The immune-modulatory role of apolipoprotein E with emphasis on multiple sclerosis and experimental autoimmune encephalomyelitis. Clin Dev Immunol. 2010;2010:186813. [PMID: 20613949 PMCID: PMC2896842 DOI: 10.1155/2010/186813]

Single-cell profiling indicates a high similarity between immune cells in the cerebrospinal fluid and in meningeal ectopic lymphoid tissue in experimental autoimmune encephalomyelitis

Background and objectives

B cell depleting anti-CD20 monoclonal antibodies (aCD20 mAbs) are highly effective in treatment of multiple sclerosis (MS) but fail to halt the formation of meningeal ectopic lymphoid tissue (mELT) in the murine model experimental autoimmune encephalomyelitis (EAE). While mELT can be examined in EAE, it is not accessible in vivo in MS patients. Our key objectives were to compare the immune cells in cerebrospinal fluid (CSF), which is accessible in patients, with those in mELT, and to study the effects of aCD20 mAbs on CSF and mELT in EAE.

Methods

Applying single cell RNA sequencing, we compared gene expression profiles in immune cells from (1) CSF with mELT and (2) aCD20 mAbs treated with control treated mice in a spontaneous 2D2xTh EAE model.

Results

The immune cell composition in CSF and mELT was very similar. Gene expression profiles and pathway enrichment analysis revealed no striking differences between the two compartments. aCD20 mAbs led not only to a virtually complete depletion of B cells in the CSF but also to a reduction of naïve CD4+ T cells and marked increase of macrophages. No remarkable differences in regulated genes or pathways were observed.

Discussion

Our results suggest that immune cells in the CSF may serve as a surrogate for mELT in EAE. Future studies are required to confirm this in MS patients. The observed increase of macrophages in B cell depleted CSF is a novel finding and requires verification in CSF of aCD20 mAbs treated MS patients. Due to unresolved technical challenges, we were unable to study the effects of aCD20 mAbs on mELT. This should be addressed in future studies.

Elevated pretreatment serum apolipoprotein E level associated with poor prognosis of patients with COVID-19 during the omicron BA.5 and BF.7 wave

The SARS-CoV-2 virus is responsible for the human disease known as COVID-19. This virus is capable of generating a spectrum of infections ranging from moderate to severe. Serum apolipoprotein E (ApoE) inhibits inflammation by preserving immune regulatory function. Nonetheless, the relationship between serum ApoE and clinical prognosis in omicron remains elusive. A cohort of 231 patients was observed for 65 days, with death as the primary outcome. Based on their ApoE levels, the patients were categorized into patients with elevated ApoE levels and those with lower ApoE levels. To do statistical comparisons, the log-rank test was utilized, and the Kaplan-Meier method was utilized to estimate survival rates. Cox hazard models, both univariate and multivariate, were employed to examine the prognostic relevance. According to our research, omicron had significantly greater ApoE levels. In mild-to-moderate and severe cases, the study identified a statistically significant variation in ApoE levels. Additionally, there was a drop in overall survival that is statistically significant (OS, p < 0.0001) for patients with greater ApoE levels. Multiple Cox proportional hazards regression analysis indicates that an elevated ApoE level was determined to be an adverse and independent prognostic factor of OS in patients with omicron. Taken together, our study found that the level of serum ApoE at the time of initial diagnosis was substantially connected to the severity and prognosis of omicron. Consequently, we propose that ApoE might be a poor prognostic factor in individuals afflicted with the omicron variant.

Epigenetic dysregulation in Alzheimer's disease peripheral immunity

The peripheral immune system in Alzheimer's disease (AD) has not been thoroughly studied with modern sequencing methods. To investigate epigenetic and transcriptional alterations to the AD peripheral immune system, we used single-cell sequencing strategies, including assay for transposase-accessible chromatin and RNA sequencing. We reveal a striking amount of open chromatin in peripheral immune cells in AD. In CD8 T cells, we uncover a cis-regulatory DNA element co-accessible with the CXC motif chemokine receptor 3 gene promoter. In monocytes, we identify a novel AD-specific RELA transcription factor binding site adjacent to an open chromatin region in the nuclear factor kappa B subunit 2 gene. We also demonstrate apolipoprotein E genotype-dependent epigenetic changes in monocytes. Surprisingly, we also identify differentially accessible chromatin regions in genes associated with sporadic AD risk. Our findings provide novel insights into the complex relationship between epigenetics and genetic risk factors in AD peripheral immunity.

