Inflammatory mediators as biomarkers in brain disorders

Autistic spectrum disorder (ASD) - Gene, molecular and pathway signatures linking systemic inflammation, mitochondrial dysfunction, transsynaptic signalling, and neurodevelopment

Background

Despite advances in autism spectrum disorder (ASD) research and the vast genomic, transcriptomic, and proteomic data available, there are still controversies regarding the pathways and molecular signatures underlying the neurodevelopmental disorders leading to ASD.

Purpose

To delineate these underpinning signatures, we examined the two largest gene expression meta-analysis datasets obtained from the brain and peripheral blood mononuclear cells (PBMCs) of 1355 ASD patients and 1110 controls.

Methods

We performed network, enrichment, and annotation analyses using the differentially expressed genes, transcripts, and proteins identified in ASD patients.

Results

Transcription factor network analyses in up- and down-regulated genes in brain tissue and PBMCs in ASD showed eight main transcription factors, namely: BCL3, CEBPB, IRF1, IRF8, KAT2A, NELFE, RELA, and TRIM28. The upregulated gene networks in PBMCs of ASD patients are strongly associated with activated immune-inflammatory pathways, including interferon-α signaling, and cellular responses to DNA repair. Enrichment analyses of the upregulated CNS gene networks indicate involvement of immune-inflammatory pathways, cytokine production, Toll-Like Receptor signalling, with a major involvement of the PI3K-Akt pathway. Analyses of the downregulated CNS genes suggest electron transport chain dysfunctions at multiple levels. Network topological analyses revealed that the consequent aberrations in axonogenesis, neurogenesis, synaptic transmission, and regulation of transsynaptic signalling affect neurodevelopment with subsequent impairments in social behaviours and neurocognition. The results suggest a defense response against viral infection.

Conclusions

Peripheral activation of immune-inflammatory pathways, most likely induced by viral infections, may result in CNS neuroinflammation and mitochondrial dysfunction, leading to abnormalities in transsynaptic transmission, and brain neurodevelopment.

miRNAs as potential diagnostic biomarkers and pharmacogenomic indicators in psychiatric disorders

The heterogeneity of psychiatric disorders and the lack of reliable biomarkers for prediction and treatments follow-up pose difficulties towards recognition and understanding of the molecular basis of psychiatric diseases. However, several studies based on NGS approaches have shown that miRNAs could regulate gene expression during onset and disease progression and could serve as potential diagnostic and pharmacogenomics biomarkers during treatment. We provide herein a detailed overview of circulating miRNAs and their expression profiles as biomarkers in schizophrenia, bipolar disorder and major depressive disorder and their role in response to specific treatments. Bioinformatics analysis of miR-34a, miR-106, miR-134 and miR-132, which are common among SZ, BD and MDD patients, showed brain enrichment and involvement in the modulation of critical signaling pathways, which are often deregulated in psychiatric disorders. We propose that specific miRNAs support accurate diagnosis and effective precision treatment of psychiatric disorders.

Obesity as a Risk Factor for Dementia and Alzheimer's Disease: The Role of Leptin

Obesity is a growing worldwide health problem, affecting many people due to excessive saturated fat consumption, lack of exercise, or a sedentary lifestyle. Leptin is an adipokine secreted by adipose tissue that increases in obesity and has central actions not only at the hypothalamic level but also in other regions and nuclei of the central nervous system (CNS) such as the cerebral cortex and hippocampus. These regions express the long form of leptin receptor LepRb, which is the unique leptin receptor capable of transmitting complete leptin signaling, and are the first regions to be affected by chronic neurocognitive deficits, such as mild cognitive impairment (MCI) and Alzheimer's Disease (AD). In this review, we discuss different leptin resistance mechanisms that could be implicated in increasing the risk of developing AD, as leptin resistance is frequently associated with obesity, which is a chronic low-grade inflammatory state, and obesity is considered a risk factor for AD. Key players of leptin resistance are SOCS3, PTP1B, and TCPTP whose signalling is related to inflammation and could be worsened in AD. However, some data are controversial, and it is necessary to further investigate the underlying mechanisms of the AD-causing pathological processes and how altered leptin signalling affects such processes.

