; Oligodendroglia; Organoids; Proto-Oncogene Proteins c-fyn; Rats; Rats, Sprague-Dawley; Signal Transduction

Topics: Aged; Aged, 80 and over; Aging; alpha-Synuclein; Alzheimer Disease; Amyloid beta-Protein Precursor; Animals; Brain; Cells, Cultured; Disease Models, Animal; Female; Humans; Mice, Inbred C57BL; Mice, Inbred DBA; Mice, Transgenic; Myelin Basic Protein; Myelin Sheath; Neurons; Parkinson Disease; Phospholipids; Presenilin-1

Microglia are resident immune cells in the central nervous system (CNS), which are essential for immune defence and critically contribute to neuronal functions during homeostasis. Until now, little is known about microglia biology in humans in part due to the lack of microglia-specific markers. We therefore investigated the expression of the purinergic receptor P2Y

Topics: Adolescent; Adult; Aged; Alzheimer Disease; Brain; Calbindins; Calcium-Binding Proteins; Cells, Cultured; Child, Preschool; Cytokines; DNA-Binding Proteins; Female; Fetus; Gene Expression Regulation, Developmental; Humans; Infant; Ki-67 Antigen; Microfilament Proteins; Microglia; Middle Aged; Multiple Sclerosis; Myelin Basic Protein; Receptors, Purinergic P2Y12; Young Adult

Brain autopsy and biomarker studies indicate that the pathology of Alzheimer's disease (AD) is initiated at least 10-20 years before clinical symptoms. This provides a window of opportunity to initiate preventive treatment. However, this emphasizes the necessity for biomarkers that identify individuals at risk for developing AD later in life. In this cross-sectional study, originating from three epidemiologic studies in Sweden (n=1428), the objective was to examine whether amyloid pathology, as determined by low cerebrospinal fluid (CSF) concentration of the 42 amino acid form of β-amyloid (Aβ42), is associated with biomarker evidence of other pathological changes in cognitively healthy elderly. A total of 129 patients were included and CSF levels of Aβ42, total tau, tau phosphorylated at threonine 181 (p-tau), neurogranin, VILIP-1, VEGF, FABP3, Aβ40, neurofilament light, MBP, orexin A, BDNF and YKL-40 were measured. Among these healthy elderly, 35.6% (N=46) had CSF Aβ42 levels below 530 pg ml

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Amyloid beta-Peptides; Apolipoprotein E4; Biomarkers; Brain-Derived Neurotrophic Factor; Chitinase-3-Like Protein 1; Cross-Sectional Studies; Fatty Acid Binding Protein 3; Female; Healthy Volunteers; Humans; Male; Myelin Basic Protein; Neurocalcin; Neurofilament Proteins; Neurogranin; Orexins; Peptide Fragments; Phosphoproteins; Sweden; tau Proteins; Vascular Endothelial Growth Factor A

T3D-959, a dual PPAR-δ/PPAR γ nuclear receptor agonist and former diabetes drug candidate, has been repositioned as an Alzheimer's disease (AD)-modifying therapy.. This study examines the effectiveness and mechanisms of T3D-959's therapeutic effects using in vivo and ex vivo rat models of sporadic AD.. A sporadic AD model was generated by intracerebral (i.c.) administration of streptozotocin (STZ). Control and i.c. STZ treated rats were gavaged with saline or T3D-959 (0.3 to 3.0 mg/kg/day) for 28 days. Spatial learning and memory were evaluated using the Morris water maze test. Frontal lobe slice cultures generated 24 hours after i.c. STZ or vehicle were used to study early effects of T3D-959 (0.5-1.0 μM) on viability and molecular markers of AD.. T3D-959 significantly improved spatial learning and memory in i.c STZ-treated rats. Mechanistically, T3D-959 significantly improved culture viability and brain morphology, reduced levels of oxidative stress and Aβ, and normalized expression of phospho-tau, choline acetyltransferase, and myelin-associated glycoprotein. Protective effects occurred even at the lowest tested dose of T3D-959.. Pre-clinical proof of concept has been demonstrated that T3D-959 can improve multiple pathologies of AD resulting in significant improvements in cognitive function and molecular and biochemical indices of neurodegeneration. These results support the theses that (1) effective disease modification in AD can be achieved by targeting relevant nuclear receptors, and (2) treating AD as a metabolic disease has the potential to be disease remedial. A Phase 2a trial of T3D-959 in mild-to-moderate AD patients has been initiated (ClinicalTrials.gov identifier NCT02560753).

Topics: Alzheimer Disease; Analysis of Variance; Animals; Animals, Newborn; Antibiotics, Antineoplastic; Antipsychotic Agents; Blood Glucose; Body Weight; Brain; Choline O-Acetyltransferase; Disease Models, Animal; Dose-Response Relationship, Drug; Glial Fibrillary Acidic Protein; Glucosephosphate Dehydrogenase; In Vitro Techniques; Maze Learning; Myelin Basic Protein; Neurotoxicity Syndromes; Organ Culture Techniques; PPAR delta; PPAR gamma; Rats; Rats, Long-Evans; Spatial Learning; Streptozocin

Dementia risk in women is higher than in men, but the molecular neuropathology of this gender difference remains poorly defined. In this study, we used unbiased, discovery-driven quantitative proteomics to assess the molecular basis of gender influences on risk of Alzheimer's disease with cerebrovascular disease (AD + CVD).. We detected modulation of several redox proteins in the temporal lobe of AD + CVD subjects, and we observed sex-specific alterations in the white matter (WM) and mitochondria proteomes of female patients. Functional proteomic analysis of AD + CVD brain tissues revealed increased citrullination of arginine and deamidation of glutamine residues of myelin basic protein (MBP) in female which impaired degradation of degenerated MBP and resulted in accumulation of non-functional MBP in WM. Female patients also displayed down-regulation of ATP sub-units and cytochromes, suggesting increased severity of mitochondria impairment in women.. Our study demonstrates that gender-linked modulation of white matter and mitochondria proteomes influences neuropathology of the temporal lobe in AD + CVD.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Amino Acids; Case-Control Studies; Cerebrovascular Disorders; Demography; Female; Humans; Male; Mitochondria; Myelin Basic Protein; Nerve Degeneration; Proteome; Sex Characteristics; Temporal Lobe; White Matter