Identification and prognostic analysis of candidate biomarkers for lung metastasis in colorectal cancer

Colorectal cancer (CRC) is one of the most prevalent types of malignant tumors. It's vital to explore new biomarkers and potential therapeutic targets in CRC lung metastasis through adopting integrated bioinformatics tools. Multiple cohort datasets and databases were integrated to clarify and verify potential key candidate biomarkers and signal transduction pathways in CRC lung metastasis. DAVID, STRING, UALCAN, GEPIA, TIMER, cBioPortal, THE HUMAN PROTEIN ATLAS, GSEA 4.3.2, FUNRICH 3.1.3, and R 4.2.3 were utilized in this study. The enriched biological processes and pathways modulated by the differentially expressed genes (DEGs) were determined with Gene Ontology, Kyoto Encyclopedia of Genes and Genomes. The search tool Retrieval of Interacting Genes and Cytoscape were used to construct a protein-protein interaction network among DEGs. Four hundred fifty-nine colorectal primary cancer and lung metastatic gene expression profiles were screened from 3 gene expression profiles (GSE41258, GSE68468, and GSE41568). Forty-one upregulated genes and 8 downregulated genes were identified from these 3 gene expression profiles and verified by the transcriptional levels of hub genes in other GEO datasets and The Cancer Genome Atlas database. Two pathways (immune responses and chemokine receptors bind chemokines), 13 key DEGs, 6 hub genes (MMP3, SFTPD, ABCA3, CLU, APOE, and SPP1), and 2 biomarkers (APOE, SPP1) with significantly prognostic values were screened. Forty-nine DEGs were identified as potential candidate diagnostic biomarkers for patients with CRC lung metastasis in present study. Enrichment analysis indicated that immune responses and chemokine receptors bind chemokines may play a leading role in lung metastasis of CRC, and further studies are needed to validate these findings.

Genetic inhibition of CARD9 accelerates the development of atherosclerosis in mice through CD36 dependent-defective autophagy

Caspase recruitment-domain containing protein 9 (CARD9) is a key signaling pathway in macrophages but its role in atherosclerosis is still poorly understood. Global deletion of Card9 in Apoe-/- mice as well as hematopoietic deletion in Ldlr-/- mice increases atherosclerosis. The acceleration of atherosclerosis is also observed in Apoe-/-Rag2-/-Card9-/- mice, ruling out a role for the adaptive immune system in the vascular phenotype of Card9 deficient mice. Card9 deficiency alters macrophage phenotype through CD36 overexpression with increased IL-1β production, increased lipid uptake, higher cell death susceptibility and defective autophagy. Rapamycin or metformin, two autophagy inducers, abolish intracellular lipid overload, restore macrophage survival and autophagy flux in vitro and finally abolish the pro-atherogenic effects of Card9 deficiency in vivo. Transcriptomic analysis of human CARD9-deficient monocytes confirms the pathogenic signature identified in murine models. In summary, CARD9 is a key protective pathway in atherosclerosis, modulating macrophage CD36-dependent inflammatory responses, lipid uptake and autophagy.

Programmed ageing: decline of stem cell renewal, immunosenescence, and Alzheimer's disease

The characteristic maximum lifespan varies enormously across animal species from a few hours to hundreds of years. This argues that maximum lifespan, and the ageing process that itself dictates lifespan, are to a large extent genetically determined. Although controversial, this is supported by firm evidence that semelparous species display evolutionarily programmed ageing in response to reproductive and environmental cues. Parabiosis experiments reveal that ageing is orchestrated systemically through the circulation, accompanied by programmed changes in hormone levels across a lifetime. This implies that, like the circadian and circannual clocks, there is a master 'clock of age' (circavital clock) located in the limbic brain of mammals that modulates systemic changes in growth factor and hormone secretion over the lifespan, as well as systemic alterations in gene expression as revealed by genomic methylation analysis. Studies on accelerated ageing in mice, as well as human longevity genes, converge on evolutionarily conserved fibroblast growth factors (FGFs) and their receptors, including KLOTHO, as well as insulin-like growth factors (IGFs) and steroid hormones, as key players mediating the systemic effects of ageing. Age-related changes in these and multiple other factors are inferred to cause a progressive decline in tissue maintenance through failure of stem cell replenishment. This most severely affects the immune system, which requires constant renewal from bone marrow stem cells. Age-related immune decline increases risk of infection whereas lifespan can be extended in germfree animals. This and other evidence suggests that infection is the major cause of death in higher organisms. Immune decline is also associated with age-related diseases. Taking the example of Alzheimer's disease (AD), we assess the evidence that AD is caused by immunosenescence and infection. The signature protein of AD brain, Aβ, is now known to be an antimicrobial peptide, and Aβ deposits in AD brain may be a response to infection rather than a cause of disease. Because some cognitively normal elderly individuals show extensive neuropathology, we argue that the location of the pathology is crucial - specifically, lesions to limbic brain are likely to accentuate immunosenescence, and could thus underlie a vicious cycle of accelerated immune decline and microbial proliferation that culminates in AD. This general model may extend to other age-related diseases, and we propose a general paradigm of organismal senescence in which declining stem cell proliferation leads to programmed immunosenescence and mortality.