Post-Acute COVID-19 Neurological Syndrome: A New Medical Challenge

In December 2019, in Wuhan (China), a highly pathogenic coronavirus, named SARS-CoV-2, dramatically emerged. This new virus, which causes severe pneumonia, is rapidly spreading around the world, hence it provoked the COVID-19 pandemic. This emergency launched by SARS-CoV-2 also had, and still has, devastating socio-economic aspects. Assessing the impact of COVID-19 on vulnerable groups of people is crucial for the adaptation of governments' responses. Growing scientific evidence suggests that it is essential to keep the attention on people after acute SARS-CoV-2 infection; indeed, some clinical manifestations are frequently present even after recovery. There is consensus on the need to define which symptoms persist after the infection and which disabilities may arise after COVID-19. Recent reviews, case reports, and original contributions suggest that various organs may be affected, and neurological symptoms are present in about one third of patients with COVID-19. Neurological complications after severe COVID-19 infection might include delirium, brain inflammation, stroke, and nerve damage. In the recent pandemic, neurologists and neurobiologists have a chance to study key features of infection neurology. Furthermore, the psychological impact of the pandemic should not be underestimated, although there is currently no definition for this condition.

Potential neurological effects of severe COVID-19 infection

Coronaviruses (CoVs) are large positive stranded enveloped RNA viruses that generally cause enteric and respiratory diseases in humans and in animals. Most human CoVs have recently attracted global attention to their lethal potential and great infectious capacity. A highly pathogenic CoV, called COVID-19 or SARS-CoV-2, dramatically emerged in December 2019 in Wuhan, China. This new CoV has caused severe pneumonia in China and rapidly spreads around the world, the COVID-19 pandemic. Growing evidence pieces show that viruses, such as CoVs, can enter the central nervous system from different pathways and inducing neurotoxicity. Therefore, it is urgent to make clear whether SARS-CoV-2 has access to the central nervous system and can cause direct neuronal effects. Moreover, a brain-lung-brain axis is been proposed from the scientific community where severe neurological dysfunction and injury are associated with lung injury, and vice versa. In this axis, virus-induced inflammation and oxidative stress could be the common mechanisms responsible for CoV neurological symptoms. Therefore, is important to make clear whether SARS-CoV-2 lung damage can cause direct or indirect neuronal effects.

The Anti-Inflammatory Role of Omega-3 Polyunsaturated Fatty Acids Metabolites in Pre-Clinical Models of Psychiatric, Neurodegenerative, and Neurological Disorders

Inflammation has been identified as one of the main pathophysiological mechanisms underlying neuropsychiatric and neurodegenerative disorders. Despite the role of inflammation in those conditions, there is still a lack of effective anti-inflammatory therapeutic strategies. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) can reduce depressive symptoms and exert anti-inflammatory action putatively by the production of distinct n-3 PUFA-derived metabolites, such as resolvins D (RvD) and E (RvE) series, maresins (MaR) and protectins (PD), which are collectively named specialized pro-resolving mediators (SPMs) and act as strong anti-inflammatory agents. In this review we summarize evidence showing the effects of treatment with those metabolites in pre-clinical models of psychiatric, neurodegenerative and neurological disorders. A total of 25 pre-clinical studies were identified using the PubMed database. Overall, RvD and RvE treatment improved depressive-like behaviors, whereas protectins and maresins ameliorated neurological function. On a cellular level, RvDs increased serotonin levels in a model of depression, and decreased gliosis in neurodegenerative disorders. Protectins prevented neurite and dendrite retraction and apoptosis in models of neurodegeneration, while maresins reduced cell death across all studies. In terms of mechanisms, all SPMs down-regulated pro-inflammatory cytokines. Resolvins activated mTOR and MAP/ERK signaling in models of depression, while resolvins and maresins activated the NF-κB pathway in models of neurodegeneration and neurological disorders. Our review indicates a potential promising approach for tailored therapy with n-3 PUFAs-derived metabolites in the treatment of psychiatric, neurodegenerative, and neurological conditions.

Neural Glyoxalase Pathway Enhancement by Morin Derivatives in an Alzheimer's Disease Model

The glyoxalase pathway (GP) is an antioxidant defense system that detoxifies metabolic byproduct methylglyoxal (MG). Through sequential reactions, reduced glutathione (GSH), glyoxalase I (glo-1), and glyoxalase II (glo-2) convert MG into d-lactate. Spontaneous reactions involving MG alter the structure and function of cellular macromolecules through the formation of inflammatory advanced glycation endproducts (AGEs). Accumulation of MG and AGEs in neural cells contributes to oxidative stress (OS), a state of elevated inflammation commonly found in neurodegenerative diseases including Alzheimer's disease (AD). Morin is a common plant-produced flavonoid polyphenol that exhibits the ability to enhance the GP-mediated detoxification of MG. We hypothesize that structural modifications to morin will improve its inherent GP enhancing ability. Here we synthesized a morin derivative, dibromo-morin (DBM), formulated a morin encapsulated nanoparticle (MNP), and examined their efficacy in enhancing neural GP activity. Cultured mouse primary cerebellar neurons and Caenorhabditis elegans were induced to a state of OS with MG and treated with morin, DBM, and MNP. Results indicated the morin derivatives were more effective compared to the parent compound in neural GP enhancement and preventing MG-mediated OS in an AD model.

