Cuprizone-Induced Demyelination in Mouse Hippocampus Is Alleviated by Ketogenic Diet

Black Seed Oil-Based Curcumin Nanoformulations Ameliorated Cuprizone-Induced Demyelination in the Mouse Hippocampus

Multiple sclerosis (MS) is a neurodegenerative disease characterized by the demyelination of nerves, axonal damage, and neuroinflammation. Cognition impairment, pain, and loss of mobility are some of the usual complications of MS. It has been postulated that the overproduction of proinflammatory cytokines and reactive oxygen species (ROS) are the main factors that contribute to MS pathology. Among various animal models, the cuprizone model is the most widely used model for investigating MS-related pathology. We assessed the effects of cuprizone along with the protective effects of some black seed oil-based nanoformulations of curcumin with and without piperine, in mice hippocampus in terms of the changes in antioxidant enzymes, transcription factors, and cytokines during demyelination and remyelination processes. The results of behavioral studies point toward impairment in working memory following the feeding of cuprizone for 5 weeks. However, in treatment groups, mice seemed to prevent the toxic effects of cuprizone. Nanoformulations used in this study were found to be highly effective in lowering the amount of ROS as indicated by the levels of antioxidant enzymes like catalase, superoxide dismutase, glutathione, and glutathione peroxidase. Moreover, nanoformulations CCF and CCPF were observed resisting the toxic effects of cuprizone. We observed greater expression of NFκB-p65 in the CPZ group than in the control group. CCF nanoformulation had a better inhibitory effect on NFκB-p65 than other formulations. Histological examination of the hippocampus was also conducted. Nanoformulations used here were found effective in reversing MS-related pathophysiology and hence have the potential to be applied as adjuvant therapy for MS treatment.

Sex-specific effects of ketogenic diet on anxiety-like behavior and neuroimmune response in C57Bl/6J mice

The ketogenic diet (KD) has been shown to reduce anxiety and enhance cognitive functions in neurological diseases. However, the sex-specific effects of KD on anxiety-like behavior in healthy individuals and the underlying molecular mechanisms contributing to these effects, including neuroinflammation, are unelucidated. This study investigated the sex-specific effects of KD on anxiety-like behavior and the neuroimmune response in the prefrontal cortex (PFC) and hippocampus of healthy C57BL/6J male and female mice. Animals were fed either a control diet (CD- 17% fat, 65% carb, 18% protein) or a KD (80% fat, 5% carb, 15% protein) for 4 weeks. KD increased the levels of circulating β-hydroxybutyrate (BHB) both in males and females. However, PFC BHB levels were found to be elevated only in KD males. Moreover, KD did not affect the behavior of females but improved motor abilities and reduced anxiety levels in males. KD suppressed the mRNA expression of the pan microglial markers (Cd68, P2ry12) and induced morphological changes in the male PFC microglia. A sex-specific decrease in IL1β and an increase in IL-10 levels was found in the PFC of KD males. A similar trend was observed in the hippocampus of males where KD reduced the mRNA expression of P2ry12, Il1β, and cFos. Additionally, BHB increased the production of IL-10 whereas it decreased the production of IL1β from human microglia in in-vitro conditions. In summary, these results demonstrate that the anxiolytic and motor function enhancement abilities of KD are male-specific. Reduced pro-inflammatory and improved anti-inflammatory factors in the male PFC and hippocampus may underlie these effects.

Digestive and Absorptive Properties of the Antarctic Krill Tripeptide Phe-Pro-Phe (FPF) and Its Auxiliary Memory-Enhancing Effect

Aging and stress have contributed to the development of memory disorders. Phe-Pro-Phe (FPF) was identified with high stability by mass spectrometry from simulated gastrointestinal digestion and everted gut sac products of the Antarctic krill peptide Ser-Ser-Asp-Ala-Phe-Phe-Pro-Phe-Arg (SSDAFFPFR) which was found to have a positive impact on memory enhancement. This study investigated the digestive stability, absorption, and memory-enhancing effects of FPF using nuclear magnetic resonance spectroscopy, simulated gastrointestinal digestion, in vivo fluorescence distribution analysis, mouse behavioral experiments, acetylcholine function, Nissl staining, immunofluorescence, and immunohistochemistry. FPF crossed the blood-brain barrier into the brain after digestion, significantly reduced shock time, working memory errors, and reference memory errors, and increased the recognition index. Additionally, FPF elevated ACh content; Nissl body counts; and CREB, SYN, and PSD-95 expression levels, while reducing AChE activity (P < 0.05). This implies that FPF prevents scopolamine-induced memory impairment and provides a basis for future research on memory disorders.