Modulation of long noncoding RNA (lncRNA) and messenger RNA (mRNA) expression in the liver of Beagle dogs by Toxocara canis infection

BACKGROUND

Long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) play crucial roles in regulating various physiological and pathological processes. However, the role of lncRNAs and mRNAs in mediating the liver response during Toxocara canis infection remains incompletely understood.

METHODS

In the present study, the expression profile of lncRNAs and mRNAs was investigated in the liver of Beagle dogs infected by T. canis using high-throughput RNA sequencing.

RESULTS

Compared with the control groups, 876 differentially expressed (DE) lncRNAs and 288 DEmRNAs were identified at 12 h post-infection (hpi), 906 DElncRNAs and 261 DEmRNAs were identified at 24 hpi, and 876 DElncRNAs and 302 DEmRNAs were identified at 36 days post-infection (dpi). A total of 16 DEmRNAs (e.g. dpp4, crp and gnas) were commonly identified at the three infection stages. Enrichment and co-localization analyses identified several pathways involved in immune and inflammatory responses during T. canis infection. Some novel DElncRNAs, such as LNC_015756, LNC_011050 and LNC_011052, were also associated with immune and inflammatory responses. Also, LNC_005105 and LNC_005401 were associated with the secretion of anti-inflammatory cytokines, which may play a role in the healing of liver pathology at the late stage of infection.

CONCLUSIONS

Our data provided new insight into the regulatory roles of lncRNAs and mRNAs in the pathogenesis of T. canis and improved our understanding of the contribution of lncRNAs and mRNAs to the immune and inflammatory response of the liver during T. canis infection.

From degenerative disease to malignant tumors: Insight to the function of ApoE

Apolipoprotein E (ApoE) is a multifunctional protein involved in lipid transport and lipoprotein metabolism, mediating lipid distribution/redistribution in tissues and cells. It can also regulate inflammation and immune function, maintain cytoskeleton stability, and improve neural tissue Function. Due to genetic polymorphisms of ApoE (ε2, ε3, and ε4), its three common structural isoforms (ApoE2, ApoE3, ApoE4) are also associated with the risk of many diseases, especially degenerative diseases, such as vascular degenerative diseases including atherosclerosis (AS), coronary heart disease (CHD), and neurodegenerative disease like Alzheimer's disease (AD). The frequency of the ε4 allele and APOE variants were significantly higher than that of the ε2 and ε3 alleles in the patients with CHD or AD. In recent years, ApoE has frequently appeared in tumor research and become a tumor biomarker gradually. It has been found that ApoE is highly expressed in most solid tumor tissues, such as glioblastoma, gastric cancer, pancreatic ductal cell carcinoma, etc. Studies illustrated that ApoE could regulate the polarization changes of macrophages, participate in the construction of tumor immune microenvironment, regulate tumor inflammation and immune response and play a role in tumor progression, invasion, and metastasis. Of course, many functions of ApoE and its relationship with diseases are still under research. By reviewing the structure and function of ApoE from degeneration diseases to tumor neoplasms, we hope to better understand such a biomarker and further explore the value of ApoE in later studies.