β-Amyloid Peptide: the Cell Compartment Multi-faceted Interaction in Alzheimer's Disease

Alzheimer's disease (AD) is the most widespread form of dementia, characterized by memory loss and reduction of cognitive functions that strongly interfere with normal daily life. Numerous evidences show that aggregates of the amyloid beta peptide, formed by 39 to 42 amino acid residues (Aβ39-43), from soluble small oligomers to large fibrils are characteristic markers of this pathology. However, AD is a complex disease and its neurodegenerative molecular mechanism is not yet fully understood. Growing evidence suggests a link between Aβ polymorphic nature, oligomers and fibrils, and specific mechanisms of neurodegeneration. The Aβ variable nature and its multiplicity of interactions with different proteins and organelles reflect the complexity of this pathology. In this review, we analyze the effects of the interaction between Aβ peptide and different cellular compartments in relation to the different kinds and sizes of amyloid aggregates. In particular, Aβ interaction with different cell structures such as the plasma membrane, mitochondria, lysosomes, nucleus, and endoplasmic reticulum is discussed. Further, we analyze the Aβ peptide ability to modify the structure and function of the target organelle, inducing alteration of its physiological role thus contributing to the pathological event. Dysfunction of cellular components terminating with the activation of the cellular death mechanism and subsequent neurodegeneration is also taken into consideration.

Heat-Resistant Aphanizomenon flos-aquae (AFA) Extract (Klamin®) as a Functional Ingredient in Food Strategy for Prevention of Oxidative Stress

Microalgae are generally considered an excellent source of vitamins, minerals, and bioactive molecules that make them suitable to be introduced in cosmetics, pharmaceuticals, and food industries. Aphanizomenon flos-aquae (AFA), an edible microalga, contains numerous biomolecules potentially able to prevent some pathologies including age-related disorders. With the aim to include an AFA extract (Klamin®) as a functional ingredient in baked products, we investigated if its bioactive molecules are destroyed or inactivated after standard cooking temperature. The AFA extract was exposed to heat stress (AFA-HS), and no significant decrease in pigment, polyphenol, and carotenoid content was detected by spectroscopic analysis. Thermal stability of AFA-HS extract was demonstrated by thermogravimetric analysis (TGA), and no change in the morphology of the granules of the powder was noticed by SEM microscopic observation. By Folin-Ciocalteu, ORAC, and ABTS assays, no change in the antioxidant activity and polyphenol contents was found after high-temperature exposition. When added in cell culture, solubilized AFA-HS lost neither its scavenging ability against ROS generation nor its protective role against Abeta, the main peptide involved in Alzheimer's disease. Prebiotic and antioxidant activities of AFA extract that are not lost after thermal stress were verified on E. coli bacteria. Finally, AFA-HS cookies, containing the extract as one of their ingredients, showed increased polyphenols. Here, we evaluate the possibility to use the AFA extract to produce functional food and prevent metabolic and age-related diseases.

Dietary Inflammatory Index and Sleep Quality in Southern Italian Adults

BACKGROUND

Current evidence supports the central role of a subclinical, low-grade inflammation in a number of chronic illnesses and mental disorders; however, studies on sleep quality are scarce. The aim of this study was to test the association between the inflammatory potential of the diet and sleep quality in a cohort of Italian adults.

METHODS

A cross-sectional analysis of baseline data of the Mediterranean healthy Eating, Aging, and Lifestyle (MEAL) study was conducted on 1936 individuals recruited in the urban area of Catania during 2014-2015 through random sampling. A food frequency questionnaire and other validated instruments were used to calculate the dietary inflammatory index (DII®) and assess sleep quality (Pittsburg sleep quality index). Multivariable logistic regression analyses were performed to determine the association between exposure and outcome.

RESULTS

Individuals in the highest quartile of the DII were less likely to have adequate sleep quality (odds ratio (OR) = 0.49, 95% CI: 0.31, 0.78). Among individual domains of sleep quality, an association with the highest exposure category was found only for sleep latency (OR = 0.60, 95% CI: 0.39, 0.93).

