Alzheimer’s disease and cytokine IL-10 gene polymorphisms: is there an association?

The involvement of neuroinflammation in an animal model of dementia and depression

Alzheimer's disease (AD) and depression are inflammatory pathologies, leading to increased inflammatory response and neurotoxicity. Therefore, this study aimed to evaluate the effect of the treatment with fluoxetine and/or galantamine and/or donepezil on the levels of proinflammatory and anti-inflammatory cytokines in a mixed animal model of depression and dementia. Adult male Wistar rats underwent chronic mild stress (CMS) protocol for 40 days and were subjected to stereotaxic surgery for intra-hippocampal administration of amyloid-beta (Aꞵ) peptide or artificial cerebrospinal fluid (ACSF) to mimic the dementia animal model. On the 42nd day, animals were treated with water, galantamine, donepezil, and/or fluoxetine, orally for 17 days. On the 57th and 58th days, the Splash and Y-maze tests for behavior analysis were performed. The frontal cortex and hippocampus were used to analyze the tumor necrosis factor alfa (TNF-α), interleukin 1 beta (IL-1ꞵ), IL-6, and IL-10 levels. The results of this study show that animals subjected to CMS and administration of Aꞵ had anhedonia, cognitive impairment, increased TNF-α and IL-1ꞵ levels in the frontal cortex, and reduced IL-10 levels in the hippocampus. All treatment groups were able to reverse the cognitive impairment. Only donepezil did not decrease the TNF-α levels in the hippocampus. Fluoxetine + galantamine and fluoxetine + donepezil reversed the anhedonia. Fluoxetine reversed the anhedonia and IL-1ꞵ levels in the frontal cortex. In addition, fluoxetine + donepezil reversed the reduction of IL-10 levels in the hippocampus. The results indicate a pathophysiological interaction between AD and depression, and the association of medications in the future may be a possible therapeutic strategy to reduce inflammation, especially the fluoxetine-associated treatments.

Taming Microglia in Alzheimer's Disease: Exploring Potential Implications of Choline Alphoscerate via α7 nAChR Modulation

Alzheimer's disease (AD), marked by cognitive impairment, predominantly affects the brain regions regulated by cholinergic innervation, such as the cerebral cortex and hippocampus. Cholinergic dysfunction, a key contributor to age-related cognitive decline, has spurred investigations into potential therapeutic interventions. We have previously shown that choline alphoscerate (α-GPC), a cholinergic neurotransmission-enhancing agent, protects from Aβ-mediated neurotoxicity. Herein, we investigated the effects of α-GPC on the microglial phenotype in response to Aβ via modulation of the nicotinic alpha-7 acetylcholine receptor (α7 nAChR). BV2 microglial cells were pre-treated for 1 h with α-GPC and were treated for 24, 48, and 72 h with Aβ1-42 and/or α-BTX, a selective α7nAchR antagonist. Fluorescent immunocytochemistry and Western blot analysis showed that α-GPC was able to antagonize Aβ-induced inflammatory effects. Of note, α-GPC exerted its anti-inflammatory effect by directly activating the α7nAChR receptor, as suggested by the induction of an increase in [Ca2+]i and Ach-like currents. Considering that cholinergic transmission appears crucial in regulating the inflammatory profiles of glial cells, its modulation emerges as a potential pharmaco-therapeutic target to improve outcomes in inflammatory neurodegenerative disorders, such as AD.

Alzheimer's Disease-Related Proteins Targeted by Secondary Metabolite Compounds from Streptomyces: A Scoping Review

Background

Alzheimer's disease (AD) is a neurodegenerative disease that is characterized as rapid and progressive cognitive decline affecting 26 million people worldwide. Although immunotherapies are ideal, its clinical safety and effectiveness are controversial, hence, treatments are still reliant on symptomatic medications. Concurrently, the Streptomyces genus has attracted attention given its pharmaceutically beneficial secondary metabolites to treat neurodegenerative diseases.

Objective

To present secondary metabolites from Streptomyces sp. with regulatory effects on proteins and identified prospective target proteins for AD treatment.

Methods

Research articles published between 2010 and 2021 were collected from five databases and 83 relevant research articles were identified. Post-screening, only 12 research articles on AD-related proteins were selected for further review. Bioinformatics analyses were performed through the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) network, PANTHER Go-Slim classification system (PANTHER17.0), and Kyoto Encyclopedia of Genes and Genomes (KEGG) Mapper.

Results

A total of 20 target proteins were identified from the 12 shortlisted articles. Amyloid-β, BACE1, Nrf-2, Beclin-1, and ATG5 were identified as the potential target proteins, given their role in initiating AD, mitigating neuroinflammation, and autophagy. Besides, 10 compounds from Streptomyces sp., including rapamycin, alborixin, enterocin, bonnevillamides D and E, caniferolide A, anhydroexfoliamycin, rhizolutin, streptocyclinone A and B, were identified to exhibit considerable regulatory effects on these target proteins.

Conclusions

The review highlights several prospective target proteins that can be regulated through treatments with Streptomyces sp. compounds to prevent AD's early stages and progression. Further identification of Streptomyces sp. compounds with potential anti-AD properties is recommended.

Stress regulates Alzheimer's disease progression via selective enrichment of CD8+ T cells

This study investigates stress's impact on Alzheimer's disease (AD) using male APP/PS1 transgenic mice. Negative stressors (chronic social defeat, restraint) and positive hedonia (environmental enrichment, EE) were applied. Stress worsens AD pathology, while EE slows progression. Brain RNA sequencing reveals interleukin-6 (IL-6) and IL-10 as key stress-related AD regulators. Flow cytometry shows that the CD8+/CD4+ T cell ratio shifts in response to stress exposure and EE. Stress exposure increases CD8+/CD4+ ratio, opposite to EE. Depletion and enrichment of CD8+ T cells both accelerate AD, indicating immune intervention's negative impact. Stress management and balanced immunity may aid AD therapy, highlighting novel potential treatment.

