Detection of myelin basic protein in cerebrospinal fluid

Pathogenesis and management of multiple sclerosis revisited

BACKGROUND

Multiple sclerosis is an autoimmune chronic inflammatory disease characterized by selective destruction of myelin in the CNS neurons (including optic nerve). It was first described in the 19th century and remained elusive owing to the disease's unique relapsing and remitting course. The widespread and debilitating prevalence of multiple sclerosis (MS) has prompted the development of various treatment modalities for its effective management.

METHODS AND OBJECTIVES

A literature review was conducted using the electronic databases PubMed and Google Scholar. The main objective of the review was to compile the advances in pathogenesis, classifications, and evolving treatment modalities for MS.

RESULTS

The understanding of the pathogenesis of MS and the potential drug targets for its precise treatment has evolved significantly over the past decade. The experimental developments are also motivating and present a big change coming up in the next 5 years. Numerous disease-modifying therapies (DMTs) have revolutionized the management of MS: interferon (IFN) preparations, monoclonal antibodies-natalizumab and ocrelizumab, immunomodulatory agents-glatiramer acetate, sphingosine 1-phosphate receptor 1 (S1PR1) modulators (Siponimod) and teriflunomide. The traditional parenteral drugs are now available as oral formulations improving patient acceptability. Repurposing various agents used for related diseases may reinforce the drug reserve to manage MS and are under trials. Although at a nascent phase, strategies to enhance re-myelination by stimulating oligodendrocytes are fascinating and hold promise for better outcomes in patients with MS.

CONCLUSIONS

The recent past has seen staggering inclusions to the management of multiple sclerosis catalyzing a significant turnabout in our approach to diagnosis, treatment, and prognosis. Since the advent of DMTs various other oral and injectable agents have been approved. The advances in MS therapeutics and diagnostics have laid the ground for further research and development to enhance the quality of life of afflicted patients.

Cerebrolysin Attenuates Exacerbation of Neuropathic Pain, Blood-spinal Cord Barrier Breakdown and Cord Pathology Following Chronic Intoxication of Engineered Ag, Cu or Al (50-60 nm) Nanoparticles

Neuropathic pain is associated with abnormal sensations and/or pain induced by non-painful stimuli, i.e., allodynia causing burning or cold sensation, pinching of pins and needles like feeling, numbness, aching or itching. However, no suitable therapy exists to treat these pain syndromes. Our laboratory explored novel potential therapeutic strategies using a suitable composition of neurotrophic factors and active peptide fragments-Cerebrolysin (Ever Neuro Pharma, Austria) in alleviating neuropathic pain induced spinal cord pathology in a rat model. Neuropathic pain was produced by constrictions of L-5 spinal sensory nerves for 2-10 weeks period. In one group of rats cerebrolysin (2.5 or 5 ml/kg, i.v.) was administered once daily after 2 weeks until sacrifice (4, 8 and 10 weeks). Ag, Cu and Al NPs (50 mg/kg, i.p.) were delivered once daily for 1 week. Pain assessment using mechanical (Von Frey) or thermal (Hot-Plate) nociceptive showed hyperalgesia from 2 weeks until 10 weeks progressively that was exacerbated following Ag, Cu and Al NPs intoxication in nerve lesioned groups. Leakage of Evans blue and radioiodine across the blood-spinal cord barrier (BSCB) is seen from 4 to 10 weeks in the rostral and caudal cord segments associated with edema formation and cell injury. Immunohistochemistry of albumin and GFAP exhibited a close parallelism with BSCB leakage that was aggravated by NPs following nerve lesion. Light microscopy using Nissl stain exhibited profound neuronal damages in the cord. Transmission electron microcopy (TEM) show myelin vesiculation and synaptic damages in the cord that were exacerbated following NPs intoxication. Using ELISA spinal tissue exhibited increased albumin, glial fibrillary acidic protein (GFAP), myelin basic protein (MBP) and heat shock protein (HSP 72kD) upregulation together with cytokines TNF-α, IL-4, IL-6, IL-10 levels in nerve lesion that was exacerbated following NPs intoxication. Cerebrolysin treatment significantly reduced hyperalgesia and attenuated BSCB disruption, edema formation and cellular changes in nerve lesioned group. The levels of cytokines were also restored near normal levels with cerebrolysin treatment. Albumin, GFAP, MABP and HSP were also reduced in cerebrolysin treated group and thwarted neuronal damages, myelin vesiculation and cell injuries. These neuroprotective effects of cerebrolysin with higher doses were also effective in nerve lesioned rats with NPs intoxication. These observations suggest that cerebrolysin actively protects spinal cord pathology and hyperalgesia following nerve lesion and its exacerbation with metal NPs, not reported earlier.