CONCLUSIONS

The inflammatory potential of the diet appears to be associated with sleep quality in adults. Interventions to improve diet quality might consider including a dietary component that aims to lower chronic systemic inflammation to prevent cognitive decline and improve sleep quality.

Developmental roles of microglia: A window into mechanisms of disease

Microglia are engineers of the central nervous system (CNS) both in health and disease. In addition to the canonical immunological roles of clearing damaging entities and limiting the spread of toxicity and death, microglia remodel the CNS throughout life. While they have been extensively studied in disease and injury, due to their highly variable functions, their precise role in these contexts still remains uncertain. Over the past decade, we have greatly expanded our understanding of microglial function, including their essential homeostatic roles during development. Here, we review these developmental roles, identify parallels in disease, and speculate whether developmental mechanisms re-emerge in disease and injury. Developmental Dynamics 248:98-117, 2019. © 2018 Wiley Periodicals, Inc.

In vivo molecular imaging of neuroinflammation in Alzheimer's disease

It has become increasingly evident that neuroinflammation plays a critical role in the pathophysiology of Alzheimer's disease (AD) and other neurodegenerative disorders. Increased glial cell activation is consistently reported in both rodent models of AD and in AD patients. Moreover, recent genome wide association studies have revealed multiple genes associated with inflammation and immunity are significantly associated with an increased risk of AD development (e.g. TREM2). Non‐invasive in vivo detection and tracking of neuroinflammation is necessary to enhance our understanding of the contribution of neuroinflammation to the initiation and progression of AD. Importantly, accurate methods of quantifying neuroinflammation may aid early diagnosis and serve as an output for therapeutic monitoring and disease management. This review details current in vivo imaging biomarkers of neuroinflammation being explored and summarizes both pre‐clinical and clinical results from molecular imaging studies investigating the role of neuroinflammation in AD, with a focus on positron emission tomography and magnetic resonance spectroscopy (MRS).

Inflammation is correlated with severity and outcome of cerebral venous thrombosis

BACKGROUND

Few studies have suggested a relationship between inflammation and cerebral venous thrombosis (CVT). This retrospective study aimed to explore the changes in inflammation in different CVT stages and the correlation between inflammation and severity and outcome of CVT.

METHODS

In total, 95 suitable patients with CVT and 41 controls were compared. Patients with CVT were divided into three groups. The inflammatory factors studied included hypersensitive C-reactive protein (Hs-CRP), interleukin-6 (IL-6), and neutrophil-to-lymphocyte ratio (NLR) in the peripheral blood and immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG) in the cerebrospinal fluid (CSF). The severity of CVT was evaluated with the modified Rankin Scale (mRS), the National Institutes of Health Stroke Scale (NIHSS), fundus condition, intracranial pressure (ICP), and complications on admission. The short-term outcome was evaluated with the mRS at discharge.

RESULTS

The following results were obtained: (1) Inflammatory factor levels in patients with CVT were higher than those in the controls. (2) Inflammatory factor levels in the acute and subacute stages were significantly higher than those in the chronic stage (all P < 0.05). (3) Serum NLR and CSF IgM levels were positively related to baseline degree of disability (odds ratio [OR], 1.279, 95% confidence interval [CI] 1.009-1.621, P = 0.042; OR 1.402, 95% CI 1.036-1.896, P = 0.028). The Hs-CRP level was positively correlated with the baseline occurrence of seizure (OR 1.040, 95% CI 1.001-1.080, P = 0.043). The baseline serum NLR (r = 0.244, P = 0.017), CSF IgA (r = 0.615, P < 0.001), CSF IgM (r = 0.752, P < 0.001), and CSF IgG (r = 0.248, P = 0.015) levels were positively associated with NIHSS. (4) The baseline NLR was significantly associated with high risk of poor outcome at discharge (OR 1.339, 95% CI 1.097-1.784, P = 0.007). Moreover, the ROC showed that NLR ≥ 4.205 could better predict the poor outcome at discharge. The data were analyzed using SPSS.

CONCLUSIONS

Inflammation may develop after CVT and gradually decrease during the course. Inflammation was significantly correlated with severity on admission and short-term poor outcome at discharge in CVT.