Both multiple sclerosis (MS) and Alzheimer's disease (AD) are progressive neurological disorders with myelin injury and memory impairment. However, whether myelin impairment could cause AD-like neurological pathology remains unclear. To explore neurological pathology following myelin injury, we assessed cognitive function, the expression of myelin proteins, axonal transport-associated proteins, axonal structural proteins, synapse-associated proteins, tau and beta amyloid and the status of neurons, using the cuprizone mouse model of demyelination. We found the mild impairment of learning ability in cuprizone-fed mice and the decreased expression of myelin basic protein (MBP) in the hippocampus. And anti-LINGO-1 improved learning ability and partly restored MBP level. Furthermore, we also found kinesin light chain (KLC), neurofilament light chain (NFL) and neurofilament heavy chain (NF200) were declined in demyelinated hippocampus, which could be partly improved by treatment with anti-LINGO-1. However, we did not observe the increased expression of beta amyloid, hyperphosphorylation of tau and loss of neurons in demyelinated hippocampus. Our results suggest that demyelination might lead to the impairment of neuronal transport, but not cause increased level of hyperphosphorylated tau and beta amyloid. Our research demonstrates remyelination might be an effective pathway to recover the function of neuronal axons and cognition in MS.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Antibodies, Monoclonal; Axonal Transport; Axons; Cognition; Cuprizone; Demyelinating Diseases; Disease Models, Animal; Fluorescent Antibody Technique; Hippocampus; Humans; Kinesins; Male; Maze Learning; Membrane Proteins; Mice; Mice, Inbred C57BL; Microtubule-Associated Proteins; Myelin Basic Protein; Myelin Sheath; Nerve Tissue Proteins; Neurofilament Proteins; Phosphorylation; tau Proteins

Alzheimer's disease is a progressive neurodegenerative disorder that is characterized by extensive deposition of fibrillar amyloid-β (Aβ) in the brain. Previously, myelin basic protein (MBP) was identified to be a potent inhibitor to Aβ fibril formation, and this inhibitory activity was localized to the N-terminal residues 1-64, a fragment designated MBP1. Here, we show that the modest neuronal expression of a fusion protein of the biologically active MBP1 fragment and the enhanced green fluorescent protein (MBP1-EGFP) significantly improved the performance of spatial learning memory in Tg-5xFAD mice, a model of pathologic Aβ accumulation in brain. The levels of insoluble Aβ and fibrillar amyloid were significantly reduced in bigenic Tg-5xFAD/Tg-MBP1-EGFP mice. Quantitative stereological analysis revealed that the reduction in amyloid was because of a reduction in the size of fibrillar plaques rather than a decrease in plaque numbers. The current findings support previous studies showing that MBP1 inhibits Aβ fibril formation in vitro and demonstrate the ability of MBP1 to reduce Aβ pathology and improve behavioral performance.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Behavior; Brain; Disease Models, Animal; Mice, Transgenic; Myelin Basic Protein; Protein Aggregation, Pathological

The goal of this study was to show that myelin and axons in cortical gray matter are damaged in Alzheimer's disease (AD) brain. Superior temporal gyrus gray matter of AD patients (9 male, 14 female) was compared to cognitively normal controls (8 male, 7 female). Myelin basic protein (MBP) and a degraded myelin basic protein complex (dMBP) were quantified by Western blot. Brain sections were immunostained for MBP, dMBP, axonal neurofilament protein (NF), autophagy marker microtubule-associated proteins 1A/B light chain 3B precursor (LC3B), amyloid-β protein precursor (AβPP), and amyloid markers amyloid β1-42 (Aβ1-42) and FSB. Co-immunoprecipitation and mass spectroscopy evaluated interaction of AβPP/Aβ1-42 with MBP/dMBP. Evidence of axonal injury in AD cortex included appearance of AβPP in NF stained axons, and NF at margins of amyloid plaques. Evidence of myelin injury in AD cortex included (1) increased dMBP in AD gray matter compared to control (p < 0.001); (2) dMBP in AD neurons; and (3) increased LC3B that co-localized with MBP. Evidence of interaction of AβPP/Aβ1-42 with myelin or axonal components included (1) greater binding of dMBP with AβPP in AD brain; (2) MBP at the margins of amyloid plaques; (3) dMBP co-localized with Aβ1-42 in the core of amyloid plaques in AD brains; and (4) interactions between Aβ1-42 and MBP/dMBP by co-immunoprecipitation and mass spectrometry. We conclude that damaged axons may be a source of AβPP. dMBP, MBP, and NF associate with amyloid plaques and dMBP associates with AβPP and Aβ1-42. These molecules could be involved in formation of amyloid plaques.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Cerebral Cortex; Female; Humans; Immunoprecipitation; Male; Myelin Basic Protein; Neurofilament Proteins; Peptide Fragments; Plaque, Amyloid; Tandem Mass Spectrometry

Ischemia, white matter injury, and Alzheimer's disease (AD) pathologies often co-exist in aging brain. How one condition predisposes to, interacts with, or perhaps causes the others remains unclear.. To better understand the link between ischemia, white matter injury, and AD, adult rats were administered lipopolysaccharide (LPS) to serve as an inflammatory stimulus, and 24 h later subjected to 20-min focal cerebral ischemia (IS) followed by 30-min hypoxia (H).. Myelin and axonal damage, as well as amyloid-β (Aβ) and amyloid-β protein precursor (AβPP) deposition were examined by Western blot and immunocytochemistry following LPS/IS/H. Findings were compared to the 5XFAD mouse AD brain.. Myelin/axonal injury was observed bilaterally in cortex following LPS/IS/H, along with an increase in IL-1, granzyme B, and LPS. AβPP deposition was present in ischemic striatum in regions of myelin loss. Aβ(1-42) and AβPP were deposited in small foci in ischemic cortex that co-localized with myelin aggregates. In the 5XFAD mouse AD model, cortical amyloid plaques also co-localized with myelin aggregates.. LPS/IS/H produce myelin injury and plaque-like aggregates of myelin. AβPP and Aβ co-localize with these myelin aggregates.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Animals; Brain; Brain Ischemia; Disease Models, Animal; Inflammation; Lipopolysaccharides; Male; Mice; Mice, Transgenic; Myelin Basic Protein; Myelin Sheath; Peptide Fragments; Plaque, Amyloid; Rats; Rats, Sprague-Dawley