Nanowired Delivery of Cerebrolysin Together with Antibodies to Amyloid Beta Peptide, Phosphorylated Tau, and Tumor Necrosis Factor Alpha Induces Superior Neuroprotection in Alzheimer's Disease Brain Pathology Exacerbated by Sleep Deprivation

Sleep deprivation induces amyloid beta peptide and phosphorylated tau deposits in the brain and cerebrospinal fluid together with altered serotonin metabolism. Thus, it is likely that sleep deprivation is one of the predisposing factors in precipitating Alzheimer's disease (AD) brain pathology. Our previous studies indicate significant brain pathology following sleep deprivation or AD. Keeping these views in consideration in this review, nanodelivery of monoclonal antibodies to amyloid beta peptide (AβP), phosphorylated tau (p-tau), and tumor necrosis factor alpha (TNF-α) in sleep deprivation-induced AD is discussed based on our own investigations. Our results suggest that nanowired delivery of monoclonal antibodies to AβP with p-tau and TNF-α induces superior neuroprotection in AD caused by sleep deprivation, not reported earlier.

Activating SIRT-1 Signalling with the Mitochondrial-CoQ10 Activator Solanesol Improves Neurobehavioral and Neurochemical Defects in Ouabain-Induced Experimental Model of Bipolar Disorder

Bipolar disorder (BD) is a chronic mental illness characterized by mood fluctuations that range from depressive lows to manic highs. Several studies have linked the downregulation of SIRT-1 (silent mating type information regulation-2 homologs) signaling to the onset of BD and other neurological dysfunctions. This research aimed to look into the neuroprotective potential of Solanesol (SNL) in rats given ICV-Ouabain injections, focusing on its effect on SIRT-1 signaling activation in the brain. Ouabain, found in hypothalamic and medullary neurons, is an endogenous inhibitor of brain Na⁺/K⁺ ATPase. The inhibition of brain Na⁺/K⁺ ATPase by Ouabain may also result in changes in neurotransmission within the central nervous system. SNL is a Solanaceae family active phytoconstituent produced from the plant Nicotiana tabacum. SNL is used as a precursor for the production of CoQ10 (Coenzyme Q10), a powerful antioxidant and neuroprotective compound. In the current study, lithium (Li), an important mood stabilizer drug, was used as a control. This study looked at the neuroprotective potential of SNL at dosages of 40 and 80 mg/kg in ICV-OUA injections that caused BD-like neurobehavioral and neurochemical defects in Wistar rats. Wistar rats were placed into eight groups (n = 6) and administered 1 mM/0.5 µL ICV-OUA injections for three days. Neurochemical assessments were done in rat brain homogenates, CSF, and blood plasma samples at the end of the experiment protocol schedule. Long-term SNL and lithium administration have been shown to decrease the number of rearing and crossings and reduce time spent in the center, locomotor activities, and immobility time. Solansesol treatment gradually raises the amount of Na⁺/K⁺ ATPase, limiting the severity of behavioural symptoms. These findings also revealed that SNL increases the levels of SIRT-1 in CSF, blood plasma, and brain homogenate samples. Moreover, in rat brain homogenates and blood plasma samples, SNL modulates apoptotic markers such as Caspase-3, Bax (pro-apoptotic), and Bcl-2 (anti-apoptotic). Mitochondrial-ETC complex enzymes, including complex-I, II, IV, V, and CoQ10, were also restored following long-term SNL treatment. Furthermore, SNL lowered inflammatory cytokines (TNF-α, IL-1β) levels while restoring neurotransmitter levels (serotonin, dopamine, glutamate, and acetylcholine) and decreasing oxidative stress markers. Histological examinations also validated Solanesol’s protective effect. As a result, our findings suggest that SNL, as a SIRT-1 signalling activator, may be a promising therapeutic approach for BD-like neurological dysfunctions.