Role of pro-inflammatory cytokines in Alzheimer's disease and neuroprotective effects of pegylated self-assembled nanoscaffolds

Neurodegeneration and synaptic loss in Alzheimer's disease (AD) lead to impairment in memory functions. Neuroinflammation causes activation of microglia and astrocytes cells that locally and systemically produces inflammatory cytokines which can serve as early diagnostic markers or therapeutic targets in AD. Pro-inflammatory cytokines (Interleukins (IL-1β, IL-6 and IL-10) and tumor necrosis factor (TNF α)) levels were estimated in serum, cerebral tissue, hepatic tissue, and renal tissue in treatment groups of scopolamine-induced amnesia mice model using ELISA protocol. The results showed that cerebral tissue of AD mice exhibited elevated levels of IL1β, IL6, IL10 and TNFα which indicate contribution of pro-inflammatory cytokines in the progression of AD. A significant reduction in the concentration of IL1β, IL-10 and TNF-α were noticed in serum, cerebral tissue and hepatic tissue of animal group treated with marketed memantine tablet (Admenta), pure memantine drug (MEMp), memantine-poly (lactic-co-glycolic acid) self-assembled nanoscaffolds (MEM-PLGA) SANs, Polyethylene Glycol coated memantine-poly (lactic-co-glycolic acid) self-assembled nanoscaffolds [(PEG-MEM-PLGA) SANs] and Polyethylene Glycol coated memantine-poly [(lactic-co-glycolic acid)] self-assembled nanoscaffolds grafted with Bone Marrow Derived Stem Cell ((PEG-MEM-PLGA) SANs-BMSc), whereas a high level of IL-6 was observed in hepatic tissue, cerebral tissue and renal tissues of normal and AD induced mice which showed the emerging potential of IL-6 cytokines that can trigger either neurons survival after injury or causing neurodegeneration and cell apoptosis. The Neuroregenerative potential of stem cells helps in the proliferation of neuronal cell and thus improves cognition in AD animal model.

Analysis of Correlation between Serum Inflammatory Factors and Cognitive Function, Language, and Memory in Alzheimer’s Disease and Its Clinical Significance

Objective

A case-control study was conducted to explore the correlation between serum inflammatory factor monitoring and cognitive function, language, and memory ability of Alzheimer's disease (AD) and its clinical significance.

Methods

Thirty-six patients with AD treated from April 2019 to August 2021 in our hospital were enrolled as the study subjects (AD group), and 30 healthy volunteers from the physical examination center and the AD group with the same sex, age, education, and no complaints of memory loss were enrolled as the control group. Montreal Cognitive Assessment (MoCA) and AD Rating Scale-Cognitive (ADAS-cog) were employed to assess the cognitive function of AD and the control group. The Chinese Standard aphasia Test of China Rehabilitation Research Center (CRRCAE) was employed to assess the language function of AD and NC population. The World Health Organization-University of California, Los Angeles Auditory Word Learning Test (WHO-UCLAAV-LT) scale was employed to evaluate the memory function of AD group and control group. The levels of inflammatory factors in serum of the AD group and control group were detected by enzyme-linked immunosorbent assay (ELISA). The serum inflammatory factors levels were compared between the AD group and the control group, and the correlation between the level of serum inflammatory factors and cognitive function, language, and memory ability in the AD group was analyzed.

Results

In terms of the demographic data of the two groups, there exhibited no significant difference in gender, age, education level, and other general data (P > 0.05). In terms of cognitive function, MoCA scores were remarkably lower compared to the AD group. In the comparison of memory ability, the scores of long-term delayed recognition, delayed memory, and instantaneous memory in the AD group were remarkably lower (P < 0.05). In the comparison of language ability, the scores of listening comprehension, reading, and naming in the AD group exhibited remarkably lower (P < 0.05). With regard to the levels of serum inflammatory factors, the levels of serum interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α), and CCL-12 in AD group were remarkably higher, while the level of TNF-β in the AD group was lower compared to the control group. Furthermore, there exhibited no significant correlation between the levels of serum IL-4, IL-6, IL-10, TNF-α, CCL-2, and the total scores, MoCA, and ADAS-cog, but there exhibited a positive relationship between the level of serum TNF-β and the score of MoCA scale. The correlations between IL-4, IL-6, IL-10, TNF-α, TNF-β, CCL-2, and the scores of long-term delayed recognition, delayed memory, and instantaneous memory were analyzed in the AD group. The serum levels of IL-4, IL-6, IL-10, TNF-α, CCL-2, and TNF-β were not remarkably correlated with the scores of long-term delayed recognition, delayed memory, and instantaneous memory. The correlations between IL-4, IL-6, IL-10, TNF-α, TNF-β, CCL-2, and the scores of listening comprehension, reading, and naming were analyzed in the AD group, but with no significant correlation between the serum levels of IL-4, IL-6, IL-10, CCL-2, TNF-α, and TNF-β and the scores of listening comprehension, reading, and naming.

Conclusion

Compared with the control group, the levels of serum IL-4, IL-6, IL-10, TNF-α, and CCL-2 in patients with AD exhibited remarkably higher, while the level of serum TNF-β exhibited remarkably lower. The level of serum TNF-β was remarkably correlated with cognitive function in patients with AD, which may reflect the severity of cognitive impairment in patients with AD.