Insight into Early Diagnosis of Multiple Sclerosis by Targeting Prognostic Biomarkers

Multiple sclerosis (MS) is a central nervous system (CNS) immune-mediated disease that mainly strikes young adults and leaves them disabled. MS is an autoimmune illness that causes the immune system to attack the brain and spinal cord. The myelin sheaths, which insulate the nerve fibers, are harmed by our own immune cells, and this interferes with brain signal transmission. Numbness, tingling, mood swings, memory problems, exhaustion, agony, vision problems, and/or paralysis are just a few of the symptoms. Despite technological advancements and significant research efforts in recent years, diagnosing MS can still be difficult. Each patient's MS is distinct due to a heterogeneous and complex pathophysiology with diverse types of disease courses. There is a pressing need to identify markers that will allow for more rapid and accurate diagnosis and prognosis assessments to choose the best course of treatment for each MS patient. The cerebrospinal fluid (CSF) is an excellent source of particular indicators associated with MS pathology. CSF contains molecules that represent pathological processes such as inflammation, cellular damage, and loss of blood-brain barrier integrity. Oligoclonal bands, neurofilaments, MS-specific miRNA, lncRNA, IgG-index, and anti-aquaporin 4 antibodies are all clinically utilised indicators for CSF in MS diagnosis. In recent years, a slew of new possible biomarkers have been presented. In this review, we look at what we know about CSF molecular markers and how they can aid in the diagnosis and differentiation of different MS forms and treatment options, and monitoring and predicting disease progression, therapy response, and consequences during such opportunistic infections.

In silico study of tacrine and acetylcholine binding profile with human acetylcholinesterase: docking and electronic structure

Alzheimer disease (AD) is a neurodegenerative process, one of the most common and incident dementia in the population over 60 years. AD manifests the presence of complex biochemical processes involved in neuronal degeneration, such as the formation of senile plaques containing amyloid-β peptides, the development of intracellular neurofibrillary tangles, and the suppression of the acetylcholine neurotransmitter. In this way, we performed a set of theoretical tests of tacrine ligand and acetylcholine neurotransmitter against the human acetylcholinesterase enzyme. Molecular docking was used to understand the most important interactions of these molecules with the enzyme. Computational chemistry calculation was carried out using MP2, DFT, and semi-empirical methods, starting from molecular docking structures. We have also performed studies regarding the non-covalent interactions, electron localization function, molecular electrostatic potential and explicit water molecule influence. For Trp86 residue, we show two main interactions in accordance to the results of the literature for TcAChE. First, intermolecular interactions of the cation-π and sigma-π type were found. Second, close stacking interactions were stablished between THA+ and Trp86 residue on one side and with Tyr337 residue on the other side.

New Insights into the Molecular Interplay between Human Herpesviruses and Alzheimer’s Disease—A Narrative Review

Human herpesviruses (HHVs) have been implicated as possible risk factors in Alzheimer’s disease (AD) pathogenesis. Persistent lifelong HHVs infections may directly or indirectly contribute to the generation of AD hallmarks: amyloid beta (Aβ) plaques, neurofibrillary tangles composed of hyperphosphorylated tau proteins, and synaptic loss. The present review focuses on summarizing current knowledge on the molecular mechanistic links between HHVs and AD that include processes involved in Aβ accumulation, tau protein hyperphosphorylation, autophagy, oxidative stress, and neuroinflammation. A PubMed search was performed to collect all the available research data regarding the above mentioned mechanistic links between HHVs and AD pathology. The vast majority of research articles referred to the different pathways exploited by Herpes Simplex Virus 1 that could lead to AD pathology, while a few studies highlighted the emerging role of HHV 6, cytomegalovirus, and Epstein–Barr Virus. The elucidation of such potential links may guide the development of novel diagnostics and therapeutics to counter this devastating neurological disorder that until now remains incurable.

Association of APOE Serum Levels and APOE ε2, ε3, and ε4 Alleles with Optic Neuritis

Optical neuritis (ON), otherwise known as optical nerve damage, is a term used to describe various environmental and body conditions that lead to optic nerve dysfunction. Neurologists are well aware of conditions that cause optic neuropathy, such as trauma, infections, malnutrition, and various toxins. As optic neuritis is a multifactorial demyelinating or infectious process, genetic predisposition may also influence the progression of optic neuritis. This study aimed to evaluate the association of ON (with and without multiple sclerosis) with APOE alleles and APOE serum levels. We found that the APOE ε3/ε3 genotype was statistically less common in the ON group of males than in the control group (p = 0.045). Moreover, the APOE ε3/ε3 genotype had a 3.7-fold increase in the odds of ON development in males (OR = 3.698; CI: 1.503–9.095; p = 0.004). In contrast, the APOE ε3/ε4 genotype had a 4.1-fold decrease in the odds of ON development in males (OR = 0.242; CI: 0.083–0.704; p = 0.009). APOE serum levels were statistically significantly higher in the ON group than in the control group (p = 0.042). The APOE ε3/ε3 genotype may increase males’ risk of developing ON, while the ε3/ε4 genotype may reduce males’ risk of developing ON.