Heroin Relapse "Strikes a Nerve": A Rare Case of Drug-Induced Acute Myelopathy

Opioid addiction is a major public health problem. Through a commitment to individualized treatment plans meant to help patients meet personal goals, behavioral therapy can encourage abstinence and help prevent relapses that can have debilitating consequences.

This case describes a 31-year-old male with heroin relapse who presented with flaccid quadriparesis as well as loss of sensation below the T2-3 spinal level, loss of rectal tone, and urinary retention. A urine drug screen (UDS) was positive for opiates and amphetamines. Autoimmune serologies were negative. Cerebrospinal fluid (CSF) analysis was negative for any acute ongoing infectious process. Magnetic resonance imaging (MRIs) of the cervical and thoracic spine showed increased intramedullary signals with spinal cord expansion from C2-T2, indicating acute transverse myelitis. Upon completion of the aforementioned work-up, idiopathic transverse myelopathy (TM) was diagnosed, and the patient was started on intravenous (IV) methylprednisolone; he also received five sessions of plasmapheresis. By process of elimination, suspicion remained of a diagnosis of opioid-induced myelopathy. The patient showed mild improvement in his original sensory deficits and flaccid quadriplegia.

Extracellular vesicles derived from bone marrow mesenchymal stem cells enhance myelin maintenance after cortical injury in aged rhesus monkeys

Cortical injury, such as stroke, causes neurotoxic cascades that lead to rapid death and/or damage to neurons and glia. Axonal and myelin damage in particular, are critical factors that lead to neuronal dysfunction and impair recovery of function after injury. These factors can be exacerbated in the aged brain where white matter damage is prevalent. Therapies that can ameliorate myelin damage and promote repair by targeting oligodendroglia, the cells that produce and maintain myelin, may facilitate recovery after injury, especially in the aged brain where these processes are already compromised. We previously reported that a novel therapeutic, Mesenchymal Stem Cell derived extracellular vesicles (MSC-EVs), administered intravenously at both 24 h and 14 days after cortical injury, reduced microgliosis (Go et al. 2019), reduced neuronal pathology (Medalla et al. 2020), and improved motor recovery (Moore et al. 2019) in aged female rhesus monkeys. Here, we evaluated the effect of MSC-EV treatment on changes in oligodendrocyte maturation and associated myelin markers in the sublesional white matter using immunohistochemistry, confocal microscopy, stereology, qRT-PCR, and ELISA. Compared to vehicle control monkeys, EV-treated monkeys showed a reduction in the density of damaged oligodendrocytes. Further, EV-treatment was associated with enhanced myelin maintenance, evidenced by upregulation of myelin-related genes and increases in actively myelinating oligodendrocytes in sublesional white matter. These changes in myelination correlate with the rate of motor recovery, suggesting that improved myelin maintenance facilitates this recovery. Overall, our results suggest that EVs act on oligodendrocytes to support myelination and improves functional recovery after injury in the aged brain. SIGNIFICANCE: We previously reported that EVs facilitate recovery of function after cortical injury in the aged monkey brain, while also reducing neuronal pathology (Medalla et al. 2020) and microgliosis (Go et al. 2019). However, the effect of injury and EVs on oligodendrocytes and myelination has not been characterized in the primate brain (Dewar et al. 1999; Sozmen et al. 2012; Zhang et al. 2013). In the present study, we assessed changes in myelination after cortical injury in aged monkeys. Our results show, for the first time, that MSC-EVs support recovery of function after cortical injury by enhancing myelin maintenance in the aged primate brain.

The physiology of foamy phagocytes in multiple sclerosis

Multiple sclerosis (MS) is a chronic disease of the central nervous system characterized by massive infiltration of immune cells, demyelination, and axonal loss. Active MS lesions mainly consist of macrophages and microglia containing abundant intracellular myelin remnants. Initial studies showed that these foamy phagocytes primarily promote MS disease progression by internalizing myelin debris, presenting brain-derived autoantigens, and adopting an inflammatory phenotype. However, more recent studies indicate that phagocytes can also adopt a beneficial phenotype upon myelin internalization. In this review, we summarize and discuss the current knowledge on the spatiotemporal physiology of foamy phagocytes in MS lesions, and elaborate on extrinsic and intrinsic factors regulating their behavior. In addition, we discuss and link the physiology of myelin-containing phagocytes to that of foamy macrophages in other disorders such atherosclerosis.