Delivering neurotherapeutics to target brain-associated diseases is a major challenge. Therefore, we investigated oral delivery of green fluorescence protein (GFP) or myelin basic protein (MBP) fused with the transmucosal carrier cholera toxin B subunit (CTB), expressed in chloroplasts (bioencapsulated within plant cells) to the brain and retinae of triple transgenic Alzheimer's disease (3×TgAD) mice, across the blood-brain barriers (BBB) and blood-retinal barriers (BRB). Human neuroblastoma cells internalized GFP when incubated with CTB-GFP but not with GFP alone. Oral delivery of CTB-MBP in healthy and 3×TgAD mice shows increased MBP levels in different regions of the brain, crossing intact BBB. Thioflavin S-stained amyloid plaque intensity was reduced up to 60% by CTB-MBP incubation with human AD and 3×TgAD mice brain sections ex vivo. Amyloid loads were reduced in vivo by 70% in hippocampus and cortex brain regions of 3×TgAD mice fed with bioencapsulated CTB-MBP, along with reduction in the ratio of insoluble amyloid β 42 (Aβ42) to soluble fractions. CTB-MBP oral delivery reduced Aβ42 accumulation in retinae and prevented loss of retinal ganglion cells in 3×TgAD mice. Lyophilization of leaves increased CTB-MBP concentration by 17-fold and stabilized it during long-term storage in capsules, facilitating low-cost oral delivery of therapeutic proteins across the BBB and BRB.

Topics: Administration, Oral; Alzheimer Disease; Animals; Blood-Brain Barrier; Blood-Retinal Barrier; Capsules; Cell Line, Tumor; Chloroplasts; Cholera Toxin; Disease Models, Animal; Female; Humans; In Vitro Techniques; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Myelin Basic Protein; Plant Leaves; Plaque, Amyloid; Recombinant Fusion Proteins

Myelin disruption is an important feature of Alzheimer's disease (AD) that contributes to impairment of neuronal circuitry and cognition. In this study we characterize myelin degradation in the brains of patients with Alzheimer's disease compared with normal aged controls.. Myelin from patients with AD (n=13) was compared to matched controls (n=6). Myelin degradation was examined by immunohistochemistry in frontal white matter (WM) for intact myelin basic protein (MBP), degraded MBP, the presence of myelin lipid and for PAS staining. The relationship of myelin degradation and axonal injury was also assessed.. Brains from patients with AD had significant loss of intact MBP, and an increase in degraded MBP in periventricular WM adjacent to a denuded ependymal layer. In regions of myelin degradation, vesicles were identified that stained positive for degraded MBP, myelin lipid, and neurofilament but not for intact MBP. Most vesicles stained for PAS, a corpora amylacea marker. The vesicles were significantly more abundant in the periventricular WM of AD patients compared to controls (44.5 ± 11.0 versus 1.7 ± 1.1, p=0.02).. In AD patients degraded MBP is associated in part with vesicles particularly in periventricular WM that is adjacent to areas of ependymal injury.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Brain; Cerebral Ventricles; Female; Humans; Male; Myelin Basic Protein; Myelin Sheath; Neurofilament Proteins

Topics: Alzheimer Disease; Aminopeptidases; Animals; Apolipoproteins E; Blood-Brain Barrier; Blood-Retinal Barrier; Chloroplasts; Cholera Toxin; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Female; Humans; Male; Myelin Basic Protein; Neuronal Ceroid-Lipofuscinoses; Peptides; Plaque, Amyloid; Serine Proteases; Tripeptidyl-Peptidase 1

White matter ischemia is difficult to quantify histologically. Myelin-associated glycoprotein (MAG) is highly susceptible to ischemia, being expressed only adaxonally, far from the oligodendrocyte cell body. Myelin-basic protein (MBP) and proteolipid protein (PLP) are expressed throughout the myelin sheath. We compared MAG, MBP, and PLP levels in parietal white matter homogenates from 17 vascular dementia (VaD), 49 Alzheimer's disease (AD), and 33 control brains, after assessing the post-mortem stability of these proteins. Small vessel disease (SVD) and cerebral amyloid angiopathy (CAA) severity had been assessed in paraffin sections. The concentration of MAG remained stable post-mortem, declined with increasing SVD, and was significantly lower in VaD than controls. The concentration of MBP fell progressively post-mortem, limiting its diagnostic utility in this context. Proteolipid protein was stable post-mortem and increased significantly with SVD severity. The MAG/PLP ratio declined significantly with SVD and CAA severity. The MAG and PLP levels and MAG/PLP did not differ significantly between AD and control brains. We validated the utility of MAG and MAG/PLP measurements on analysis of 74 frontal white matter samples from an Oxford cohort in which SVD had previously been scored. MAG concentration and the MAG/PLP ratio are useful post-mortem measures of ante-mortem white matter ischemia.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Biopsy; Brain Ischemia; Cohort Studies; Dementia, Vascular; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique, Direct; Humans; Middle Aged; Myelin Basic Protein; Myelin Proteolipid Protein; Myelin-Associated Glycoprotein; Parietal Lobe; Postmortem Changes; Protein Stability; Severity of Illness Index