Effects of the Aphanizomenon flos-aquae Extract (Klamin®) on a Neurodegeneration Cellular Model

Cyanobacteria have been recognized as a source of bioactive molecules to be employed in nutraceuticals, pharmaceuticals, and functional foods. An extract of Aphanizomenon flos-aquae (AFA), commercialized as Klamin®, was subjected to chemical analysis to determine its compounds. The AFA extract Klamin® resulted to be nontoxic, also at high doses, when administered onto LAN5 neuronal cells. Its scavenging properties against ROS generation were evaluated by using DCFH-DA assay, and its mitochondrial protective role was determined by JC-1 and MitoSOX assays. Klamin® exerts a protective role against beta amyloid- (Aβ-) induced toxicity and against oxidative stress. Anti-inflammatory properties were demonstrated by NFβB nuclear localization and activation of IL-6 and IL-1β inflammatory cytokines through ELISA. Finally, by using thioflavin T (ThT) and fluorimetric measures, we found that Klamin® interferes with Aβ aggregation kinetics, supporting the formation of smaller and nontoxic structures compared to toxic Aβ aggregates alone. Altogether, these data indicate that the AFA extract may play a protective role against mechanisms leading to neurodegeneration.

A Natural Dietary Supplement with a Combination of Nutrients Prevents Neurodegeneration Induced by a High Fat Diet in Mice

Obesity and metabolic disorders can be risk factors for the onset and development of neurodegenerative diseases. The aim of the present study was to investigate the protective effects of a natural dietary supplement (NDS), containing Curcuma longa, silymarin, guggul, chlorogenic acid and inulin, on dysmetabolism and neurodegeneration in the brains of high fat diet (HFD)-fed mice. Decrease in the expression of FACL-4, CerS-1, CerS-4, cholesterol concentration and increase in the insulin receptor expression and insulin signaling activation, were found in brains of NDS-treated HFD brains in comparison with HFD untreated-mice, suggesting that NDS is able to prevent brain lipid accumulation and central insulin resistance. In the brains of NDS-treated HFD mice, the levels of RNS, ROS and lipid peroxidation, the expression of p-ERK, H-Oxy, i-NOS, HSP60, NF-kB, GFAP, IL-1β, IL-6 and CD4 positive cell infiltration were lower than in untreated HFD mice, suggesting antioxidant and anti-inflammatory effects of NDS. The decreased expression of p-ERK and GFAP in NDS-treated HFD mice was confirmed by immunofluorescence. Lastly, a lower number of apoptotic nuclei was found in cortical sections of NDS-treated HFD mice. The present data indicate that NDS exerts neuroprotective effects in HFD mice by reducing brain fat accumulation, oxidative stress and inflammation and improving brain insulin resistance.

Neuroprotection through flavonoid: Enhancement of the glyoxalase pathway

The glyoxalase pathway functions to detoxify reactive dicarbonyl compounds, most importantly methylglyoxal. The glyoxalase pathway is an antioxidant defense mechanism that is essential for neuroprotection. Excessive concentrations of methylglyoxal have deleterious effects on cells, leading to increased levels of inflammation and oxidative stress. Neurodegenerative diseases - including Alzheimer's, Parkinson's, Aging and Autism Spectrum Disorder - are often induced or exacerbated by accumulation of methylglyoxal. Antioxidant compounds possess several distinct mechanisms that enhance the glyoxalase pathway and function as neuroprotectants. Flavonoids are well-researched secondary plant metabolites that appear to be effective in reducing levels of oxidative stress and inflammation in neural cells. Novel flavonoids could be designed, synthesized and tested to protect against neurodegenerative diseases through regulating the glyoxalase pathway.

Blood-brain barrier breakdown in Alzheimer disease and other neurodegenerative disorders

The blood-brain barrier (BBB) is a continuous endothelial membrane within brain microvessels that has sealed cell-to-cell contacts and is sheathed by mural vascular cells and perivascular astrocyte end-feet. The BBB protects neurons from factors present in the systemic circulation and maintains the highly regulated CNS internal milieu, which is required for proper synaptic and neuronal functioning. BBB disruption allows influx into the brain of neurotoxic blood-derived debris, cells and microbial pathogens and is associated with inflammatory and immune responses, which can initiate multiple pathways of neurodegeneration. This Review discusses neuroimaging studies in the living human brain and post-mortem tissue as well as biomarker studies demonstrating BBB breakdown in Alzheimer disease, Parkinson disease, Huntington disease, amyotrophic lateral sclerosis, multiple sclerosis, HIV-1-associated dementia and chronic traumatic encephalopathy. The pathogenic mechanisms by which BBB breakdown leads to neuronal injury, synaptic dysfunction, loss of neuronal connectivity and neurodegeneration are described. The importance of a healthy BBB for therapeutic drug delivery and the adverse effects of disease-initiated, pathological BBB breakdown in relation to brain delivery of neuropharmaceuticals are briefly discussed. Finally, future directions, gaps in the field and opportunities to control the course of neurological diseases by targeting the BBB are presented.