Magnetic susceptibility increases as diamagnetic molecules breakdown: Myelin digestion during multiple sclerosis lesion formation contributes to increase on QSM

BACKGROUND

The pathological processes in the first weeks of multiple sclerosis (MS) lesion formation include myelin digestion that breaks chemical bonds in myelin lipid layers. This can increase lesion magnetic susceptibility, which is a potentially useful biomarker in MS patient management, but not yet investigated.

PURPOSE

To understand and quantify the effects of myelin digestion on quantitative susceptibility mapping (QSM) of MS lesions.

STUDY TYPE

Histological and QSM analyses on in vitro models of myelin breakdown and MS lesion formation in vivo.

POPULATION/SPECIMENS

Acutely demyelinating white matter lesions from MS autopsy tissue were stained with the lipid dye oil red O. Myelin basic protein (MBP), a major membrane protein of myelin, was digested with trypsin. Purified human myelin was denatured with sodium dodecyl sulfate (SDS). QSM was performed on phantoms containing digestion products and untreated controls. In vivo QSM was performed on five MS patients with newly enhancing lesions, and then repeated within 2 weeks.

FIELD STRENGTH/SEQUENCE

3D <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:msubsup><mml:mi>T</mml:mi> <mml:mn>2</mml:mn> <mml:mo>*</mml:mo></mml:msubsup> </mml:mrow> </mml:math> -weighted spoiled multiecho gradient echo scans performed at 3T.

ASSESSMENT

Region of interest analyses were performed by a biochemist and a neuroradiologist to determine susceptibility changes on in vitro and in vivo QSM images.

STATISTICAL TESTS

Not applicable.

RESULTS

MBP degradation by trypsin increased the QSM measurement by an average of 112 ± 37 ppb, in excellent agreement with a theoretical estimate of 111 ppb. Degradation of human myelin by SDS increased the QSM measurement by 23 ppb. As MS lesions changed from gadolinium enhancing to nonenhancing over an average of 15.8 ± 3.7 days, their susceptibility increased by an average of 7.5 ± 6.3 ppb.

DATA CONCLUSION

Myelin digestion in the early stages of MS lesion formation contributes to an increase in tissue susceptibility, detectable by QSM, as a lesion evolves from gadolinium enhancing to nonenhancing.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:1281-1287.

Myelin basic protein induces inflammatory mediators from primary human endothelial cells and blood-brain barrier disruption: implications for the pathogenesis of multiple sclerosis

AIM

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system, characterized by demyelination of white matter, loss of myelin forming oligodendrocytes, changes in the blood-brain barrier (BBB) and leucocyte infiltration. Myelin basic protein (MBP) is a component of the myelin sheath. Degradation of myelin is believed to be an important step that leads to MS pathology. Transmigration of leucocytes across the vasculature, and a compromised BBB participate in the neuroinflammation of MS. We examined the expression and regulation of the chemokine (C-C motif) ligand 2 (CCL2) and the cytokine interleukin-6 (IL-6) in human endothelial cells (EC), a component of the BBB, after treatment with MBP.

METHODS

EC were treated with full-length MBP. CCL2 and IL-6 protein were determined by ELISA. Western blot analysis was used to determine signalling pathways. A BBB model was treated with MBP and permeability was assayed using albumin conjugated to Evan's blue dye. The levels of the tight junction proteins occludin and claudin-1, and matrix metalloprotease (MMP)-2 were assayed by Western blot.

RESULTS

MBP significantly induced CCL2 and IL-6 protein from EC. This induction was partially mediated by the p38 MAPK pathway as there was phosphorylation after MBP treatment. MBP treatment of a BBB model caused an increase in permeability that correlated with a decrease in occludin and claudin-1, and an induction of MMP2.

CONCLUSION

These data demonstrate that MBP induces chemotactic and inflammatory mediators. MBP also alters BBB permeability and tight junction expression, indicating additional factors that may contribute to the BBB breakdown characteristic of MS.

Cerebrospinal fluid in multiple sclerosis

Background:

Technological advances have made it possible to examine the human cerebrospinal fluid (CSF) in a manner that was previously impossible. CSF provides a window into the changes that occur in the central nervous system (CNS) in health and disease. Through analysis of the CSF, we discern indirectly the state of health of the CNS, and correctly or incorrectly, draw conclusions regarding mechanisms of CNS injury and repair.