Citrullination is a protein PTM of arginine residues catalyzed by peptidylarginine deiminase. Protein citrullination has been detected in the CNS and associated with a number of neurological diseases. However, identifying citrullinated proteins from complex mixtures and pinpointing citrullinated residues have been limited. Using RP LC and high-resolution MS, this study determined in vitro citrullination sites of glial fibrillary acid protein (GFAP), neurogranin (NRGN/RC3), and myelin basic protein (MBP) and in vivo sites in brain protein extract. Human GFAP has five endogenous citrullination sites, R30, R36, R270, R406, and R416, and MBP has 14 in vivo citrullination sites. Human NRGN/RC3 was found citrullinated at residue R68. The sequence of citrullinated peptides and citrullination sites were confirmed from peptides identified in trypsin, Lys-C, and Glu-C digests. The relative ratio of citrullination was estimated by simultaneous identification of citrullinated and unmodified peptides from Alzheimer's and control brain samples. The site occupancy of citrullination at the residue R68 of NRGN ranged from 1.6 to 9.5%. Compared to CID, higher-energy collisional dissociation (HCD) mainly produced protein backbone fragmentation for citrullinated peptides. CID-triggered HCD fragmentation is an optimal approach for the identification of citrullinated peptides in complex protein digests.

Topics: Alzheimer Disease; Animals; Brain; Cattle; Chromatography, Liquid; Citrulline; Glial Fibrillary Acidic Protein; Humans; Hydrolases; Mass Spectrometry; Myelin Basic Protein; Nervous System Diseases; Neurogranin; Protein-Arginine Deiminases

Abnormal accumulation of amyloid β-protein (Aβ) in the brain plays an important role in the pathogenesis \\of Alzheimer's disease (AD). Aβ monomers assemble into oligomers and fibrils that promote neuronal dysfunction. This assembly pathway is influenced by naturally occurring brain molecules, the Aβ chaperone proteins, which bind to Aβ and modulate its aggregation. Myelin basic protein (MBP) was previously identified as a novel Aβ chaperone protein and a potent inhibitor for Aβ fibril assembly in vitro.. In this study, we determined whether the absence of MBP would influence Aβ pathology in vivo by breeding MBP knockout mice (MBP-/-) with Tg-5xFAD mice, a model of AD-like parenchymal Aβ pathology.. Through biochemical and immunohistochemical experiments, we found that bigenic Tg-5xFAD/MBP-/- mice had a significant decrease of insoluble Aβ and parenchymal plaque deposition at an early age. The expression of transgene encoded human AβPP, the levels of C-terminal fragments generated during Aβ production and the intracellular Aβ were unaffected in the absence of MBP. Likewise, we did not find a significant difference in plasma Aβ or cerebrospinal fluid Aβ, suggesting these clearance routes were unaltered in bigenic Tg-5xFAD/MBP-/- mice. However, MBP-/- mice and bigenic Tg-5xFAD/MBP-/- mice exhibited elevated reactive astrocytes and activated microglia compared with Tg-5xFAD mice. The Aβ degrading enzyme matrix metalloproteinase 9 (MMP-9), which is expressed by activated glial cells, was significantly increased in the Tg-5xFAD/MBP-/- mice.. These findings indicate that the absence of MBP decreases Aβ deposition in transgenic mice and that this consequence may result from increased glial activation and expression of MMP-9, an Aβ degrading enzyme.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Brain; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Humans; Immunoblotting; Immunohistochemistry; Inflammation; Mice; Mice, Knockout; Mice, Transgenic; Myelin Basic Protein

The remarkable potentiality of bone marrow-derived mesenchymal stem cells (BM-MSCs) after transplantation to models of neurological disease and injury has been described. We have previously published data confirming the influence of BM-MSCs on β-amyloid (Aβ) deposition in an Alzheimer's disease (AD) mouse model. However, therapeutic approaches in neurological diseases such as AD, including those for BM-MSCs, are increasingly centered on the potential for prophylactic therapy in pro-dromal states where the underlying cause of the disease is apparent but functional deficits are not. In order to investigate whether BM-MSCs could have a beneficial effect in high-risk pre-dementia AD individuals, we treated young AD mice, at an age at which they display neuropathological, but not cognitive features of AD. Following a single intra-cerebral injection of BM-MSCs, interestingly, we found a significant decrease in the cerebral Aβ deposition compared with controls treated with PBS that was sustained up to 2 months post-injection. Expression of dynamin 1 and Synapsin 1, key pre-synaptic proteins associated with synaptic transmission, which are typically decreased in brains of AD patients, were considerably enhanced in the brains of AD mice treated with BM-MSCs and this response was sustained beyond 2 months. These data demonstrate that BM-MSCs produce an acute reduction in Aβ deposits and facilitate changes in key proteins required for synaptic transmission. These findings suggest that BM-MSC transplantation warrants further investigation as a potential therapy for early intervention in pro-dromal AD.

Topics: Age Factors; Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Animals; Brain; Disease Models, Animal; Female; Gene Expression Regulation; Humans; Male; Maze Learning; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mutation; Myelin Basic Protein; Nerve Tissue Proteins; Receptors, Glutamate; Synaptic Transmission

The measurement of proteins in cerebrospinal fluid (CSF) by enzyme-linked immunosorbent assays (ELISAs) is becoming increasingly important in the diagnosis of many neurodegenerative diseases such as Alzheimer's Disease. However, detection of proteins in these immunoassays can be hampered by confounding factors either present in the sample matrix or inherent to the protein of interest. These confounding factors may, for example, include protein aggregation or binding to other proteins resulting in epitope masking. Furthermore, the pH of CSF may vary considerably amongst different samples which may limit standardisation of CSF analysis. Pre-treatment of CSF to liberate epitopes or optimise conditions for antibody binding may enhance protein detection. In the current study we investigated whether CSF acidification followed by neutralisation (in short: AFBN) or neutralisation alone prior to measurement might improve the detection of a panel of brain-specific proteins. We demonstrate that the AFBN pre-treatment protocol for CSF significantly enhances the measurement of glutamine synthetase (GS) and myelin basic protein (MBP) in CSF but does not affect detection of glial fibrillary protein (GFAP), amyloid β 42 (Aβ₄₂), total tau (t-tau) or phosphorylated tau (p-tau). Neutralisation alone did not improve detection of any of the proteins tested. Based on our results, we suggest including the AFBN protocol in the evaluation of new biomarker development protocols to avoid confounders such as CSF pH or epitope-masking of the target protein.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Cerebrospinal Fluid; Enzyme-Linked Immunosorbent Assay; Glial Fibrillary Acidic Protein; Glutamate-Ammonia Ligase; Humans; Hydrogen-Ion Concentration; Myelin Basic Protein; Neurodegenerative Diseases; Neutralization Tests; Phosphorylation; Reproducibility of Results; Sensitivity and Specificity; tau Proteins