Acer truncatum Bunge seed oil ameliorated oxaliplatin-induced demyelination by improving mitochondrial dysfunction via the Pink1/Parkin mitophagy pathway

Dietary nutritional support for special populations is an effective and feasible method to improve the quality of life of patients and reduce medical pressure. Acer truncatum Bunge seed oil (ATSO) is widely recognized for its ability to promote nerve myelin regeneration. To evaluate the ameliorative effects of ATSO on chemotherapy-induced demyelination, a zebrafish model of chemotherapy-induced demyelination was established. The results showed that 100 μg mL-1 of ATSO reversed tail morphology damage, axon degeneration, touch response delay, ROS level upregulation and the expression of myelin basic protein decrease in chemotherapy-induced zebrafish. In addition, the expression of myelin markers (including sox10, krox20, and pmp22) in oxaliplatin-induced cells was markedly reversed by ATSO and its active components (gondoic acid, erucic acid, and nervonic acid). ATSO and its active components could reverse demyelination by ameliorating mitochondrial dysfunction. Conversely, linoleic acid and linolenic acid promoted demyelination by exacerbating mitochondrial dysfunction. Moreover, the Pink1/Parkin pathway was recognized as the main reason for ATSO and its active components improving mitochondrial function by activating mitophagy and restoring autophagic flow. Taken together, this study demonstrated that ATSO and its active components could be further developed as novel functional food ingredients to antagonize demyelination.

A High MCT-Based Ketogenic Diet Suppresses Th1 and Th17 Responses to Ameliorate Experimental Autoimmune Encephalomyelitis in Mice by Inhibiting GSDMD and JAK2-STAT3/4 Pathways

SCOPE

Inflammation and pyroptosis play important roles in the pathogenesis of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). In this study, we evaluated the therapeutic potential of ketogenic diet (KD) in EAE.

METHODS AND RESULTS

The administration of KD reduces demyelination and microglial activation in the spinal cord of EAE mice. Meanwhile, KD decreases the levels of Th1 and Th17 associated cytokines/transcription factors production (T-bet, IFN-γ, RORγt, and IL-17) and increases those of Th2 and Treg cytokines/transcription factors (GATA3, IL-4, Foxp3, and IL-10) in the spinal cord and spleen. Corresponding, KD reduces the expression of chemokines in EAE, which those chemokines associate with T-cell infiltration into central nervous system (CNS). In addition, KD inhibits the GSDMD activation in microglia, oligodendrocyte, CD31+ cells, CCR2+ cells, and T cells in the spinal cord. Moreover, KD significantly decreases the ratios of p-JAK2/JAK2, p-STAT3/STAT3, and p-STAT4/STAT4, as well as GSDMD in EAE mice.

CONCLUSIONS

this study demonstrates that KD reduces the activation and differentiation of T cells in the spinal cord and spleen and prevents T cell infiltration into CNS of EAE via modulating the GSDMD and STAT3/4 pathways, suggesting that KD is a potentially effective strategy in the treatment of MS.

Astrocytes: Lessons Learned from the Cuprizone Model

A diverse array of neurological and psychiatric disorders, including multiple sclerosis, Alzheimer's disease, and schizophrenia, exhibit distinct myelin abnormalities at both the molecular and histological levels. These aberrations are closely linked to dysfunction of oligodendrocytes and alterations in myelin structure, which may be pivotal factors contributing to the disconnection of brain regions and the resulting characteristic clinical impairments observed in these conditions. Astrocytes, which significantly outnumber neurons in the central nervous system by a five-to-one ratio, play indispensable roles in the development, maintenance, and overall well-being of neurons and oligodendrocytes. Consequently, they emerge as potential key players in the onset and progression of a myriad of neurological and psychiatric disorders. Furthermore, targeting astrocytes represents a promising avenue for therapeutic intervention in such disorders. To gain deeper insights into the functions of astrocytes in the context of myelin-related disorders, it is imperative to employ appropriate in vivo models that faithfully recapitulate specific aspects of complex human diseases in a reliable and reproducible manner. One such model is the cuprizone model, wherein metabolic dysfunction in oligodendrocytes initiates an early response involving microglia and astrocyte activation, culminating in multifocal demyelination. Remarkably, following the cessation of cuprizone intoxication, a spontaneous process of endogenous remyelination occurs. In this review article, we provide a historical overview of studies investigating the responses and putative functions of astrocytes in the cuprizone model. Following that, we list previously published works that illuminate various aspects of the biology and function of astrocytes in this multiple sclerosis model. Some of the studies are discussed in more detail in the context of astrocyte biology and pathology. Our objective is twofold: to provide an invaluable overview of this burgeoning field, and, more importantly, to inspire fellow researchers to embark on experimental investigations to elucidate the multifaceted functions of this pivotal glial cell subpopulation.