Objective, Materials and Methods:

To review the current state of knowledge of changes in the CSF in multiple sclerosis.

Discussion:

Establishing CSF markers that permit evaluation of the various biological processes in multiple sclerosis remains a challenge. Of all the biological processes, inflammatory markers are probably the best identified. Detection of oligoclonal immunoglobulin bands in the CSF is now established as the single most useful laboratory marker in the CSF to aid in the diagnosis of multiple sclerosis. Markers of demyelination, remyelination, neuro-axonal loss, neural repair and regeneration, and astrogliosis are only now being recognized. A good surrogate for any of these pathophysiological processes has not been defined to date.

Conclusion:

The goal of future research is not only to define surrogate markers in the CSF for each of the above functions, but also to extend it to other more readily accessible body fluids like blood and urine. A synopsis of the current literature in most of these areas of CSF evaluation pertaining to multiple sclerosis is presented in this article.

Luteolin inhibits myelin basic protein-induced human mast cell activation and mast cell-dependent stimulation of Jurkat T cells

BACKGROUND AND PURPOSE

Allergic inflammation and autoimmune diseases, such as atopic dermatitis, psoriasis and multiple sclerosis (MS), involve both mast cell and T-cell activation. However, possible interactions between the two and the mechanism of such activations are largely unknown.

EXPERIMENTAL APPROACH

Human umbilical cord blood-derived cultured mast cells (hCBMCs) and Jurkat T cells were incubated separately or together, following activation with myelin basic protein (MBP), as well as with or without pretreatment with the flavonoid luteolin for 15 min. The supernatant fluid was assayed for inflammatory mediators released from mast cells and interleukin (IL)-2 release from Jurkat cells.

KEY RESULTS

MBP (10 microM) stimulates hCBMCs to release IL-6, IL-8, transforming growth factor (TGF)-beta1, tumour necrosis factor-alpha (TNF-alpha), vascular endothelial growth factor (VEGF), histamine and tryptase (n=6, P<0.05). Addition of mast cells to Jurkat cells activated by anti-CD3/anti-CD28 increases IL-2 release by 30-fold (n=3, P<0.05). MBP-stimulated mast cells and their supernatant fluid further increase Jurkat cell IL-2 release (n=3, P<0.05). Separation of mast cells and activated Jurkat cells by a Transwell permeable membrane inhibits Jurkat cell stimulation by 60%. Pretreatment of Jurkat cells with a TNF-neutralizing antibody reduces IL-2 release by another 40%. Luteolin pretreatment inhibits mast cell activation (n=3-6, P<0.05), Jurkat cell activation and mast cell-dependent Jurkat cell stimulation (n=3, P<0.05).

CONCLUSIONS AND IMPLICATIONS

Mast cells can stimulate activated Jurkat cells. This interaction is inhibited by luteolin, suggesting that this flavonoid may be useful in the treatment of autoimmune diseases.

Detection of ectopic B-cell follicles with germinal centers in the meninges of patients with secondary progressive multiple sclerosis

Multiple sclerosis (MS) is characterized by synthesis of oligoclonal immunoglobulins and the presence of B-cell clonal expansions in the central nervous system (CNS). Because ectopic lymphoid tissue generated at sites of chronic inflammation is thought to be important in sustaining immunopathological processes, we have investigated whether structures resembling lymphoid follicles could be identified in the CNS of MS patients. Sections from post-mortem MS brains and spinal cords were screened using immunohistochemistry for the presence of CD20+ B-cells, CD3+ T-cells, CD138+ plasma cells and CD21+, CD35+ follicular dendritic cells, and for the expression of lymphoid chemokines (CXCL 13, CCL21) and peripheral node addressin (PNAd). Lymphoid follicle-like structures containing B-cells, T-cells and plasma cells, and a network of follicular dendritic cells producing CXCL13 were observed in the cerebral meninges of 2 out of 3 patients with secondary progressive MS, but not in relapsing remitting and primary progressive MS. We also show that proliferating B-cells are present in intrameningeal follicles, a finding which is suggestive of germinal center formation. No follicle-like structures were detected in parenchymal lesions. The formation of ectopic lymphoid follicies in the meninges of patients with MS could represent a critical step in maintaining humoral autoimmunity and in disease exacerbation.