There is increasing evidence that in Lewy body-associated dementias (encompassing Parkinson's disease with dementia (PDD) and dementia with Lewy bodies (DLB)), the adaptive immune system is altered and the degenerative process includes glial cells in addition to neuronal structures. We therefore aimed to determine levels of autoantibodies against amyloid and glial-derived structures in these dementia types. Using a newly developed Enzyme-linked immunosorbent assay (ELISA), we measured levels of IgG autoantibodies against neuronal and glial structures in serum and cerebrospinal fluid of a total of 91 subjects (13 PDD, 14 DLB, 11 Alzheimer's disease (AD), 11 frontotemporal dementia (FTD), 11 vascular dementia patients (VaD), and 31 healthy controls). Autoantibody levels against α-synuclein, amyloid-β₄₂ (Aβ₄₂), myelin oligodendrocyte glycoprotein (MOG), myelin basic protein (MBP), and S100B were determined. In all groups, autoantibody levels were about three magnitudes higher in serum than in CSF. Serum autoantibody levels against α-synuclein, Aβ₄₂, MOG, MBP, and S100B were higher in PDD/DLB compared to tau-associated dementias (AD, FTD), VaD, and controls, respectively, with most of them reaching highly significant p-values. In cerebrospinal fluid (CSF), levels of antibodies against oligodendrocyte-derived antigens (MOG, MBP) were significantly increased in PDD/DLB. Increased levels of autoantibodies against both neuronal- and glial-derived antigens in serum and CSF of Lewy body-associated dementias indicate an altered activity of the adaptive immune system in these dementia types. The potential of neural-derived IgG autoantibodies as part of a biomarker panel for the diagnosis of Lewy body-associated dementias should be further evaluated.

Topics: Aged; alpha-Synuclein; Alzheimer Disease; Amyloid beta-Peptides; Autoantibodies; Enzyme-Linked Immunosorbent Assay; Female; Frontotemporal Dementia; Humans; Lewy Body Disease; Male; Myelin Basic Protein; Myelin Proteins; Myelin-Oligodendrocyte Glycoprotein; Nerve Growth Factors; Peptide Fragments; S100 Calcium Binding Protein beta Subunit; S100 Proteins

Alzheimer's disease (AD) and vascular dementia (VaD) are intertwined by mixed dementia (MD) harboring varying degrees of AD pathology in combination with cerebrovascular disease. The aim was to assess whether there is a difference in the cerebrospinal fluid (CSF) profile, of selected proteins, between patients with VaD and MD with subcortical vascular disease (SVD), AD, and healthy controls that could contribute in the separation of the groups. The study included 30 controls, 26 SVD patients (9 VaD and 17 MD) and 30 AD patients. The protein panel included total tau (T-tau), hyperphosphorylated tau 181 (P-tau(181)), amyloid β 1-42 (Aβ(1-42)), neurofilament light (NF-L), myelin basic protein (MBP), heart fatty acid binding protein (H-FABP), matrix metalloproteinases (MMP-1, -2, -3, -9, and -10), and tissue inhibitors of metalloproteinases (TIMP-1 and -2). Immunochemical methods were utilized for quantification of the proteins in CSF and data analysis was performed with a multivariate discriminant algorithm. The concentrations of MBP, TIMP-1, P-tau(181), NF-L, T-tau, MMP-9, Aβ(1-42), and MMP-2 contributed the most to the separation between SVD and AD, with a sensitivity of 89% and a specificity of 90% (AUC = 0.92). MBP and NF-L performed the best in discriminating SVD from controls, while T-tau and Aβ(1-42) contributed the most in segregating AD from controls. The CSF biomarkers reflecting AD pathology (T-tau, P-tau(181), and Aβ(1-42)), white matter lesions (NF-L and MBP) and matrix remodeling (MMP-9 and TIMP-1) perform well in differentiating between SVD and AD patients.

Topics: Aged; Alzheimer Disease; Biomarkers; Cerebral Cortex; Dementia, Vascular; Female; Humans; Male; Matrix Metalloproteinase 9; Middle Aged; Myelin Basic Protein; Neurofilament Proteins; Phosphorylation; tau Proteins; Tissue Inhibitor of Metalloproteinase-1

Although significant effects of interferon-gamma (IFN-gamma) on glial cells are well documented, information on the expression level and localization of glial IFN-gamma receptors (IFN-gamma-R) in the human central nervous system (CNS) is sparse. To examine the glial expression of IFN-gamma-R in the human CNS, immunohistochemistry and quantitative analyses were performed on Alzheimer disease hippocampus, Parkinson disease substantia nigra, amyotrophic lateral sclerosis spinal cord and corresponding areas from non-neurological cases. Almost all IFN-gamma-R-positive (IFN-gamma-R(+)) cells corresponded to GFAP-positive (GFAP(+)) astrocytes, while none of IFN-gamma-R(+) cells corresponded to IBA1-positive (IBA1(+)) microglia or MBP-positive (MBP(+)) oligodendrocytes in these neurological cases. We observed a similar pattern of glial IFN-gamma-R expression in non-neurological cases. Also, we quantitatively analyzed the IFN-gamma-R expression by cultured human glial cells using immunocytochemistry and reverse transcription polymerase chain reaction (RT-PCR). In contrast to in vivo results, almost all IFN-gamma-R(+) cells were IBA1(+) in microglial cultures, GFAP(+) in astrocytic cultures and MBP(+) in oligodendrocytic cultures. Moreover, no significant difference in IFN-gamma-R mRNA expression was found for these glial cell types by RT-PCR. These results suggest that the microglial and oligodendrocytic expression levels of IFN-gamma-R are much lower than the astrocytic expression levels in the human CNS in vivo, whereas all three types of glial cells constitutively express IFN-gamma-R when cultured in vitro.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Amyotrophic Lateral Sclerosis; Brain; Calcium-Binding Proteins; Cells, Cultured; DNA-Binding Proteins; Female; Gene Expression Regulation; Glial Fibrillary Acidic Protein; Humans; Interferon gamma Receptor; Male; Microfilament Proteins; Middle Aged; Myelin Basic Protein; Neuroglia; Parkinson Disease; Receptors, Interferon; Spinal Cord