Ketogenic diet attenuates neuroinflammation and induces conversion of M1 microglia to M2 in an EAE model of multiple sclerosis by regulating the NF-κB/NLRP3 pathway and inhibiting HDAC3 and P2X7R activation

Multiple sclerosis (MS) is an autoimmune disorder characterized by demyelination and neurodegeneration in the central nervous system (CNS); severe symptoms lead MS patients to use complementary treatments. Ketogenic diet (KD) shows wide neuroprotective effects, but the precise mechanisms underlying the therapeutic activity of KD in MS are unclear. The present study established a continuous 24 days experimental autoimmune encephalomyelitis (EAE) mouse model with or without KD. The changes in motor function, pathological hallmarks of EAE, the status of microglia, neuroinflammatory response and intracellular signaling pathways in mice were detected by the rotarod test, histological analysis, real-time PCR (RT-PCR) and western blotting. Our results showed that KD could prevent motor deficiency, reduce clinical scores, inhibit demyelination, improve pathological lesions and suppress microglial activation in the spinal cord of EAE mice. Meanwhile, KD shifted microglial polarization toward the protective M2 phenotype and modified the inflammatory milieu by downregulating the production of pro-inflammatory cytokines, including TNF-α, IL-1β and IL-6, as well as upregulating the release of anti-inflammatory cytokines such as TGF-β. Furthermore, KD decreased the expression levels of CCL2, CCR2, CCL3, CCR1, CCR5, CXCL10 and CXCR3 in the spinal cord and spleen with reduced monocyte/macrophage infiltration in the CNS. In addition, KD inhibits NLRP3 activation in the microglia, as revealed by the significantly decreased co-expression of NLRP3+ and Iba-1+ in the KD + EAE group. Further studies demonstrated that KD suppresses inflammatory response and M1 microglial polarization by inhibiting the TLR4/MyD88/NF-κB/NLRP3 pathway, the JAK1/STAT1 pathway, HDAC3 and P2X7R activation, as well as up-regulation of JAK3/STAT6.

Ketogenic diet: a potential adjunctive treatment for substance use disorders

Substance use disorders (SUD) can lead to serious health problems, and there is a great interest in developing new treatment methods to alleviate the impact of substance abuse. In recent years, the ketogenic diet (KD) has shown therapeutic benefits as a dietary therapy in a variety of neurological disorders. Recent studies suggest that KD can compensate for the glucose metabolism disorders caused by alcohol use disorder by increasing ketone metabolism, thereby reducing withdrawal symptoms and indicating the therapeutic potential of KD in SUD. Additionally, SUD often accompanies increased sugar intake, involving neural circuits and altered neuroplasticity similar to substance addiction, which may induce cross-sensitization and increased use of other abused substances. Reducing carbohydrate intake through KD may have a positive effect on this. Finally, SUD is often associated with mitochondrial damage, oxidative stress, inflammation, glia dysfunction, and gut microbial disorders, while KD may potentially reverse these abnormalities and serve a therapeutic role. Although there is much indirect evidence that KD has a positive effect on SUD, the small number of relevant studies and the fact that KD leads to side effects such as metabolic abnormalities, increased risk of malnutrition and gastrointestinal symptoms have led to the limitation of KD in the treatment of SUD. Here, we described the organismal disorders caused by SUD and the possible positive effects of KD, aiming to provide potential therapeutic directions for SUD.

Feeding the gut microbiome: impact on multiple sclerosis

Multiple sclerosis (MS) is a multifactorial neurological disease characterized by chronic inflammation and immune-driven demyelination of the central nervous system (CNS). The rising number of MS cases in the last decade could be partially attributed to environmental changes, among which the alteration of the gut microbiome driven by novel dietary habits is now of particular interest. The intent of this review is to describe how diet can impact the development and course of MS by feeding the gut microbiome. We discuss the role of nutrition and the gut microbiota in MS disease, describing preclinical studies on experimental autoimmune encephalomyelitis (EAE) and clinical studies on dietary interventions in MS, with particular attention to gut metabolites-immune system interactions. Possible tools that target the gut microbiome in MS, such as the use of probiotics, prebiotics and postbiotics, are analyzed as well. Finally, we discuss the open questions and the prospects of these microbiome-targeted therapies for people with MS and for future research.

Blood pH Analysis in Combination with Molecular Medical Tools in Relation to COVID-19 Symptoms