A tale of two systems: Lessons learned from female mid-life aging with implications for Alzheimer's prevention & treatment

Neurological aging is frequently viewed as a linear process of decline, whereas in reality, it is a dynamic non-linear process. The dynamic nature of neurological aging is exemplified during midlife in the female brain. To investigate fundamental mechanisms of midlife aging that underlie risk for development of Alzheimer's disease (AD) in late life, we investigated the brain at greatest risk for the disease, the aging female brain. Outcomes of our research indicate that mid-life aging in the female is characterized by the emergence of three phases: early chronological (pre-menopause), endocrinological (peri-menopause) and late chronological (post-menopause) aging. The endocrinological aging program is sandwiched between early and late chronological aging. Throughout the three stages of midlife aging, two systems of biology, metabolic and immune, are tightly integrated through a network of signaling cascades. The network of signaling between these two systems of biology underlie an orchestrated sequence of adaptative starvation responses that shift the brain from near exclusive dependence on a single fuel, glucose, to utilization of an auxiliary fuel derived from lipids, ketone bodies. The dismantling of the estrogen control of glucose metabolism during mid-life aging is a critical contributor to the shift in fuel systems and emergence of dynamic neuroimmune phenotype. The shift in fuel reliance, puts the largest reservoir of local fatty acids, white matter, at risk for catabolism as a source of lipids to generate ketone bodies through astrocytic beta oxidation. APOE4 genotype accelerates the tipping point for emergence of the bioenergetic crisis. While outcomes derived from research conducted in the female brain are not directly translatable to the male brain, the questions addressed in a female centric program of research are directly applicable to investigation of the male brain. Like females, males with AD exhibit deficits in the bioenergetic system of the brain, activation of the immune system and hallmark Alzheimer's pathologies. The drivers and trajectory of mechanisms underlying neurodegeneration in the male brain will undoubtedly share common aspects with the female in addition to factors unique to the male. Preclinical and clinical evidence indicate that midlife endocrine aging can also be a transitional bridge to autoimmune disorders. Collectively, the data indicate that endocrinological aging is a critical period "tipping point" in midlife which can initiate emergence of the prodromal stage of late-onset-Alzheimer's disease. Interventions that target both immune and metabolic shifts that occur during midlife aging have the potential to alter the trajectory of Alzheimer's risk in late life. Further, to achieve precision medicine for AD, chromosomal sex is a critical variable to consider along with APOE genotype, other genetic risk factors and stage of disease.

ApoE4-positive multiple sclerosis patients are more likely to have cognitive impairment: a cross-sectional study

BACKGROUND

Multiple sclerosis (MS) presents with a wide variety of symptoms, including cognitive dysfunction. Previous studies in terms of the possible function of the ApoE4 allele as a risk factor for cognitive dysfunction in MS patients were associated with conflicting results. The role of the ε4 isoform of apolipoprotein (ApoE4) was investigated in this study as a risk factor for cognitive dysfunction in MS patients.

METHODS

Mildly disabled relapsing-remitting MS (RRMS) patients were involved in this study. The neurocognitive assessment is conducted by the Minimal Assessment of Cognitive Function in MS (MACFIMS) battery. After determining the genotype, patients were divided into two groups of ApoE4-positive and ApoE4-negative groups, and cognitive findings were compared.

RESULTS

Seventy-one patients with a mean age of 31.43 ± 8.75 were involved in this study. Eleven out of 17 (64.70%) patients in the ApoE4-positive group had at least one impaired test, while this rate was 16 out of 54 (29.62%) in the ApoE4-negative group (p < 0.01). The rate of overall cognitive impairment (failure in ≥ 2 tests) was not statistically different between groups of the study (p = 0.75). Impairment in Paced Auditory Serial Addition Test (PASAT) task and also the mean score of Brief Visuospatial Memory Test-Revised (BVMT-R) tests were different between two groups (p = 0.01 and 0.02, respectively).

CONCLUSION

MS ApoE4-positive patients are more likely to have at least one impaired cognitive test, but there is a need for more studies with larger sample sizes and based on MS-specific cognitive tests to confirm these findings.