The deposition of amyloid beta-protein (Abeta) fibrils into plaques within the brain parenchyma and along cerebral blood vessels is a hallmark of Alzheimer's disease. Abeta peptides are produced through the successive cleavage of the Abeta precursor protein by beta- and gamma-secretase, producing peptides between 39 and 43 amino acids in length. The most common of these are Abeta40 (the most abundant) and Abeta42. Abeta42 is more fibrillogenic than Abeta40 and has been implicated in early Abeta plaque deposition. Our previous studies determined that myelin basic protein (MBP) was capable of inhibiting fibril formation of a highly fibrillogenic Abeta peptide containing both E22Q (Dutch) and D23N (Iowa) mutations associated with familial forms of cerebral amyloid angiopathy [Hoos, M. D., et al. (2007) J. Biol. Chem. 282, 9952-9961]. In this study, we show through a combination of biochemical and ultrastructural techniques that MBP is also capable of inhibiting the beta-sheet fibrillar assembly of the normal Abeta42 peptide. These findings suggest that MBP may play a role in regulating the deposition of Abeta42 and thereby also may regulate the early formation of amyloid plaques in Alzheimer's disease.

Topics: Alzheimer Disease; Amino Acid Substitution; Amyloid beta-Peptides; Humans; Microscopy, Atomic Force; Microscopy, Electron, Transmission; Myelin Basic Protein; Peptide Fragments; Plaque, Amyloid; Protein Binding; Protein Structure, Secondary

The progressive accumulation of beta-amyloid (Abeta) in senile plaques and in the cerebral vasculature is the hallmark of Alzheimer disease and related disorders. Impaired clearance of Abeta from the brain likely contributes to the prevalent sporadic form of Alzheimer disease. Several major pathways for Abeta clearance include receptor-mediated cellular uptake, blood-brain barrier transport, and direct proteolytic degradation. Myelin basic protein (MBP) is the major structural protein component of myelin and plays a functional role in the formation and maintenance of the myelin sheath. MBP possesses endogenous serine proteinase activity and can undergo autocatalytic cleavage liberating distinct fragments. Recently, we showed that MBP binds Abeta and inhibits Abeta fibril formation (Hoos, M. D., Ahmed, M., Smith, S. O., and Van Nostrand, W. E. (2007) J. Biol. Chem. 282, 9952-9961; Hoos, M. D., Ahmed, M., Smith, S. O., and Van Nostrand, W. E. (2009) Biochemistry 48, 4720-4727). Here we show that Abeta40 and Abeta42 peptides are degraded by purified human brain MBP and recombinant human MBP, but not an MBP fragment that lacks autolytic activity. MBP-mediated Abeta degradation is inhibited by serine proteinase inhibitors. Similarly, Cos-1 cells expressing MBP degrade exogenous Abeta40 and Abeta42. In addition, we demonstrate that purified MBP also degrades assembled fibrillar Abeta in vitro. Mass spectrometry analysis identified distinct degradation products generated from Abeta digestion by MBP. Lastly, we demonstrate in situ that purified MBP can degrade parenchymal amyloid plaques as well as cerebral vascular amyloid that form in brain tissue of Abeta precursor protein transgenic mice. Together, these findings indicate that purified MBP possesses Abeta degrading activity in vitro.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Brain; Chlorocebus aethiops; COS Cells; Humans; Mice; Mice, Transgenic; Myelin Basic Protein; Peptide Fragments; Protein Isoforms; Recombinant Proteins

Myelin-associated proteins are involved in the formation and stabilization of myelin sheaths. In addition, they prevent axon regeneration and plasticity in the adult brain. Recent evidence suggests that the expression of certain myelin-associated proteins (e.g. Nogo-A) can be regulated by synaptic activity or by over-expression after neural lesions in brain syndromes such as temporal lobe epilepsy. However, no studies on Alzheimer disease (AD) have been reported in which cell loss and significant synaptic reorganization occurs. In the present study, we analyze in detail the expression of Nogo-A in the hippocampal formation in normal human aging and in AD. Our results indicate that Nogo-A is expressed by oligodendrocytes and neurons in the aged hippocampal formation. In addition, both granule cells and mossy fiber connections are also labeled in the old-aged hippocampi. Interestingly, Nogo-A is over-expressed by hippocampal neurons in AD and is associated with beta-amyloid deposits in senile plaques. Taken together, our results reinforce the hypothesis that Reticulon proteins such as Nogo-A participate in the neuronal responses stemming from hippocampal formation during senescence, and particularly in AD. These findings also indicate that Reticulon proteins could be considered as new putative drug targets in therapies of neurodegenerative disorders.