The global outbreak of SARS-CoV-2/COVID-19 provided the stage to accumulate an enormous biomedical data set and an opportunity as well as a challenge to test new concepts and strategies to combat the pandemic. New research and molecular medical protocols may be deployed in different scientific fields, e.g., glycobiology, nanopharmacology, or nanomedicine. We correlated clinical biomedical data derived from patients in intensive care units with structural biology and biophysical data from NMR and/or CAMM (computer-aided molecular modeling). Consequently, new diagnostic and therapeutic approaches against SARS-CoV-2 were evaluated. Specifically, we tested the suitability of incretin mimetics with one or two pH-sensitive amino acid residues as potential drugs to prevent or cure long-COVID symptoms. Blood pH values in correlation with temperature alterations in patient bodies were of clinical importance. The effects of biophysical parameters such as temperature and pH value variation in relation to physical-chemical membrane properties (e.g., glycosylation state, affinity of certain amino acid sequences to sialic acids as well as other carbohydrate residues and lipid structures) provided helpful hints in identifying a potential Achilles heel against long COVID. In silico CAMM methods and in vitro NMR experiments (including ³¹P NMR measurements) were applied to analyze the structural behavior of incretin mimetics and SARS-CoV fusion peptides interacting with dodecylphosphocholine (DPC) micelles. These supramolecular complexes were analyzed under physiological conditions by ¹H and ³¹P NMR techniques. We were able to observe characteristic interaction states of incretin mimetics, SARS-CoV fusion peptides and DPC membranes. Novel interaction profiles (indicated, e.g., by ³¹P NMR signal splitting) were detected. Furthermore, we evaluated GM1 gangliosides and sialic acid-coated silica nanoparticles in complex with DPC micelles in order to create a simple virus host cell membrane model. This is a first step in exploring the structure-function relationship between the SARS-CoV-2 spike protein and incretin mimetics with conserved pH-sensitive histidine residues in their carbohydrate recognition domains as found in galectins. The applied methods were effective in identifying peptide sequences as well as certain carbohydrate moieties with the potential to protect the blood-brain barrier (BBB). These clinically relevant observations on low blood pH values in fatal COVID-19 cases open routes for new therapeutic approaches, especially against long-COVID symptoms.

Cu,Zn-Superoxide Dismutase has Minimal Effects Against Cuprizone-Induced Demyelination, Microglial Activation, and Neurogenesis Defects in the C57BL/6 Mouse Hippocampus

Cuprizone causes consistent demyelination and oligodendrocyte damage in the mouse brain. Cu,Zn-superoxide dismutase 1 (SOD1) has neuroprotective potential against various neurological disorders, such as transient cerebral ischemia and traumatic brain injury. In this study, we investigated whether SOD1 has neuroprotective effects against cuprizone-induced demyelination and adult hippocampal neurogenesis in C57BL/6 mice, using the PEP-1-SOD1 fusion protein to facilitate the delivery of SOD1 protein into hippocampal neurons. Eight weeks feeding of cuprizone-supplemented (0.2%) diets caused a significant decrease in myelin basic protein (MBP) expression in the stratum lacunosum-moleculare of the CA1 region, the polymorphic layer of the dentate gyrus, and the corpus callosum, while ionized calcium-binding adapter molecule 1 (Iba-1)-immunoreactive microglia showed activated and phagocytic phenotypes. In addition, cuprizone treatment reduced proliferating cells and neuroblasts as shown using Ki67 and doublecortin immunostaining. Treatment with PEP-1-SOD1 to normal mice did not show any significant changes in MBP expression and Iba-1-immunoreactive microglia. However, Ki67-positive proliferating cells and doublecortin-immunoreactive neuroblasts were significantly decreased. Simultaneous treatment with PEP-1-SOD1 and cuprizone-supplemented diets did not ameliorate the MBP reduction in these regions, but mitigated the increase of Iba-1 immunoreactivity in the corpus callosum and alleviated the reduction of MBP in corpus callosum and proliferating cells, not neuroblasts, in the dentate gyrus. In conclusion, PEP-1-SOD1 treatment only has partial effects to reduce cuprizone-induced demyelination and microglial activation in the hippocampus and corpus callosum and has minimal effects on proliferating cells in the dentate gyrus.

Modulation of salivary ICAM-1 and SIRT1 by disease modifying drugs in undepressed relapsing-remitting multiple sclerosis patients

BACKGROUND

The pathophysiology of Multiple Sclerosis (MS) is multifactorial where the correlation between inflammation and MS is evident. Adhesion molecules such as Intercellular adhesion molecule-1 (ICAM-1) are implicated in MS. SIRT1 is a member of surtins family that play a protective role in neurodegenerative and inflammatory diseases. Although previously studied in Relapsing-Remitting Multiple Sclerosis (RRMS) patients, however the salivary expression of ICAM-1 and SIRT1 have not been yet studied in patients receiving fingolimod or interferon-β. Therefore, the present research aimed to investigate the expression of salivary ICAM-1 and SIRT1 in RRMS patients treated with fingolimod or interferon-β compared to controls.

METHODS

RRMS patients attending the neurology department of AL-Bashir Hospital were recruited. Patients' demographics, clinical information, and psychiatric status were evaluated (depression, anxiety and stress). Afterward, matched controls were recruited, then unstimulated whole saliva was obtained from the participants. The salivary expression of ICAM-1 and SIRT1 was investigated using western blot and normalized with β-actin.

RESULTS

Data were analyzed from 53 participants: 26 on fingolimod, 14 on interferon-β, and 13 control. The interferon-β treated patients showed a significantly (p < 0.001) higher ICAM-1 expression and lower SIRT1 expression (p < 0.05) compared to the control. Levels of ICAM-1 and SIRT1 did not vary between fingolimod and control.

CONCLUSION

ICAM-1 and SIRT1 expression might be affected with fingolimod or INF- β treatment which should be investigated more in the future.