In-silico analysis unravels the structural and functional consequences of non-synonymous SNPs in the human IL-10 gene

Background

Interleukin-10 (IL-10) is an anti-inflammatory cytokine that affects different immune cells. It is also associated with the stimulation of the T and B cells for the production of antibodies. Several genetic polymorphisms in the IL-10 gene have been reported to cause or aggravate certain diseases like inflammatory bowel disease, rheumatoid arthritis, systemic sclerosis, asthma, etc. However, the disease susceptibility and abnormal function of the mutated IL-10 variants remain obscure.

Results

In this study, we used seven bioinformatics tools (SIFT, PROVEAN, PMut, PANTHER, PolyPhen-2, PHD-SNP, and SNPs&GO) to predict the disease susceptible non-synonymous SNPs (nsSNPs) of IL-10. Nine nsSNPs of IL-10 were predicted to be potentially deleterious: R42G, R45Q, F48L, E72G, M95T, A98D, R125S, Y155C, and I168T. Except two, all of the putative deleterious mutations are found in the highly conserved region of IL-10 protein structure, thus affecting the protein's stability. The 3-D structure of mutant proteins was modeled by project HOPE, and the protein–protein interactions were assessed with STRING. The predicted nsSNPs: R42Q, R45Q, F48L, E72G, and I168T are situated in the binding site region of the IL-10R1 receptor. Disruption of binding affinity with its receptor leads to deregulation of the JAK-STAT pathway and results in enhanced inflammation that imbalance in cellular signaling. Finally, Kaplan–Meier Plotter analysis displayed that deregulation of IL-10 expression affects gastric and ovarian cancer patients' survival rate. Thus, IL-10 could be useful as a potential prognostic marker gene for some cancers.

Conclusion

This study has determined the deleterious nsSNPs of IL-10 that might contribute to the malfunction of IL-10 protein and ultimately lead to the IL-10 associated diseases.

The Potential Role of Cytokines and Growth Factors in the Pathogenesis of Alzheimer's Disease

Alzheimer's disease (AD) is one of the most prominent neurodegenerative diseases, which impairs cognitive function in afflicted individuals. AD results in gradual decay of neuronal function as a consequence of diverse degenerating events. Several neuroimmune players (such as cytokines and growth factors that are key players in maintaining CNS homeostasis) turn aberrant during crosstalk between the innate and adaptive immunities. This aberrance underlies neuroinflammation and drives neuronal cells toward apoptotic decline. Neuroinflammation involves microglial activation and has been shown to exacerbate AD. This review attempted to elucidate the role of cytokines, growth factors, and associated mechanisms implicated in the course of AD, especially with neuroinflammation. We also evaluated the propensities and specific mechanism(s) of cytokines and growth factors impacting neuron upon apoptotic decline and further shed light on the availability and accessibility of cytokines across the blood-brain barrier and choroid plexus in AD pathophysiology. The pathogenic and the protective roles of macrophage migration and inhibitory factors, neurotrophic factors, hematopoietic-related growth factors, TAU phosphorylation, advanced glycation end products, complement system, and glial cells in AD and neuropsychiatric pathology were also discussed. Taken together, the emerging roles of these factors in AD pathology emphasize the importance of building novel strategies for an effective therapeutic/neuropsychiatric management of AD in clinics.

Effects of Cancer, Chemotherapy, and Cytokines on Subjective and Objective Cognitive Functioning Among Patients with Breast Cancer

Simple Summary

Although cognitive impairments have been complained about in patients with breast cancer who underwent chemotherapy, recent research has described possible neurocognitive decline prior to the start of chemotherapy and suggested that inflammatory cytokines may also have been involved. However, inconsistencies have been found in correlations of cognitive impairments with cancer, chemotherapy, and peridiagnostic cytokine levels. This cross-sectional study aimed to examine associations of cognitive functions and levels of cytokines in patients with newly- diagnosed breast cancer before chemotherapy, those that were 3 to 9 months after completing chemotherapy, and non-cancer controls, adjusting for baseline intelligence quotient, mood, and fatigue. We found that the performance in semantic association of verbal fluency in patients post chemotherapy might be affected by the status of cancer, IL-13, and anxiety. Our results indicated that verbal fluency and anxiety may be important when considering relevant psychosocial managements or prophylactic interventions for cognitive preservation associated with regulations in cytokines.

Abstract

Background: We aimed to investigate the associations of breast cancer (BC) and cancer-related chemotherapies with cytokine levels, and cognitive function. Methods: We evaluated subjective and objective cognitive function in BC patients before chemotherapy and 3~9 months after the completion of chemotherapy. Healthy volunteers without cancer were also compared as control group. Interleukins (IL) 2, 4, 5, 6, 10, 12p70, 13, 17A, 1β, IFNγ, and TNFα were measured. Associations of cancer status, chemotherapy and cytokine levels with subjective and objective cognitive impairments were analyzed using a regression model, adjusting for covariates, including IQ and psychological distress. Results: After adjustment, poorer performance in semantic verbal fluency was found in the post-chemotherapy subgroup compared to controls (p = 0.011, η² = 0.070); whereas pre-chemotherapy patients scored higher in subjective cognitive perception. Higher IL-13 was associated with lower semantic verbal fluency in the post-chemotherapy subgroup. Higher IL-10 was associated with better perceived cognitive abilities in the pre-chemotherapy and control groups; while IL-5 and IL-13 were associated with lower perceived cognitive abilities in pre-chemotherapy and control groups. Our findings from mediation analysis further suggest that verbal fluency might be affected by cancer status, although mediated by anxiety. Conclusions: Our findings suggest that verbal fluency might be affected by cancer status, although mediated by anxiety. Different cytokines and their interactions may have different roles of neuroinflammation or neuroprotection that need further research.