MiRNAs of peripheral blood as the biomarker of schizophrenia

The diagnosis of schizophrenia is currently based on the symptoms and bodily signs rather than on the pathological and physiological markers of the patient. In the search for new molecular targeted therapy medicines, and recurrence of early-warning indicators have become the major focus of contemporary research, because they improve diagnostic accuracy. Biomarkers reflect the physiological, physical and biochemical status of the body, and so have extensive applicability and practical significance. The ascertainment of schizophrenia biomarkers will help diagnose, stratify of disease, and treat of schizophrenia patients. The detection of biomarkers from blood has become a promising area of schizophrenia research. Recently, a series of studies revealed that, MiRNAs play an important role in the genesis of schizophrenia, and their abnormal expressions have the potential to be used as biomarkers of schizophrenia. This article presents and summarizes the value of peripheral blood miRNAs with abnormal expression as the biomarker of schizophrenia.

Flavonoid Enhances the Glyoxalase Pathway in Cerebellar Neurons to Retain Cellular Functions

Oxidative stress is damaging to cells and contributes to aging and neurodegenerative disease. This state is mediated by production of imbalanced molecules, and reactive dicarbonyl compounds - mainly methylglyoxal. The glyoxalase pathway is an antioxidant defense system utilized to detoxify methylglyoxal and neutralize free radicals. Pathway dysfunction leads to overproduction and accumulation of toxic, prooxidant compounds. We hypothesize flavonoid treatment as a means to enhance the glyoxalase pathway’s ability to detoxify in neurons. This study found that flavonoid treatment in methylglyoxal treated cerebellar neurons increased the functioning of glyoxalase pathway by enhancing expression of glyoxalase-1 and glyoxalase-2 proteins, decreased cell death and increased cellular viability. Flavonoids also significantly contributed in the retention of synaptic functions (VGLUT1 and GAD65) in cerebellar neurons. In addition, flavonoids were found to be involved in pAkt - NF-κB signaling pathway through a reduction in phosphorylation of Akt. The data here show flavonoid compounds have the potential to protect the brain from aging and neurodegenerative disease.

Physio-pharmacological Investigations About the Anti-inflammatory and Antinociceptive Efficacy of (+)-Limonene Epoxide

D-limonene epoxidation generates (+)-limonene epoxide, an understudied compound in the pharmacologically point of view. Herein, we investigated the anti-inflammatory and antinociceptive potentialities of (+)-limonene epoxide and suggested a mechanism of action. The anti-inflammatory potential was analyzed using agents to induce paw edema, permeability, and myeloperoxidase (MPO) activity. Pro-inflammatory cytokines and cell migration of peritoneal cells were also assessed. Antinociceptive effects were evaluated by writhing test induced by acetic acid, formalin, and hot plate assays and contribution of opioid pathways. Pretreated animals with (+)-limonene epoxide showed reduced carrageenan-induced paw edema in all doses (25, 50, and 75 mg/kg) (P < 0.05). At 75 mg/kg, it suppressed edema provoked by compound 48/80, histamine, prostaglandin E₂, and serotonin and reduced permeability determined by Evans blue and MPO activity. It also reduced leukocytes, neutrophils, and IL-1β levels in the peritoneal cavity in comparison with carrageenan group (P < 0.05). (+)-Limonene epoxide diminished abdominal contortions induced by acetic acid (78.9%) and paw licking times in both 1 (41.8%) and 2 (51.5%) phases and a pretreatment with naloxone (3 mg/kg) reverted the antinociceptive action in morphine- and (+)-limonene epoxide-treated groups (P < 0.05). Additionally, it enlarged response times to the thermal stimulus after 60 and 90 min. In conclusion, (+)-limonene epoxide inhibited release/activity of inflammatory mediators, vascular permeability, migration of neutrophils and displayed systemic and peripheral analgesic-dependent effects of the opioid system.

A Shotgun Proteomics Approach Reveals a New Toxic Role for Alzheimer's Disease Aβ Peptide: Spliceosome Impairment

Proteomic changes have been described in many neurodegenerative diseases, including Alzheimer's disease (AD). However, the early events in the onset of the pathology are yet to be fully elucidated. A cell model system in which LAN5 neuroblastoma cells were incubated for a short time with a recombinant form of Aβ₄₂ was utilized. Proteins extracted from these cells were subjected to shotgun proteomics analysis by LTQ-Orbitrap-MS followed by label-free quantitation. By bioinformatics tools we found that the most significant of those found to be up-regulated were related to cytoskeletal dynamics (Rho related) and membrane-related processes. The most significant of the down-regulated proteins were hnRNP-related. In particular, hnRNPs involved in ribosomal biogenesis and in splicing were down-regulated. The latter of these processes stood out as it was highlighted ubiquitously and with the highest significance in the results of every analysis. Furthermore, our findings revealed down-regulation at every stage of the splicing process through down-regulation of every subunit of the spliceosome. Dysregulation of the spliceosome was also confirmed using a Western blot. In conclusion, these data suggest dysregulation of the proteins and processes identified as early events in pathogenesis of AD following Aβ accumulation.