Effect of β-hydroxybutyrate on behavioral alterations, molecular and morphological changes in CNS of multiple sclerosis mouse model

Multiple sclerosis (MS) is a chronic inflammatory and degenerative disease of central nervous system (CNS). Aging is the most significant risk factor for the progression of MS. Dietary modulation (such as ketogenic diet) and caloric restriction, can increase ketone bodies, especially β-hydroxybutyrate (BHB). Increased BHB has been reported to prevent or improve age-related disease. The present studies were performed to understand the therapeutic effect and potential mechanisms of exogenous BHB in cuprizone (CPZ)-induced demyelinating model. In this study, a continuous 35 days CPZ mouse model with or without BHB was established. The changes of behavior function, pathological hallmarks of CPZ, and intracellular signal pathways in mice were detected by Open feld test, Morris water maze, RT-PCR, immuno-histochemistry, and western blot. The results showed that BHB treatment improved behavioral performance, prevented myelin loss, decreased the activation of astrocyte as well as microglia, and up-regulated the neurotrophin brain-derived neurotrophic factor in both the corpus callosum and hippocampus. Meanwhile, BHB treatment increased the number of MCT1+ cells and APC+ oligodendrocytes. Furthermore, the treatment decreased the expression of HDAC3, PARP1, AIF and TRPA1 which is related to oligodendrocyte (OL) apoptosis in the corpus callosum, accompanied by increased expression of TrkB. This leads to an increased density of doublecortin (DCX)+ neuronal precursor cells and mature NeuN+ neuronal cells in the hippocampus. As a result, BHB treatment effectively promotes the generation of PDGF-Ra+ (oligodendrocyte precursor cells, OPCs), Sox2+ cells and GFAP+ (astrocytes), and decreased the production of GFAP+ TRAP1+ cells, and Oligo2+ TRAP1+ cells in the corpus callosum of mouse brain. Thus, our results demonstrate that BHB treatment efficiently supports OPC differentiation and decreases the OLs apoptosis in CPZ-intoxicated mice, partly by down-regulating the expression of TRPA1 and PARP, which is associated with the inhibition of the p38-MAPK/JNK/JUN pathway and the activation of ERK1/2, PI3K/AKT/mTOR signaling, supporting BHB treatment adjunctive nutritional therapy for the treatment of chronic demyelinating diseases, such as multiple sclerosis (MS).

Motor Behavioral Deficits in the Cuprizone Model: Validity of the Rotarod Test Paradigm

Multiple Sclerosis (MS) is a neuroinflammatory disorder, which is histopathologically characterized by multifocal inflammatory demyelinating lesions affecting both the central nervous system’s white and grey matter. Especially during the progressive phases of the disease, immunomodulatory treatment strategies lose their effectiveness. To develop novel progressive MS treatment options, pre-clinical animal models are indispensable. Among the various different models, the cuprizone de- and remyelination model is frequently used. While most studies determine tissue damage and repair at the histological and ultrastructural level, functional readouts are less commonly applied. Among the various overt functional deficits, gait and coordination abnormalities are commonly observed in MS patients. Motor behavior is mediated by a complex neural network that originates in the cortex and terminates in the skeletal muscles. Several methods exist to determine gait abnormalities in small rodents, including the rotarod testing paradigm. In this review article, we provide an overview of the validity and characteristics of the rotarod test in cuprizone-intoxicated mice.

HDAC3 Inhibitor RGFP966 Ameliorated Neuroinflammation in the Cuprizone-Induced Demyelinating Mouse Model and LPS-Stimulated BV2 Cells by Downregulating the P2X7R/STAT3/NF-κB65/NLRP3 Activation

Suppression of excessive microglial overactivation can prevent the progression of multiple sclerosis (MS). Histone deacetylases 3 inhibitor (HDAC3i) has been demonstrated to exert anti-inflammatory effects by suppressing microglia (M1-liked) activation. Here, we demonstrate that the RGFP966 (a selective inhibitor of HDAC3) protects white matter after cuprizone-induced demyelination, as shown by reductions in neurological behavioral deficits and increases in myelin basic protein. Moreover, in this study, we found that RGFP966 caused a significant reduction in the levels of inflammatory cytokines, including IL-1β, TNF-α, as well as iNOS, and inhibited microglial (M1-liked) activation in the experimental cuprizone model and LPS-stimulated BV2 cells. Meanwhile, RGFP966 alleviated apoptosis of LPS-induced BV2 cells in vitro. Furthermore, RGFP966 suppressed the expression of P2X7R, NLRP3, ASC, IL-18, IL-1β, and caspase-1, inhibited the ratio of phosphorylated-STAT3/STAT3 and phosphorylated NF-κB p65/NF-κB p65, as well as increased acetylated NF-κB p65 in vitro and in vivo. Furthermore, we confirmed that brilliant blue G (antagonists of P2X7R) suppressed the expression of microglial NLRP3, IL-18, IL-1β, caspase-1, NF-κB p65 (including phosphorylated NF-κB p65), and STAT3 (including phosphorylated STAT3) in vitro. These findings demonstrated that RFFP966 alleviated the inflammatory response and exerted a neuroprotective effect possibly by modulating P2X7R/STAT3/NF-κB65/NLRP3 signaling pathways. Thus, HDAD3 might be considered a promising intervention target for neurodegenerative diseases, such as MS.