IL-1β, IL-6, IL-10, and TNFα Single Nucleotide Polymorphisms in Human Influence the Susceptibility to Alzheimer's Disease Pathology

BACKGROUND

Neuroinflammation plays an important role in Alzheimer's disease (AD). During this process, activated microglia release pro-inflammatory cytokines such as interleukin (IL)-1α, IL-1β, IL-6, and tumor necrosis factor α (TNFα) that participate in neuron damage, but also anti-inflammatory cytokines (such as IL-10), which maintain homeostasis of immune response. Previous studies showed the association of IL-1α -889C/T (rs1800587), IL-1β-1473G/C (rs1143623), IL-6 -174C/G (rs1800795), IL-10 -1082G/A (rs1800896), and TNFα -308A/G (rs1800629) polymorphisms with AD.

OBJECTIVE

We aimed to investigate whether people with certain IL-1α, IL-1β, IL-6, IL-10, and TNFα genotypes in these polymorphisms are more prone to develop AD-related pathology, reflected by pathological levels of cerebrospinal fluid (CSF) AD biomarkers including amyloid-β1-42, total tau (t-tau), tau phosphorylated at Thr 181 (p-tau181), Ser 199 (p-tau199), and Thr 231 (p-tau231), and visinin-like protein 1 (VILIP-1).

METHODS

The study included 115 AD patients, 53 patients with mild cognitive impairment, and 11 healthy controls. The polymorphisms were determined using real-time polymerase chain reaction. Levels of CSF biomarkers were determined by enzyme-linked immunosorbent assay.

RESULTS

A significant increase in p-tau CSF levels was found in patients with the AA IL-10 -1082G/A and GG TNFα -308A/G genotypes, and in carriers of a G allele in IL-1β -1473C/G and IL-6 -174C/G polymorphisms. t-tau levels were increased in carriers of a G allele in IL-1β -1473C/G polymorphism. An increase in VILIP-1 levels was observed in patients with CG and GG IL-1β -1473C/G, GC IL-6 -174C/G, and GG TNFα -308A/G genotype.

CONCLUSION

These results suggest that persons carrying certain genotypes in IL10 (-1082G/A), IL1β (1473C/G), IL6 (-174C/G), and TNFIα (-308A/G) could be more vulnerable to development of neuroinflammation, and consequently of AD.

Hydroxychloroquine Increased Anxiety-Like Behaviors and Disrupted the Expression of Some Related Genes in the Mouse Brain

Hydroxychloroquine (HCQ), which has been proposed as a therapeutic or prophylactic drug for COVID-19, has been administered to thousands of individuals with varying efficacy; however, our understanding of its adverse effects is insufficient. It was reported that HCQ induced psychiatric symptoms in a few patients with autoimmune diseases, but it is still uncertain whether HCQ poses a risk to mental health. Therefore, in this study, we treated healthy mice with two different doses of HCQ that are comparable to clinically administered doses for 7 days. Psychiatric-like behaviors and the expression of related molecules in the brain were evaluated at two time points, i.e., 24 h and 10 days after drug administration. We found that HCQ increased anxiety behavior at both 24 h and 10 days. Furthermore, HCQ decreased the mRNA expression of interleukin-1beta, corticotropin-releasing hormone (Crh), a serotonin transporter (Slc6a4), and a microglia maker (Aif1) in the hippocampus and decreased the mRNA expression of brain-derived neurotrophic factor (Bdnf) in both the hippocampus and amygdala. Lots of these behavioral and molecular changes were sustained beyond 10 days after drug administration, and some of them were dose-dependent. Although this animal study does not prove that HCQ has a similar effect in humans, it indicates that HCQ poses a significant risk to mental health and suggests that further clinical investigation is essential. According to our data, we recommend that HCQ be carefully used as a prophylactic drug in people who are susceptible to mental disorders.

The interactive effect of genetic polymorphisms of IL-10 and COMT on cognitive function in schizophrenia

Dopaminergic and inflammatory systems have been proven to play an important role in the cognitive deficits of schizophrenia. Although increasing evidence indicates two systems have strong interaction, the relevant research on this interaction is still limited. Catechol-o-methyltransferase (COMT) and Interleukin-10 (IL-10) play critical functions in dopaminergic and inflammatory systems respectively, and their genetic polymorphisms are both associated with cognitive function. However, the interactive effect of their genetic polymorphisms has not been investigated. In this study, COMT Val158Met (rs4680) and IL-10 -592A/C (rs1800872) polymorphisms were measured in patients with chronic schizophrenia (n = 244) and healthy controls (n = 396), and their cognitive functions were assessed using the "Repeatable Battery for the Assessment of Neuropsychological Status" (RBANS). We found that IL-10 alone had no effect on cognitive function, while COMT affected language ability and interacted with the schizophrenia (case vs control) or sex in multiple RBANS indexes. Additionally, we found there was a significant interactive effect between IL-10 and COMT polymorphisms on multiple cognitive indexes of RBANS. In detail, the analysis showed that the IL-10 polymorphism had opposite effects on cognitive function in different COMT genotype carriers; meanwhile, the polymorphism of COMT only had a significant effect on cognitive function in IL-10 C carriers. And this interaction was more significant in schizophrenia than in controls. Our study discovered for the first time, there is an interactive effect between IL-10 and COMT genetic polymorphisms on cognitive function, which is valuable for further investigations and drug administrations associated with both systems.