Topics: Adult; Aged; Aged, 80 and over; Aging; Alzheimer Disease; Amyloid beta-Peptides; Antibodies; Blotting, Western; Female; Gene Expression; Glial Fibrillary Acidic Protein; Hippocampus; Humans; Immunohistochemistry; Immunoprecipitation; Male; Middle Aged; Myelin Basic Protein; Myelin Proteins; Neurons; Nogo Proteins; Phosphopyruvate Hydratase; Postmortem Changes; Recoverin

The accumulation of amyloid beta (Abeta)-peptides and their collection in fibrillar plaques in the human brain are believed to be responsible for Alzheimer's disease. The major neuron killers in the Alzheimer brain include proinflammatory cytokines and NO made by NOS-2 (inducible nitric oxide synthase-2). We have determined the effect of a soluble Abeta peptide, Abeta(1-40), on the expression of NOS-2 in astrocytes using a novel model system consisting of pure cultures of cells from adult human brains that, after the first three passages in vitro, become stably locked into the normal astrocytic phenotype like their counterparts in the adult human brain. Abeta(1-40) alone stimulated quiescent astrocytes to start expressing functional NOS-2 and dumping NO into the culture medium during the next 4 days. But adding three of the proinflammatory cytokines commonly produced in the Alzheimer brain--IFN-gamma, IL-1beta, and TNF-alpha--along with Abeta(1-40) more than trebled NOS-2 expression and doubled NO production. In view of the possibility of myelin breakdown in the Alzheimer brain, we also tested the capability of myelin basic protein (MBP) to stimulate NO production using human astrocytes. We found that MBP mimicked the ability of Abeta(1-40) to induce cells to release NO and adding the cytokine triad along with MBP more than doubled NO production and release. Thus, it appears that Abeta peptides and MBP can join forces with proinflammatory cytokines to enhance the NO-mediated killing of neurons in the Alzheimer brain.

Topics: Adult; Alzheimer Disease; Amyloid beta-Peptides; Astrocytes; Cells, Cultured; Cytokines; Drug Synergism; Humans; Myelin Basic Protein; Nitric Oxide; Peptide Fragments

The structural substrates for age-associated cognitive and motor slowing are not known, but age-related white matter changes, such as ubiquitin (UBQ)-immunoreactive granular degeneration of myelin, might contribute to this slowing. To address this hypothesis we measured immunoreactivity for UBQ and myelin basic protein (MBP) in frontal white matter of age-, sex- and postmortem interval-matched cases with no cognitive impairment (NCI; N=12), mild cognitive impairment (MCI; N=14) and Alzheimer disease (AD; N=12). There were no significant correlations between UBQ in white matter and cognitive measures, but MBP was significantly lower in AD compared with NCI and MCI. MBP correlated with overall cognition as assessed by neuropsychological summary scores, as well as with timed cognitive tests and those that reflect frontal functions. An age-related decrease in MBP immunoreactivity was detected in NCI cases (r=0.71). These results support the hypothesis that white matter pathology may contribute to age-associated decline in cognition.

Topics: Aged; Aged, 80 and over; Aging; Alzheimer Disease; Blotting, Western; Chi-Square Distribution; Cognition Disorders; Female; Frontal Lobe; Humans; Immunoblotting; Immunohistochemistry; Male; Myelin Basic Protein; Neurologic Examination; Neuropsychological Tests; Statistics, Nonparametric; Ubiquitin

Relative to the gray matter, there is a paucity of information regarding white matter biochemical alterations and their contribution to Alzheimer's disease (AD). Biochemical analyses of AD white matter combining size-exclusion, normal phase, and gas chromatography, immunoassays, and Western blotting revealed increased quantities of Abeta40 and Abeta42 in AD white matter accompanied by significant decreases in the amounts of myelin basic protein, myelin proteolipid protein, and 2',3'-cyclic nucleotide 3'-phosphodiesterase. In addition, the AD white matter cholesterol levels were significantly decreased while total fatty acid content was increased. In some instances, these white matter biochemical alterations were correlated with patient apolipoprotein E genotype, Braak stage, and gender. Our observations suggest that extensive white matter axonal demyelination underlies Alzheimer's pathology, resulting in loss of capacitance and serious disturbances in nerve conduction, severely damaging brain function. These white matter alterations undoubtedly contribute to AD pathogenesis and may represent the combined effects of neuronal degeneration, microgliosis, oligodendrocyte injury, microcirculatory disease, and interstitial fluid stasis. To accurately assess the success of future therapeutic interventions, it is necessary to have a complete appreciation of the full scope and extent of AD pathology.

Topics: 2',3'-Cyclic Nucleotide 3'-Phosphodiesterase; Aged; Aged, 80 and over; Aging; Alzheimer Disease; Amyloid beta-Peptides; Cerebral Cortex; Cholesterol; Demyelinating Diseases; Fatty Acids; Female; Humans; Male; Middle Aged; Myelin Basic Protein; Myelin Proteins; Myelin Proteolipid Protein; Myelin Sheath; Oligodendroglia; Peptide Fragments; Phosphoric Diester Hydrolases

Topics: Adult; Aged; Aged, 80 and over; Alzheimer Disease; Autoantibodies; Dementia, Multi-Infarct; Female; Humans; Male; Middle Aged; Myelin Basic Protein

The expression of encephalitogenic peptide (EP), a 68-86 amino acid sequence of guinea pig myelin basic protein (MBP), was investigated in autopsied brains with focal cerebral damage or with diffuse white matter (WM) lesions. EP immunoreactive fibers were distributed in parallel with fibers immunoreactive for amyloid protein precursor (APP), an indicator of WM damages. EP was expressed in the periphery of cerebral infarctions and hematoma in the acute and subacute stages, but was also distributed in diffuse WM lesions due to heterogeneous causes. These data indicate that EP epitopes are exposed specifically in ongoing WM damages, and that the destruction of myelin occurs sporadically in diffuse WM lesions of varying intensity.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Animals; Autopsy; Brain; Cerebral Hemorrhage; Cerebral Infarction; Cerebrovascular Circulation; Dementia; Guinea Pigs; Hematoma; Humans; Myelin Basic Protein; Myelin Sheath; Nerve Fibers; Peptide Fragments