Bu Shen Yi Sui Capsule Promotes Myelin Repair by Modulating the Transformation of A1/A2 Reactive Astrocytes In Vivo and In Vitro

Background/Aims. Multiple sclerosis (MS) is an autoimmune disorder that affects the central nervous system (CNS) primarily hallmarked by neuroinflammation and demyelination. The activation of astrocytes exerts double-edged sword effects, which perform an integral function in demyelination and remyelination. In this research, we examined the therapeutic effects of the Bu Shen Yi Sui capsule (BSYS), a traditional Chinese medicine prescription, in a cuprizone- (CPZ-) triggered demyelination model of MS (CPZ mice). This research intended to evaluate if BSYS might promote remyelination by shifting A1 astrocytes to A2 astrocytes. Methods. The effects of BSYS on astrocyte polarization and the potential mechanisms were explored in vitro and in vivo utilizing real-time quantitative reverse transcription PCR, immunofluorescence, and Western blotting. Histopathology, expression of inflammatory cytokines (IL-10, IL-1β, and IL-6), growth factors (TGF-β, BDNF), and motor coordination were assessed to verify the effects of BSYS (3.02 g/kg/d) on CPZ mice. In vitro, A1 astrocytes were induced by TNF-α (30 ng/mL), IL-1α (3 ng/mL), and C1q (400 ng/mL), following which the effect of BSYS-containing serum (concentration of 15%) on the transformation of A1/A2 reactive astrocytes was also evaluated. Results and Conclusions. BSYS treatment improved motor function in CPZ mice as assessed by rotarod tests. Intragastric administration of BSYS considerably lowered the proportion of A1 astrocytes, but the number of A2 astrocytes, MOG+, PLP+, CNPase+, and MBP+ cells was upregulated. Meanwhile, dysregulation of glutathione peroxidase, malondialdehyde, and superoxide dismutase was reversed in CPZ mice after treatment with BSYS. In addition, the lesion area and expression of proinflammatory cytokines were decreased and neuronal protection factors and anti-inflammatory cytokines were increased. In vitro, BSYS-containing serum suppressed the A1 astrocytic markers' expression and elevated the expression levels of A2 markers in primary astrocytes triggered by C1q, TNF-α, and IL-1α. Importantly, the miR-155/SOCS1 signaling pathway was involved in the modulation of the A1/A2 phenotype shift. Overall, this study demonstrated that BSYS has neuroprotective effects in myelin repair by modulating astrocyte polarization via the miR-155/SOCS1 pathway.

Role of Ketogenic Diets in Multiple Sclerosis and Related Animal Models: An Updated Review

Prescribing a ketogenic diet (KD) is a century-old dietary intervention mainly used in the context of intractable epilepsy. The classic KD and its variants regained popularity in recent decades, and they are considered potentially beneficial in a variety of neurological conditions other than epilepsy. Many patients with multiple sclerosis (MS) have attempted diet modification for better control of their disease, although evidence thus far remains insufficient to recommend a specific diet for these patients. The results of 3 pilot clinical trials of KD therapy for MS, as well as several related studies, have been reported in recent years. The preliminary findings suggest that KD is safe, feasible, and potentially neuroprotective and disease-modifying for patients with MS. Research on corresponding rodent models has also lent support to the efficacy of KD in the prevention and treatment of experimental autoimmune encephalomyelitis and toxin-induced inflammatory demyelinating conditions in the brain. Furthermore, the animal studies have yielded mechanistic insights into the molecular mechanisms of KD action in relevant situations, paving the way for precision nutrition. Herein we review and synthesize recent advances and also identify unresolved issues, such as the roles of adipokines and gut microbiota, in this field. Hopefully this panoramic view of current understanding can inform future research directions and clinical practice with regard to KD in MS and related conditions.