Interleukin-17 and Interleukin-10 Association with Disease Progression in Schizophrenia

BACKGROUND

Alteration in cytokine levels are known to be involved in the pathogenesis of schizophrenia.

OBJECTIVES

To estimate the serum levels of interleukin-17 (IL-17) and interleukin-10 (IL-10) and their association with disease progression in schizophrenia.

METHODS

A total of 67 schizophrenia cases were enrolled in the present study. IL-17 and IL-10 were estimated by enzyme-linked immunosorbent assay. Positive and Negative Syndrome Scale (PANSS) was used to evaluate disease severity.

RESULTS

IL-17 was positively correlated with positive symptom score (r = 0.256, p = .036), general psychopathology score (r = 0.255, p = .038) and total score (r = 0.273, p = .025) in schizophrenia. IL-17 and IL-10 were significantly increased in schizophrenia cases with PANSS more than 85 compared to those with 71-85.

CONCLUSION

IL-17 and IL-10 are associated with disease severity in schizophrenia but are not good markers for predicting the disease progression.

IL-35 polymorphisms and cognitive decline did not show any association in patients with coronary heart disease over a 2-year period: A retrospective observational study (STROBE compliant)

Prior evidence suggested that inflammation and inflammatory cytokines polymorphisms might be essential in the development of coronary heart disease (CHD) and cognitive decline. The following study investigated the associations between interleukin-35 (IL-35) polymorphisms and cognitive decline in CHD patients over a 2-year period.CHD patients were enrolled between January 2015 and January 2016. Cognitive function, including memory, orientation, verbal and attention were assessed using Telephone Interview for Cognitive Status-Modified (TICS-m) during a 2-year follow-up. Genotypes of the single nucleotide polymorphisms (SNPs), including rs2243115, rs568408, rs582054, rs583911, rs428253, rs4740 and rs393581 of IL-35 were examined by MassArray (Sequenom). The differences of TICS-m score between 2-year interval were used to estimate the cognitive decline; linear regression model was used to analyze the association between IL-35 polymorphisms and cognitive decline in CHD patients after a 2-year follow-up.The mean age of study individuals was 60.58 (±7.86) years old. There were 255 (68.5%) males and 117 (31.5%) female patients. The TICS-m scores, including overall cognition score, verbal attention and memory scores gradually decreased over a 2 year follow up period (P < .001, respectively), whereas there was no difference in orientation function score between the 1-year and 2-year follow-up (P = .448). Furthermore, after adjusting for age, sex, history of hypertension(HT) and Diabetes mellitus(DM), smoking, education, Therapy regimen (PCI, CABG, medication) left ventricular ejection fraction (LVEF), and the severity of coronary artery stenosis (Gensini score), no association was found between IL-35 rs2243115, rs568408, rs582054, rs583911, rs428253, rs4740 genotypes and cognitive decline in CHD patients over a 2-year period.Our data reveled that IL-35 polymorphisms was not associated with cognitive decline in CHD patients over a 2-year period. Yet, further studies are needed to confirm the role of cytokine gene polymorphisms in cognitive decline among CHD patients.

Microdose Lithium Treatment Reduced Inflammatory Factors and Neurodegeneration in Organotypic Hippocampal Culture of Old SAMP-8 Mice

It was already shown that microdoses of lithium carbonate (Li₂CO₃) promoted memory stabilization in humans and mice. Prolonged treatment also reduced neuronal loss and increased the density of the neurotrophin BDNF in transgenic mice for Alzheimer's disease. The aim of this study was to evaluate whether lithium ions affect inflammatory profiles and neuronal integrity in an animal model of accelerated senescence (SAMP-8). Organotypic hippocampal cultures obtained from 11 to 12-month-old SAMP-8 mice were treated with 2 µM, 20 µM and 200 µM Li₂CO₃. 2 µM Li₂CO₃ promoted a significant reduction in propidium iodide uptake in the CA2 area of hippocampus, whereas 20 µM promoted neuroprotection in the CA3 and GrDG areas. 200 µM caused an increase in cellular death, showing toxicity. Measured with quantitative PCR, IL-1α, IL-6 and MIP-1B/CCL-4 gene expression was significantly reduced with 20 µM Li₂CO₃, whereas IL-10 gene expression was significantly increased with the same concentration. In addition, 2 µM and 20 µM Li₂CO₃ were also effective in reducing the activation of NFkB and inflammatory cytokines densities, as evaluated by ELISA. It is concluded that very low doses of Li₂CO₃ can play an important role in neuroprotection as it can reduce neuronal loss and neuroinflammation in older individuals.

Anti-Inflammatory and Anti-Migratory Activities of Isoquinoline-1-Carboxamide Derivatives in LPS-Treated BV2 Microglial Cells via Inhibition of MAPKs/NF-κB Pathway