A Novel Immunosuppressor, (5R)-5-Hydroxytriptolide, Alleviates Movement Disorder and Neuroinflammation in a 6-OHDA Hemiparkinsonian Rat Model

Parkinson's disease (PD) is one of the most common age-related neurodegenerative diseases. Promising therapies for PD still need to be explored. Immune dysfunction has been found to be involved in PD pathogenesis. Here, a novel immunosuppressor, (5R)-5-hydroxytriptolide (LLDT8), was used to treat 6-hydroxydopamine (6-OHDA)-induced hemiparkinson rats. We found that oral administration of LLDT8 significantly alleviated apomorphine-induced rotations at a dose of 125 µg/kg, and improved performance in cylinder and rotarod tests at a lower dose of 31.25 µg/kg, in 6-OHDA hemiparkinsonian rats. Moreover, loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) of the 6-OHDA rat was attenuated in response to LLDT8 treatment in a dose-dependent manner. In addition, inflammatory factors IL-1β, IL-6 and TNF-α, were significantly inhibited in LLDT8-treated hemiparkisonian rats, compared with vehicle. Notably, the level of dopamine (DA) in the striatum of PD rats was restored by LLDT8 treatment. Furthermore, we also detected that the disequilibrium of peripheral lymphocytes was reversed by LLDT8 administration. Taken together, the results imply that the immunosuppressor, LLDT8, can rescue dopaminergic neurodegeneration in 6-OHDA hemiparkinsonian rats, thus providing a potential therapeutic strategy for PD.

Arabidopsis thaliana extracts optimized for polyphenols production as potential therapeutics for the APOE-modulated neuroinflammation characteristic of Alzheimer's disease in vitro

Although the cause of Alzheimer's disease (AD) is unknown, glial-induced neuroinflammation is an early symptom. Familial AD is caused by increases in amyloid-beta (Aβ) peptide, particularly soluble oligomeric (oAβ), considered a proximal neurotoxin and neuroinflammatory stimuli. APOE4, a naturally occurring genotype of APOE, is the greatest genetic risk factor for AD; increasing risk up to 12-fold compared to APOE3 and APOE2. oAβ-induced neuroinflammation is greater with APOE4 compared to APOE3 and APOE2. As sinapates and flavonoids have anti-inflammatory properties, a protocol was developed for optimizing polyphenol production in seedlings of Arabidopsis thaliana (A. thaliana). Three mutants (cop1, prn1, xpf3) were identified, and the extracts treated with liver microsomes to mimic physiological metabolism, with HPLC and MS performed on the resulting metabolites for peak identification. These extracts were used to treat primary glial cells isolated from human APOE-targeted-replacement (APOE-TR) and APOE-knock-out (KO) mice, with neuroinflammation induced by lipopolysaccharide (LPS) or oAβ. The dose-response data for TNFα secretion demonstrate the followed the order: APOE-KO > APOE4 > APOE3 > APOE2, with xpf3 the most effective anti-neuroinflammatory across APOE genotypes. Thus, the plant-based approach described herein may be particularly valuable in treating the APOE4-induced neuroinflammatory component of AD risk.

Biflavonoids as Potential Small Molecule Therapeutics for Alzheimer's Disease

Flavonoids are naturally occurring phytochemicals found in a variety of fruits and vegetables and offer color, flavor, aroma, nutritional and health benefits. Flavonoids have been found to play a neuroprotective role by inhibiting and/or modifying the self-assembly of the amyloid-β (Aβ) peptide into oligomers and fibrils, which are linked to the pathogenesis of Alzheimer's disease. The neuroprotective efficacy of flavonoids has been found to strongly depend on their structure and functional groups. Flavonoids may exist in monomeric, as well as di-, tri-, tetra- or polymeric form through C-C or C-O-C linkages. It has been shown that flavonoids containing two or more units, e.g., biflavonoids, exert greater biological activity than their respective monoflavonoids. For instance, biflavonoids have the ability to distinctly alter Aβ aggregation and more effectively reduce the toxicity of Aβ oligomers compared to the monoflavonoid moieties. Although the molecular mechanisms remain to be elucidated, flavonoids have been shown to alter the Aβ aggregation pathway to yield non-toxic, unstructured Aβ aggregates, as well as directly exerting a neuroprotective effect to cells. In this chapter, we review biflavonoid-mediated Aβ aggregation and toxicity, and highlight the beneficial roles biflavonoids can potentially play in the prevention and treatment of Alzheimer's disease.