Neuroprotective Potential of Dendritic Cells and Sirtuins in Multiple Sclerosis

Myeloid cells, including parenchymal microglia, perivascular and meningeal macrophages, and dendritic cells (DCs), are present in the central nervous system (CNS) and establish an intricate relationship with other cells, playing a crucial role both in health and in neurological diseases. In this context, DCs are critical to orchestrating the immune response linking the innate and adaptive immune systems. Under steady-state conditions, DCs patrol the CNS, sampling their local environment and acting as sentinels. During neuroinflammation, the resulting activation of DCs is a critical step that drives the inflammatory response or the resolution of inflammation with the participation of different cell types of the immune system (macrophages, mast cells, T and B lymphocytes), resident cells of the CNS and soluble factors. Although the importance of DCs is clearly recognized, their exact function in CNS disease is still debated. In this review, we will discuss modern concepts of DC biology in steady-state and during autoimmune neuroinflammation. Here, we will also address some key aspects involving DCs in CNS patrolling, highlighting the neuroprotective nature of DCs and emphasizing their therapeutic potential for the treatment of neurological conditions. Recently, inhibition of the NAD⁺-dependent deac(et)ylase sirtuin 6 was demonstrated to delay the onset of experimental autoimmune encephalomyelitis, by dampening DC trafficking towards inflamed LNs. Thus, a special focus will be dedicated to sirtuins’ role in DCs functions.

Neuroprotective effect of liraglutide in an experimental mouse model of multiple sclerosis: role of AMPK/SIRT1 signaling and NLRP3 inflammasome

The heterogeneous nature of multiple sclerosis (MS) and the unavailability of treatments addressing its intricate network and reversing the disease state is yet an area that needs to be elucidated. Liraglutide, a glucagon-like peptide-1 analogue, recently exhibited intriguing potential neuroprotective effects. The currents study investigated its potential effect against mouse model of MS and the possible underlying mechanisms. Demyelination was induced in C57Bl/6 mice by cuprizone (400 mg/kg/day p.o.) for 5 weeks. Animals received either liraglutide (25 nmol/kg/day i.p.) or dorsomorphin, an AMPK inhibitor, (2.5 mg/Kg i.p.) 30 min before the liraglutide dose, for 4 weeks (starting from the second week). Liraglutide improved the behavioral profile in cuprizone-treated mice. Furthermore, it induced the re-myelination process through stimulating oligodendrocyte progenitor cells differentiation via Olig2 transcription activation, reflected by increased myelin basic protein and myelinated nerve fiber percentage. Liraglutide elevated the protein content of p-AMPK and SIRT1, in addition to the autophagy proteins Beclin-1 and LC3B. Liraglutide halted cellular damage as manifested by reduced HMGB1 protein and consequently TLR-4 downregulation, coupled with a decrease in NF-κB. Liraglutide also suppressed NLRP3 transcription. Dorsomorphin pre-administration indicated a possible interplay between AMPK/SIRT1 and NLRP3 inflammasome activation as it partially reversed liraglutide’s effects. Immunohistochemical examination of Iba⁺ microglia emphasized these findings. In conclusion, liraglutide exerts neuroprotection against cuprizone-induced demyelination via anti-inflammatory, autophagic flux activation, NLRP3 inflammasome suppression, and anti-apoptotic mechanisms, possibly mediated, at least in part, via AMPK/SIRT1, autophagy, TLR-4/ NF-κB/NLRP3 signaling.

A comparative study of the effect of a gentle ketogenic diet containing medium-chain or long-chain triglycerides on chronic sleep deprivation-induced cognitive deficiency

The ketogenic diet (KD) is well known for its neuroprotective effect, but little is known about its prophylactic efficacy against chronic sleep deprivation (SD) induced cognitive deficiency. An emerging study indicated that ferroptosis plays an important role in neurologic diseases but has been rarely reported in chronic SD. Here, we investigated the prophylactic effects of a medium-chain triglyceride-enriched KD (MKD) and a long-chain triglyceride-enriched KD (LKD) on cognitive deficiency and revealed the underlying mechanism focused on ferroptosis in chronic SD model mice. The results showed that the MKD exhibited stronger effects than the LKD on improving cognitive deficiency via suppressing ferroptosis and improving synaptic plasticity. Further mechanism results indicated that MKD produced higher Sirt3 protein levels than LKD, which probably contributed to the synergistic effect of beta hydroxybutyric acid and decanoic acid. Our finds provide novel evidence for the KD as a safe and feasible dietary intervention to prevent chronic SD-induced cognitive deficiency, and suggest a better choice of medium-chain fatty acid-enriched KD.

Neuroprotection by the Ketogenic Diet: Evidence and Controversies

The ketogenic diet (KD) is a high-fat low-carbohydrate diet that has been used for decades as a non-pharmacologic approach to treat metabolic disorders and refractory pediatric epilepsy. In recent years, enthusiasm for the KD has increased in the scientific community due to evidence that the diet reduces pathology and improves various outcome measures in animal models of neurodegenerative disorders, including multiple sclerosis, stroke, glaucoma, spinal cord injury, retinal degenerations, Parkinson's disease and Alzheimer's disease. Clinical trials also suggest that the KD improved quality of life in patients with multiple sclerosis and Alzheimer's disease. Furthermore, the major ketone bodies BHB and ACA have potential neuroprotective properties and are now known to have direct effects on specific inflammatory proteins, transcription factors, reactive oxygen species, mitochondria, epigenetic modifications and the composition of the gut microbiome. Neuroprotective benefits of the KD are likely due to a combination of these cellular processes and other potential mechanisms that are yet to be confirmed experimentally. This review provides a comprehensive summary of current evidence for the effectiveness of the KD in humans and preclinical models of various neurological disorders, describes molecular mechanisms that may contribute to its beneficial effects, and highlights key controversies and current gaps in knowledge.