Several studies point to the importance of peptides and proteolysis in Alzheimer's disease (AD). Because of its ability to study small proteins and peptides, reverse-phase HPLC was employed to study these species in AD. Cerebellum was chosen for these initial studies because it does not show significant neuronal loss but does show some pathology in AD. Examination of over 600 peptide peaks per case revealed 15 that were elevated in AD. Nine were fragments of hemoglobin, and the remainder included two species of calmodulin, two of myelin basic protein, and one each of 67 kDa neurofilament protein and PEP-19. The cleavage sites on hemoglobin were after hydrophobic residues and immunolocalization was seen preferentially around blood vessel walls and granule cells. The elevation of the non-serum-derived peptides was characteristic of general metabolic changes that occurred in AD cerebellum, and the presence of elevated hemoglobin polypeptides indicated either possible disruption of the blood-brain barrier or selective evasion of it by peptidaceous products. Further studies are required to establish whether hemoglobin fragments have a role in neurodegenerative processes such as AD.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Amino Acid Sequence; Animals; Calmodulin; Cerebellum; Chromatography, High Pressure Liquid; Hemoglobins; Humans; Molecular Sequence Data; Molecular Weight; Myelin Basic Protein; Nerve Tissue Proteins; Neurofilament Proteins; Peptide Fragments; Rabbits; Reference Values; Sequence Homology, Amino Acid; Trypsin

Based on a suspected pathological relationship of autoimmunity in Alzheimer's disease (AD), antibodies to myelin basic protein (MBP) were investigated in the sera of AD patients, healthy controls and disease controls. As detected by the protein-immunoblotting technique at a screening serum dilution of 1:400, sera from 16 of 18 (89%) AD patients were positive for antibodies to MBP. In contrast, sera from only 7 of 90 controls (healthy adults and elderlies, Parkinson's disease patients, mentally-retarded children and Down's syndrome patients) showed a positive reaction. This approximately 11-times higher incidence of antibodies to MBP in AD patients was statistically significant (P < or = 0.0001) and may indicate an autoimmune process in the pathophysiology of the disease.

Topics: Adult; Aged; Aged, 80 and over; Alzheimer Disease; Autoantibodies; Electrophoresis, Polyacrylamide Gel; Female; Humans; Immunoblotting; Male; Middle Aged; Myelin Basic Protein; Rosaniline Dyes

Myelin basic protein (MBP) consists of several components or charge isomers (C-1 through C-8) generated by one or a combination of posttranslational modifications. One of these, C-8, has been shown to contain citrulline (Cit) at defined sites formed by deimination of six arginyl residues. This unusual modification has allowed us to raise antibodies specific for this charge isomer only. To do this, a synthetic peptide, Gly-Cit-Cit-Cit-Cit, was coupled to keyhole limpet hemocyanin and injected into rabbits. The antibodies so generated reacted only with C-8 and not with any of the other charge isomers. A second antibody fraction was raised against the synthetic peptide ACitHGFLPCitHR naturally occurring between residues 24 and 33 of C-8 (all other charge isomers contain R instead of Cit at positions 25 and 31). These antibodies preferred C-8 but reacted with the other charge isomers, to the extent of approximately 25-30% of the reactivity shown with C-8. In studies with C-8 from multiple sclerosis (MS) MBP, much greater reactivity was obtained with these antibodies when compared with their reactivity with C-8 from normal MBP. Because the total number of Cit residues in C-8 from MS and normal MBP is the same, the difference in reactivity may be related to structural factors. The antibodies raised with the tetra-Cit peptide were reacted with three pairs of synthetic peptides: 24ARHGFLPRHR33 and ACitHGFLPCitHR; 120GQRPGFGYGGRAS132 and GQCitPGFGYGGCitAS; and 157GGRDSRSGSPMARR170 and GGCitDSRSGSPMACitR. They reacted only with the Cit-containing peptides in the order 157-170 greater than 120-130 greater than 24-33.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Alzheimer Disease; Antibodies; Brain; Electrochemistry; Enzyme-Linked Immunosorbent Assay; Humans; Huntington Disease; Isomerism; Multiple Sclerosis; Myelin Basic Protein; Parkinson Disease; Peptides; Reference Values

The glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), S100 protein (S100), gamma gamma-enolase and neurofilament proteins were determined in the CSF of neurological patients. In Alzheimer's disease (AD), the GFAP values were very often increased but this was not specific to this disease. In 2 cases of familial AD, increases in neurofilament protein were detected. The determination of autoantibodies against neurofilament proteins in blood showed rather low values in AD, although they were higher than in subacute sclerosing panencephalitis (SSPE) and Chagas' disease. Increases were observed in diseases not related to AD such as vascular disorders and Parkinson's disease.

Topics: Aging; Alzheimer Disease; Brain Chemistry; Chagas Disease; Glial Fibrillary Acidic Protein; Humans; Intermediate Filament Proteins; Myelin Basic Protein; Neurofilament Proteins; S100 Proteins; Subacute Sclerosing Panencephalitis

We previously reported a marked increase of a 20,000 molecular weight (MW) protein, P20, in some neuronal fractions and whole cortical homogenates isolated from affected cortex in Alzheimer disease; P20 comigrated electrophoretically with an unidentified, major 20,000 MW protein present in human neurofilament (NF) fractions. We now report that the 20,000 MW protein is a major constituent of rodent as well as human NF fractions and that it comigrates by one- and two-dimensional gel electrophoresis with purified myelin basic protein (MBP). Peptide mapping and staining with amido black confirmed the identity of the 20,000 MW protein of mammalian NF fractions as MBP. One- and two-dimensional gel electrophoresis of neuronal perikaryal fractions from human cortex indicated that the increased P20 protein in Alzheimer neuronal fractions comigrates with human MBP. Deliberate contamination of cortical samples with adjacent subcortical white matter (i.e., myelin) prior to neuronal separation did not result in an increase of P20 in the neuronal fraction. On the basis of these and additional experiments, we conclude that the increase of a 20,000 MW protein in neuronal fractions and whole homogenates from affected cortex in Alzheimer disease represents MBP of intracortical origin.

Topics: Alzheimer Disease; Animals; Cerebral Cortex; Cytoskeleton; Dementia; Electrophoresis, Polyacrylamide Gel; Humans; Mice; Molecular Weight; Myelin Basic Protein; Myelin Sheath; Neurons; Rats