Eleven novel isoquinoline-1-carboxamides (HSR1101~1111) were synthesized and evaluated for their effects on lipopolysaccharide (LPS)-induced production of pro-inflammatory mediators and cell migration in BV2 microglial cells. Three compounds (HSR1101~1103) exhibited the most potent suppression of LPS-induced pro-inflammatory mediators, including interleukin (IL)-6, tumor necrosis factor-alpha, and nitric oxide (NO), without significant cytotoxicity. Among them, only N-(2-hydroxyphenyl) isoquinoline-1-carboxamide (HSR1101) was found to reverse LPS-suppressed anti-inflammatory cytokine IL-10, so it was selected for further characterization. HSR1101 attenuated LPS-induced expression of inducible NO synthase and cyclooxygenase-2. Particularly, HSR1101 abated LPS-induced nuclear translocation of NF-κB through inhibition of IκB phosphorylation. Furthermore, HSR1101 inhibited LPS-induced cell migration and phosphorylation of mitogen-activated protein kinases (MAPKs) including extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase, and p38 MAPK. The specific MAPK inhibitors, U0126, SP600125, and SB203580, suppressed LPS-stimulated pro-inflammatory mediators, cell migration, and NF-κB nuclear translocation, indicating that MAPKs may be the upstream kinase of NF-κB signaling. Collectively, these results demonstrate that HSR1101 is a potent and promising compound suppressing LPS-induced inflammation and cell migration in BV2 microglial cells, and that inhibition of the MAPKs/NF-κB pathway mediates its anti-inflammatory and anti-migratory effects. Based on our findings, HSR1101 may have beneficial impacts on various neurodegenerative disorders associated with neuroinflammation and microglial activation.

Association of IL-10 gene promoter polymorphisms with susceptibility to pseudoexfoliation syndrome, pseudoexfoliative and primary open-angle glaucoma

Background

The involvement of cytokines in pathogenesis of pseudoexfoliation syndrome and glaucoma has been demonstrated in several studies. The aim of the present study was to explore the association between three promoter polymorphisms −592C/A (rs1800872), − 819C/T (rs1800871) and -1082A/G (rs1800896) of interleukin 10 (IL-10) gene with susceptibility to pseudoexfoliation syndrome (PEX), pseudoexfoliative glaucoma (PEXG), and primary open-angle glaucoma (POAG).

Methods

In this study, 114 PEX, 118 PEXG, 114 POAG patients and 126 healthy individuals from Iranian population were participated. Detailed ophthalmic examinations by an ophthalmologist including slit-lamp bio-microscopic examination, dilated examination of the lens, gonioscopy, and funduscopy were carried out on patients and controls. Genomic DNA was extracted from the blood samples and ARMS–PCR was performed to detect promoter polymorphisms of IL-10.

Results

In all three SNPs studied, there was a significant difference in the genotype distribution between patients and control subjects. Results revealed that the AA genotype of IL-10 -592C/A SNP is associated with PEX. However, TT genotype of −819C/T and AA genotype of -1082A/G SNP are significantly associated with susceptibility to either PEX or PEXG and POAG disorders. Furthermore, the ACC haplotype containing the IL-10 -1082A allele was associated with PEX (P = 0.02, OR = 5.76, 95% CI = 5.17–24.49), PEXG (P = 0.006, OR = 7.54, 95% CI = 6.62–30.76) and POAG (P = 0.003, OR = 8.11, 95% CI = 7.13–33.15).

Conclusions

Our results demonstrated that IL-10 gene promoter polymorphisms are associated with susceptibility to PEX, PEXG and POAG in Iranian population. Considering the fact that IL-10 polymorphisms are associated with various IL-10 expressions, further research is needed to explain its involvement in these disorders and the formation of extracellular fibrillar amyloid deposits in PEX and PEXG.

Dietary Spray-Dried Porcine Plasma Prevents Cognitive Decline in Senescent Mice and Reduces Neuroinflammation and Oxidative Stress

BACKGROUND

Aging is characterized by chronic, low-grade inflammation that correlates with cognitive decline. Dietary supplementation with spray-dried porcine plasma (SDP) reduces immune activation in rodent models of inflammation and aging.

OBJECTIVE

We investigated whether the anti-inflammatory properties of SDP could ameliorate age-related cognitive deterioration and preserve brain homeostasis in an aging mouse model of senescence.

METHODS

Male senescence-accelerated prone 8 (SAMP8) mice were used. In Experiment 1, cognitive performance (n  = 10-14 mice/group) was analyzed by the novel object recognition test in 2-mo-old mice (2M group) and in mice fed a control diet or a diet supplemented with 8% SDP for 2 (4M-CTL and 4M-SDP groups) and 4 mo (6M-CTL and 6M-SDP groups). In Experiment 2, the permeability of the blood-brain barrier and junctional proteins in brain tissue was assessed, as well as synaptic density, oxidative stress markers, and inflammatory genes and proteins in mice from the 2M, 6M-CTL, and 6M-SDP groups ( n = 5-11). Statistical analyses included one-factor ANOVA followed by Fisher's posthoc test.

RESULTS

6M-SDP mice had better cognitive performance than 6M-CTL mice in both short-term (P = 0.024) and long-term (P = 0.017) memory tests. In brain tissue, 6M-SDP mice showed reduced brain capillary permeability (P = 0.034) and increased ZO1 and E-cadherin expression (both P <0.04) compared with 6M-CTL mice. SDP also prevented the NFκB activation observed in 6M-CTL mice (P = 0.002) and reduced Il6 expression and hydrogen peroxide concentration (both P <0.03) observed in 6M-CTL mice. SDP also increased the concentration of IL10 (P = 0.027), an anti-inflammatory cytokine correlated with memory preservation.

CONCLUSIONS

In senescent SAMP8 mice, dietary supplementation with SDP attenuated cognitive decline and prevented changes in brain markers of neuroinflammation and oxidative stress.

Diphtheria toxoid nanoparticles improve learning and memory impairment in animal model of Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disorder involving memory. The present study aimed at evaluating the effects of encapsulated diphtheria toxoid (DT) on behavioral learning impairment, and XBP1 mRNA splicing in AD.