Trifluoperazine reduces cuprizone-induced demyelination via targeting Nrf2 and IKB in mice

Multiple sclerosis (MS) is one of the most common neurodegenerative diseases. In this disease, the immune system attacks oligodendrocyte cells and the myelin sheath of myelinated neurons in the central nervous system, causing their destruction. These conditions lead to impaired conduction of nerve impulses and are manifested by symptoms such as weakness, fatigue, visual and motor disorders. This study aimed to evaluate the ability of trifluoperazine (TF) to improve cuprizone-induced behavioral and histopathological changes in the prefrontal cortex of C57BL/6 male mice. Demyelination was induced by adding 0.2% cuprizone (CPZ) to the standard animal diet for 6 weeks. Three doses of TF (0.5, 1 and 2 mg/kg/day; i.p.) were given once daily for the last 2 weeks of treatment. Treatment with CPZ induced a weight loss during 6 weeks of treatment compared to the control group, which was reversed by the administration of TF. Behavioral tests (pole test and rotarod performance test) showed a decrease in motor coordination and balance in the group treated with CPZ (P < 0.01). Treatment with TF during the last two weeks was able to improve these motor deficiencies. Histopathological examination also evidenced an increase in demyelination in the CPZ group, which was improved by TF administration. In addition, CPZ intake significantly decreased the cerebral cortex levels of p-Nrf2 (P < 0.001) and increased the levels of p-IKB (P < 0.001) and, these changes were normalized in the TF groups. TF administration also reversed the increased levels of nitrite and the reduced activity of the antioxidant enzyme superoxide dismutase associated with CPZ exposure. TF can to reduce the harmful effects of CPZ by reducing the demyelination and modulating the Nrf2 and NF-kB signaling pathways.

Effects of Venlafaxine, Risperidone and Febuxostat on Cuprizone-Induced Demyelination, Behavioral Deficits and Oxidative Stress

Multiple sclerosis (MS) is a demyelinating, autoimmune disease that affects a large number of young adults. Novel therapies for MS are needed considering the efficiency and safety limitations of current treatments. In our study, we investigated the effects of venlafaxine (antidepressant, serotonin-norepinephrine reuptake inhibitor), risperidone (atypical antipsychotic) and febuxostat (gout medication, xanthine oxidase inhibitor) in the cuprizone mouse model of acute demyelination, hypothesizing an antagonistic effect on TRPA1 calcium channels. Cuprizone and drugs were administered to C57BL6/J mice for five weeks and locomotor activity, motor performance and cold sensitivity were assessed. Mice brains were harvested for histological staining and assessment of oxidative stress markers. Febuxostat and metabolites of venlafaxine (desvenlafaxine) and risperidone (paliperidone) were tested for TRPA1 antagonistic activity. Following treatment, venlafaxine and risperidone significantly improved motor performance and sensitivity to a cold stimulus. All administered drugs ameliorated the cuprizone-induced deficit of superoxide dismutase activity. Desvenlafaxine and paliperidone showed no activity on TRPA1, while febuxostat exhibited agonistic activity at high concentrations. Our findings indicated that all three drugs offered some protection against the effects of cuprizone-induced demyelination. The agonistic activity of febuxostat can be of potential use for discovering novel TRPA1 ligands.

In Vivo Measurement of Neurochemical Abnormalities in the Hippocampus in a Rat Model of Cuprizone-Induced Demyelination

This study quantitatively measured the changes in metabolites in the hippocampal lesions of a rat model of cuprizone-induced demyelination as detected using in vivo 7 T proton magnetic resonance spectroscopy. Nineteen Sprague Dawley rats were randomly divided into two groups and fed a normal chow diet or cuprizone (0.2%, w/w) for 7 weeks. Demyelinated hippocampal lesions were quantitatively measured using a 7 T magnetic resonance imaging scanner. All proton spectra were quantified for metabolite concentrations and relative ratios. Compared to those in the controls, the cuprizone-induced rats had significantly higher concentrations of glutamate (p = 0.001), gamma-aminobutyric acid (p = 0.019), and glutamate + glutamine (p = 0.001); however, creatine + phosphocreatine (p = 0.006) and myo-inositol (p = 0.001) concentrations were lower. In addition, we found that the glutamine and glutamate complex/total creatine (p < 0.001), glutamate/total creatine (p < 0.001), and GABA/total creatine (p = 0.002) ratios were significantly higher in cuprizone-treated rats than in control rats. Our results showed that cuprizone-induced neuronal demyelination may influence the severe abnormal metabolism in hippocampal lesions, and these responses could be caused by microglial activation, mitochondrial dysfunction, and astrocytic necrosis.