Genetic Regulatory Networks of Apolipoproteins and Associated Medical Risks

Apolipoproteins (APO proteins) are the lipoprotein family proteins that play key roles in transporting lipoproteins all over the body. There are nearly more than twenty members reported in the APO protein family, among which the A, B, C, E, and L play major roles in contributing genetic risks to several disorders. Among these genetic risks, the single nucleotide polymorphisms (SNPs), involving the variation of single nucleotide base pairs, and their contributing polymorphisms play crucial roles in the apolipoprotein family and its concordant disease heterogeneity that have predominantly recurred through the years. In this review, we have contributed a handful of information on such genetic polymorphisms that include APOE, ApoA1/B ratio, and A1/C3/A4/A5 gene cluster-based population genetic studies carried throughout the world, to elaborately discuss the effects of various genetic polymorphisms in imparting various medical conditions, such as obesity, cardiovascular, stroke, Alzheimer's disease, diabetes, vascular complications, and other associated risks.

Incorporation of apolipoprotein E into HBV-HCV subviral envelope particles to improve the hepatitis vaccine strategy

Hepatitis C is a major threat to public health for which an effective treatment is available, but a prophylactic vaccine is still needed to control this disease. We designed a vaccine based on chimeric HBV-HCV envelope proteins forming subviral particles (SVPs) that induce neutralizing antibodies against HCV in vitro. Here, we aimed to increase the neutralizing potential of those antibodies, by using HBV-HCV SVPs bearing apolipoprotein E (apoE). These particles were produced by cultured stable mammalian cell clones, purified and characterized. We found that apoE was able to interact with both chimeric HBV-HCV (E1-S and E2-S) proteins, and with the wild-type HBV S protein. ApoE was also detected on the surface of purified SVPs and improved the folding of HCV envelope proteins, but its presence lowered the incorporation of E2-S protein. Immunization of New Zealand rabbits resulted in similar anti-S responses for all rabbits, whereas anti-E1/-E2 antibody titers varied according to the presence or absence of apoE. Regarding the neutralizing potential of these anti-E1/-E2 antibodies, it was higher in rabbits immunized with apoE-bearing particles. In conclusion, the association of apoE with HCV envelope proteins may be a good strategy for improving HCV vaccines based on viral envelope proteins.

Bench to Bedside: Proteomic Biomarker Analysis of Cerebrospinal Fluid in Patients With Spondylomyelopathy

Establishing proteomic biomarkers is critical for characterizing disease pathophysiology, identifying genetic risk factors, and predicting clinical outcomes. However, diseases like cervical spondylomyelopathy have not been actively characterized for molecular significance, leading to questions regarding the pathology's molecular mechanisms. Namely, spondylomyelopathy is a degenerative spinal disease that leads to compression and neurologic deficits in the spinal cord. Analyzing a patient's cerebrospinal fluid (CSF) has been well-known for revealing biomarkers that are associated with diseases of the central nervous system. Therefore, in this review, we will formulate a proteomic profile of spondylomyelopathy through a molecular analysis of the CSF. The proteins found to be upregulated in the CSF include vitamin D-binding protein (VDBP), gelsolin, creatine kinase B-type (CK-BB), and angiotensinogen. Meanwhile, the proteins that were downregulated include pigment epithelium-derived factor (PEDF), prostaglandin-H2 D-isomerase (PGH2), apolipoprotein E (APOE), and clusterin. The cellular functions of these proteins are discussed, along with their relevance in manifesting spondylomyelopathy. However, further studies are warranted, as a lack of human studies is a major limiting factor. Nevertheless, based on the continued progression of the proteomic profile of spondylomyelopathy, new targets can be assessed as candidates for future therapeutic intervention.

Apolipoprotein E variants correlate with the clinical presentation of paediatric inflammatory bowel disease: A cross-sectional study

BACKGROUND

It has been suggested that apolipoprotein E (APOE) polymorphisms are associated with the risk of developing inflammatory bowel disease (IBD) and the early age of disease onset. However, there are no reports regarding the relationship with clinical characteristics and disease severity.

AIM

To summarise that APOE polymorphisms are associated with the risk of developing IBD and the early age of disease onset.

METHODS

In total, 406 patients aged 3-18 with IBD (192 had ulcerative colitis and 214 had Crohn’s disease) were genotyped using the TaqMan hydrolysis probe assay. Clinical expression was described at diagnosis and the worst flare by disease activity scales, albumin and C-reactive protein levels, localisation and behaviour (Paris classification). Systemic steroid intake with the total number of courses, immunosuppressive, biological, and surgical treatment with the time and age of the first intervention were determined. The total number of exacerbation-caused hospitalisations, the number of days spent in hospital due to exacerbation, the number of relapses, and severe relapses were also estimated.