APOE-modulated Aβ-induced neuroinflammation in Alzheimer's disease: current landscape, novel data, and future perspective

Chronic glial activation and neuroinflammation induced by the amyloid-β peptide (Aβ) contribute to Alzheimer's disease (AD) pathology. APOE4 is the greatest AD-genetic risk factor; increasing risk up to 12-fold compared to APOE3, with APOE4-specific neuroinflammation an important component of this risk. This editorial review discusses the role of APOE in inflammation and AD, via a literature review, presentation of novel data on Aβ-induced neuroinflammation, and discussion of future research directions. The complexity of chronic neuroinflammation, including multiple detrimental and beneficial effects occurring in a temporal and cell-specific manner, has resulted in conflicting functional data for virtually every inflammatory mediator. Defining a neuroinflammatory phenotype (NIP) is one way to address this issue, focusing on profiling the changes in inflammatory mediator expression during disease progression. Although many studies have shown that APOE4 induces a detrimental NIP in peripheral inflammation and Aβ-independent neuroinflammation, data for APOE-modulated Aβ-induced neuroinflammation are surprisingly limited. We present data supporting the hypothesis that impaired apoE4 function modulates Aβ-induced effects on inflammatory receptor signaling, including amplification of detrimental (toll-like receptor 4-p38α) and suppression of beneficial (IL-4R-nuclear receptor) pathways. To ultimately develop APOE genotype-specific therapeutics, it is critical that future studies define the dynamic NIP profile and pathways that underlie APOE-modulated chronic neuroinflammation. In this editorial review, we present data supporting the hypothesis that impaired apoE4 function modulates Aβ-induced effects on inflammatory receptor signaling, including amplification of detrimental (TLR4-p38α) and suppression of beneficial (IL-4R-nuclear receptor) pathways, resulting in an adverse NIP that causes neuronal dysfunction. NIP, Neuroinflammatory phenotype; P.I., pro-inflammatory; A.I., anti-inflammatory.

Age-related macular degeneration: insights into inflammatory genes

Age-related macular degeneration (AMD) is a progressive neurodegenerative disease that affects approximately 8.7% of elderly people worldwide (>55 years old). AMD is characterized by a multifactorial aetiology that involves several genetic and environmental risk factors (genes, ageing, smoking, family history, dietary habits, oxidative stress, and hypertension). In particular, ageing and cigarette smoking (including oxidative compounds and reactive oxygen species) have been shown to significantly increase susceptibility to the disease. Furthermore, different genes (CFH, CFI, C2, C3, IL-6, IL-8, and ARMS2) that play a crucial role in the inflammatory pathway have been associated with AMD risk. Several genetic and molecular studies have indicated the participation of inflammatory molecules (cytokines and chemokines), immune cells (macrophages), and complement proteins in the development and progression of the disease. Taking into consideration the genetic and molecular background, this review highlights the genetic role of inflammatory genes involved in AMD pathogenesis and progression.

Evidence linking oxidative stress, mitochondrial dysfunction, and inflammation in the brain of individuals with autism

Autism spectrum disorders (ASDs) are a heterogeneous group of neurodevelopmental disorders that are defined solely on the basis of behavioral observations. Therefore, ASD has traditionally been framed as a behavioral disorder. However, evidence is accumulating that ASD is characterized by certain physiological abnormalities, including oxidative stress, mitochondrial dysfunction and immune dysregulation/inflammation. While these abnormalities have been reported in studies that have examined peripheral biomarkers such as blood and urine, more recent studies have also reported these abnormalities in brain tissue derived from individuals diagnosed with ASD as compared to brain tissue derived from control individuals. A majority of these brain tissue studies have been published since 2010. The brain regions found to contain these physiological abnormalities in individuals with ASD are involved in speech and auditory processing, social behavior, memory, and sensory and motor coordination. This manuscript examines the evidence linking oxidative stress, mitochondrial dysfunction and immune dysregulation/inflammation in the brain of ASD individuals, suggesting that ASD has a clear biological basis with features of known medical disorders. This understanding may lead to new testing and treatment strategies in individuals with ASD.