METHODS

A DT-loaded nanoparticle (NP) carrier was prepared using the ionic gelation method. Sixty-three rats were divided into nine groups: (1) healthy, (2-4) sham, and (5-9) AD models: (5) AD was induced by intracerebroventricular injection of amyloid beta (Aβ) 1-42. (6) The rats received a subcutaneous diphtheria vaccine only 28 days before Aβ injection. (7) The rats received an intranasal diphtheria vaccine, in group 8, induced by administering empty chitosan NPs. 9) it was induced by administering chitosan NPs carrying DT. Morris water maze (MWM) test was used to examine the animals' learning and memory. Also, X-box binding protein 1 (XBP-1) mRNA gene splicing was studied in the hippocampus by reverse-transcription polymerase chain reaction (RT-PCR).

RESULTS

For the first time, chitosan NPs were prepared with an average diameter size of 40 nm and the effectiveness of approximately 70% during DT encapsulation. In comparison with the healthy group, the AD models exhibited significant impairment of learning and memory (P < 0.05), while DT-administrated animals showed significant improvements in learning and memory impairment (P < 0.05). XBP-1 mRNA gene splicing was only detected in an untreated AD group, while encapsulated DT completely inhibited splicing.

CONCLUSION

The therapeutic effects of DT chitosan NPs against learning and memory impairment were observed in this study, and XBP1 mRNA splicing was reported in the animal models.

Interleukin-10 and transforming growth factor-β1 facilitate long-term potentiation in CA1 region of hippocampus

It has been shown that pro-inflammatory cytokines preferentially attenuate long-term potentiation (LTP), at the same time the effect of anti-inflammatory cytokines on synaptic plasticity has not been fully studied yet. Here we studied the effect of two anti-inflammatory cytokines - interleukin-10 (IL-10) and transforming growth factor-β1 (TGF-β1) on long-term potentiation. It was found that exogenously added IL-10 as well as TGF-β1 were able to effectively facilitate LTP evoked with ether high frequency or theta burst stimulation protocols in CA1 area of hippocampus. Effectiveness of IL-10 and TGF-β1 on LTP varied depending on the concentration of used cytokine and type of tetanic stimulation protocol used for LTP induction. Overall the positive effect of studied cytokines on LTP was associated with their ability to increase basal synaptic strength at Schaffer collateral - CA1 synapse. At the same time IL-10 and TGF-β1 did not have any effect on short-term plasticity. Our results provide new evidence upon the modulatory effects that anti-inflammatory cytokines exert on synaptic plasticity further highlighting their potency as modulators of neuronal function.

Interleukin-10 Facilitates Glutamatergic Synaptic Transmission and Homeostatic Plasticity in Cultured Hippocampal Neurons

Anti-inflammatory cytokines are known to exert neuroprotective action ameliorating aberrant neuronal network activity associated with inflammatory responses. Yet, it is still not fully understood if anti-inflammatory cytokines play a significant role in the regulation of synaptic activity under normal conditions. Thus, the aim of our study was to investigate the effect of Interleukin-10 (IL-10) on neuronal synaptic transmission and plasticity. For this we tested the effect of IL-10 on miniature excitatory postsynaptic currents (mEPSC) and intracellular Ca²⁺ responses using whole-cell patch clamp and fluorescence microscopy in 13–15 DIV primary hippocampal neuroglial culture. We found that IL-10 significantly potentiated basal glutamatergic excitatory synaptic transmission within 15 min after application. Obtained results revealed a presynaptic nature of the effect, as IL-10 in a dose-dependent manner significantly increased the frequency but not the amplitude of mEPSC. Further, we tested the effect of IL-10 on mEPSC in a model of homeostatic synaptic plasticity (HSP) induced by treatment of primary hippocampal culture with 1 µM of tetrodotoxin (TTX) for a 24 h. It was found that 15 min application of IL-10 at established HSP resulted in enhanced mEPSC frequency, thus partially compensating for a decrease in the mEPSC frequency associated with TTX-induced HSP. Next, we studied if IL-10 can influence induction of HSP. We found that co-incubation of IL-10 with 1 µM of TTX for 24 h induced synaptic scaling, significantly increasing the amplitude of mEPSC and Ca²⁺ responses to application of the AMPA agonist, 5-Fluorowillardiine, thus facilitating a compensatory postsynaptic mechanism at HSP condition. Our results indicate that IL-10 potentiates synaptic activity in a dose- and time-dependent manner exerting both presynaptic (short-term exposure) and postsynaptic (long-term exposure) action. Obtained results demonstrate involvement of IL-10 in the regulation of basal glutamatergic synaptic transmission and plasticity at normal conditions.

The Post-amyloid Era in Alzheimer's Disease: Trust Your Gut Feeling

The amyloid hypothesis, the assumption that beta-amyloid toxicity is the primary cause of neuronal and synaptic loss, has been the mainstream research concept in Alzheimer's disease for the past two decades. Currently, this model is quietly being replaced by a more holistic, “systemic disease” paradigm which, like the aging process, affects multiple body tissues and organs, including the gut microbiota. It is well-established that inflammation is a hallmark of cellular senescence; however, the infection-senescence link has been less explored. Microbiota-induced senescence is a gradually emerging concept promoted by the discovery of pathogens and their products in Alzheimer's disease brains associated with senescent neurons, glia, and endothelial cells. Infectious agents have previously been associated with Alzheimer's disease, but the cause vs. effect issue could not be resolved. A recent study may have settled this debate as it shows that gingipain, a Porphyromonas gingivalis toxin, can be detected not only in Alzheimer's disease but also in the brains of older individuals deceased prior to developing the illness. In this review, we take the position that gut and other microbes from the body periphery reach the brain by triggering intestinal and blood-brain barrier senescence and disruption. We also surmise that novel Alzheimer's disease findings, including neuronal somatic mosaicism, iron dyshomeostasis, aggressive glial phenotypes, and loss of aerobic glycolysis, can be explained by the infection-senescence model. In addition, we discuss potential cellular senescence targets and therapeutic strategies, including iron chelators, inflammasome inhibitors, senolytic antibiotics, mitophagy inducers, and epigenetic metabolic reprograming.