RESULTS

Ulcerative colitis patients with the APOEε4 allele had lower C-reactive protein values at diagnosis (P = 0.0435) and the worst flare (P = 0.0013) compared to patients with the APOEε2 allele and genotype APOEε3/ε3. Crohn’s disease patients with the APOEε2 allele scored lower on the Pediatric Crohn’s Disease Activity Index at diagnosis (P = 0.0204). IBD patients with APOEε2 allele spent fewer days in the hospital due to relapse (P = 0.0440).

CONCLUSION

APOE polymorphisms are associated with the risk of developing IBD and the clinical expression of IBD. However, the clinical relevance of the differences identified is rather modest.

Role of Adaptive Immune and Impacts of Risk Factors on Adaptive Immune in Alzheimer's Disease: Are Immunotherapies Effective or Off-Target?

The pathogenesis of Alzheimer's disease (AD) is complex. Still it remains unclear, which resulted in all efforts for AD treatments with targeting the pathogenic factors unsuccessful over past decades. It has been evidenced that the innate immune is strongly implicated in the pathogenesis of AD. However, the role of adaptive immune in AD remains mostly unknown and the results obtained were controversial. In the review, we summarized recent studies and showed that the molecular and cellular alterations in AD patients and its animal models involving T cells and B cells as well as immune mediators of adaptive immune occur not only in the peripheral blood but also in the brain and the cerebrospinal fluid. The risk factors that cause AD contribute to AD progress by affecting the adaptive immune, indicating that adaptive immunity proposes a pivotal role in this disease. It may provide a possible basis for applying immunotherapy in AD and further investigates whether the immunotherapies are effective or off-target?

Comparative Proteomic Analysis of Serum from Pigs Experimentally Infected with Trichinella spiralis, Trichinella britovi, and Trichinella pseudospiralis

Although the available proteomic studies have made it possible to identify and characterize Trichinella stage-specific proteins reacting with infected host-specific antibodies, the vast majority of these studies do not provide any information about changes in the global proteomic serum profile of Trichinella-infested individuals. In view of the above, the present study aimed to examine the protein expression profile of serum obtained at 13 and 60 days postinfection (d.p.i.) from three groups of pigs experimentally infected with Trichinella spiralis, Trichinella britovi, and Trichinella pseudospiralis and from uninfected, control pigs by two-dimensional gel electrophoresis (2-DE) followed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. The comparative proteomic analysis of the T. spiralis group vs. the control group revealed 5 differently expressed spots at both 13 and 60 d.p.i. Experimental infection with T. britovi induced significant expression changes in 3 protein spots at 13 d.p.i. and in 6 protein spots at 60 d.p.i. in comparison with the control group. Paired analyses between the group infected with T. pseudospiralis and the uninfected control group revealed 6 differently changed spots at 13 d.p.i. and 2 differently changed spots at 60 d.p.i. Among these 27 spots, 15 were successfully identified. Depending on the Trichinella species triggering the infection and the time point of serum collection, they were IgM heavy-chain constant region, antithrombin III-precursor, immunoglobulin gamma-chain, clusterin, homeobox protein Mohawk, apolipoprotein E precursor, serum amyloid P-component precursor, Ig lambda chains, complement C3 isoform X1, and apolipoprotein A-I. Our results demonstrate that various Trichinella species and different phases of the invasion produce a distinct, characteristic proteomic pattern in the serum of experimentally infected pigs.

Biomarkers of Multiple Sclerosis

The search for an ideal multiple sclerosis biomarker with good diagnostic value, prognostic reference and an impact on clinical outcome has yet to be realized and is still ongoing. The aim of this review is to establish an overview of the frequent biomarkers for multiple sclerosis that exist to date. The review summarizes the results obtained from electronic databases, as well as thorough manual searches. In this review the sources and methods of biomarkers extraction are described; in addition to the description of each biomarker, determination of the prognostic, diagnostic, disease monitoring and treatment response values besides clinical impact they might possess. We divided the biomarkers into three categories according to the achievement method: laboratory markers, genetic-immunogenetic markers and imaging markers. We have found two biomarkers at the time being considered the gold standard for MS diagnostics. Unfortunately, there does not exist a single solitary marker being able to present reliable diagnostic value, prognostic value, high sensitivity and specificity as well as clinical impact. We need more studies to find the best biomarker for MS.