Carnosine Prevents Aβ-Induced Oxidative Stress and Inflammation in Microglial Cells: A Key Role of TGF-β1

Carnosine (β-alanyl-L-histidine), a dipeptide, is an endogenous antioxidant widely distributed in excitable tissues like muscles and the brain. Carnosine is involved in cellular defense mechanisms against oxidative stress, including the inhibition of amyloid-beta (Aβ) aggregation and the scavenging of reactive species. Microglia play a central role in the pathogenesis of Alzheimer's disease, promoting neuroinflammation through the secretion of inflammatory mediators and free radicals. However, the effects of carnosine on microglial cells and neuroinflammation are not well understood. In the present work, carnosine was tested for its ability to protect BV-2 microglial cells against oligomeric Aβ1-42-induced oxidative stress and inflammation. Carnosine prevented cell death in BV-2 cells challenged with Aβ oligomers through multiple mechanisms. Specifically, carnosine lowered the oxidative stress by decreasing NO and O₂-• intracellular levels as well as the expression of iNOS and Nox enzymes. Carnosine also decreased the secretion of pro-inflammatory cytokines such as IL-1β, simultaneously rescuing IL-10 levels and increasing the expression and the release of TGF-β1. Carnosine also prevented Aβ-induced neurodegeneration in mixed neuronal cultures challenged with Aβ oligomers, and these neuroprotective effects were completely abolished by SB431542, a selective inhibitor of the type-1 TGF-β receptor. Our data suggest a multimodal mechanism of action of carnosine underlying its protective effects on microglial cells against Aβ toxicity with a key role of TGF-β1 in mediating these protective effects.

N-Palmitoylethanolamine-oxazoline (PEA-OXA): A new therapeutic strategy to reduce neuroinflammation, oxidative stress associated to vascular dementia in an experimental model of repeated bilateral common carotid arteries occlusion

AIM

Recent studies revealed that pharmacological modulation of NAE-hydrolyzing acid amidase (NAAA) can be achieved with PEA oxazoline (PEA-OXA). Hence, the aim of the present work was to thoroughly evaluate the anti-inflammatory and neuroprotective effects of PEA-OXA in an experimental model of vascular dementia (VaD) induced by bilateral carotid arteries occlusion. At 24 h after VaD induction, animals were orally administered with 10 mg/kg of PEA-OXA daily for 15 days.

RESULTS

Brain tissues were handled for histological, immunohistochemical, western blot, and immunofluorescence analysis. PEA-OXA treatment evidently reduced the histological alterations and neuronal death induced by VaD and additionally improved behavioral deficits. Further, PEA-OXA decreased GFAP and Iba-1, markers of astrocytes, and microglia activation, as well as increased MAP-2, a marker of neuron development. Moreover, PEA-OXA reduced oxidative stress, modulated Nrf2-mediated antioxidant response, and inhibited the apoptotic process.

INNOVATION

Some drugs may demonstrate their healing potential by regulating neuroinflammation, rather than by their habitually attributed actions only. Palmitoylethanolamide (PEA) is a prototype ALIAmide, well-known for its analgesic, anti-inflammatory, and neuroprotective properties. The inhibition of PEA degradation by targeting NAAA, its catabolic enzyme, is a different approach for treating neuroinflammation. This research offers new insight into the mechanism of PEA-OXA-induced neuroprotection.

CONCLUSION

Thus, the modulation of intracellular NAAA by PEA-OXA could offer a novel means of controlling neuroinflammatory conditions associated with VaD.

The Critical Role of IL-10 in the Antineuroinflammatory and Antioxidative Effects of Rheum tanguticum on Activated Microglia

Rheum tanguticum Maxim. ex Balf. (Rt), a traditional Tibetan medicine, is known to exert various bioactivities, including anti-inflammatory and antioxidative activities. The present study was conducted to investigate anti-inflammatory and antioxidative effects of Rt on activated microglia. Rt (10 μg/ml) significantly inhibited the mean protein level of interleukin-1β (IL-1β) in the organotypic hippocampal slice cultures following treatment with chromogranin A (CGA, 10 nM) and pancreastatin (10 nM), endogenous microglial activators present in senile plaques. Rt also significantly inhibited the expression and production of inflammatory and oxidative molecules, including IL-1β, tumor necrosis factor-α, and nitric oxide, by cultured microglia after treatment with CGA. These effects of Rt are considered to be mediated by the secretion of interleukin-10 (IL-10) from microglia, because neutralizing antibodies against IL-10 significantly canceled these effects. To explore the causative components of Rt responsible for inducing the secretion of IL-10, the effects of seven components of Rt on the IL-10 expression in microglia were examined. Among them, aloe-emodin (10 μM) and (+)-catechin (30 μM) were able to induce the secretion of IL-10 from cultured microglia. Therefore, aloe-emodin and (+)-catechin are deemed responsible for the antineuroinflammatory and antioxidative effects of Rt through the secretion of IL-10 from microglia. Accordingly, Rt is considered potentially useful for the treatment of AD.