Protein Glycation: An Old Villain is Shedding Secrets

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The glycation of proteins is non-physiological post-translational incorporation of carbohydrates onto the free amines or guanidines of proteins and some lipids. Although the existence of glycated proteins has been known for forty years, a full understanding of their pathogenic nature has been slow in accruing. In recent years, however, glycation has gained widespread acceptance as a contributing factor in numerous metabolic, autoimmune, and neurological disorders, tying together several confounding aspects of disease etiology. From diabetes, arthritis, and lupus, to multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer’s, and Parkinson’s diseases, an emerging glycation/inflammation paradigm now offers significant new insight into a physiologically important toxicological phenomenon. It exposes novel drug targets and treatment options, and may even lay foundations for long-awaited breakthroughs.

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This ‘current frontier’ article briefly profiles current knowledge regarding the underlying causes of glycation, the structural biology implications of such modifications, and their pathological consequences. Although several emerging therapeutic strategies for addressing glycation pathologies are introduced, the primary purpose of this mini-review is to raise awareness of the challenges and opportunities inherent in this emerging new medicinal target area.

Exercise as a potential modulator of inflammation in patients with Alzheimer's disease measured in cerebrospinal fluid and plasma

BACKGROUND

Neuroinflammation is recognized as part of the pathological progression of Alzheimer's disease (AD), but the molecular mechanisms are still not entirely clear. Systemically, physical exercise has shown to have a positive modulating effect on markers of inflammation. It is not known if this general effect also takes place in the central nervous system in AD. The aim of this study was to investigate the effect of 16 weeks of moderate to high-intensity physical exercise on selected biomarkers of inflammation both systemically and in the CNS, in patients with AD.

METHODS

Plasma and cerebrospinal fluid (CSF) from 198 patients with Alzheimer's disease participating in the Preserving Cognition, Quality of Life, Physical Health and Functional Ability in Alzheimer's Disease: The Effect of Physical Exercise (ADEX) study were analyzed for concentrations of 8‑isoprostane, soluble trigger receptor expressed on myeloid cells 2 (sTREM2), and the MSD v-plex proinflammation panel 1 human containing interferon gamma (IFNγ), Interleukin-10 (IL10), IL12p70, IL13, IL1β, IL2, IL4, IL6, IL8, and tumor necrosis factor alpha (TNFα), before and after a 16-week intervention with physical exercise, and we studied whether changes were modulated by the patients' APOE genotype.

RESULTS

Most inflammatory markers remained unchanged after exercise. We found an increasing effect of 16 weeks of physical exercise on sTREM2 measured in CSF. Further, IL6 in plasma increased in the exercise group after physical exercise (mean relative change 41.03, SD 76.7), compared to controls (-0.97, SD 49.4). In a sub-analysis according to APOE genotype, we found that in ε4 carriers, exercise had a stabilizing effect on IFNγ concentration with a mean relative change of 7.84 (SD 42.6), as compared to controls (114.7 (SD 188.3), p = 0.038.

CONCLUSION

Our findings indicate an effect of physical exercise on markers of neuroinflammation in CSF measured by an increase in sTREM2 in patients with AD. Further, there may be a small inflammatory systemic effect related to physical exercise in patients with AD.

Biomarkers in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic neurodegenerative autoimmune disease with a complex clinical course characterized by inflammation, demyelination, and axonal degeneration. Diagnosis of MS most commonly includes finding lesions in at least two separate areas of the central nervous system (CNS), including the brain, spinal cord, and optic nerves. In recent years, there has been a remarkable increase in the number of available treatments for MS. An optimal treatment is usually based on a personalized approach determined by an individual patient's prognosis and treatment risks. Biomarkers that can predict disability progression, monitor ongoing disease activity, and assess treatment response are integral in making important decisions regarding MS treatment. This review describes MS biomarkers that are currently being used in clinical practice; it also reviews and consolidates published findings from clinically relevant potential MS biomarkers in recent years. The work also discusses the challenges of validating and application of biomarkers in MS clinical practice.

Serum Lipoprotein Profile Is Associated With Protective Effects of Oral Contraceptive Use on Multiple Sclerosis Severity: A Cross-Sectional Study

Background: The mechanisms underlying the influence of sex hormones in multiple sclerosis (MS) are uncertain. Sex steroids interact with cholesterol metabolism and the serum lipid profile has been associated with the severity of the disease. We hypothesized that the putative associations between lipoprotein metabolism and MS could be modulated by sex steroids exposure. The aim of this study was to investigate whether oral contraceptives (OC) use changes the lipoprotein profile associated with disability in patients with multiple sclerosis. Methods: Clinical data was collected from 133 relapsing-remitting multiple sclerosis (RRMS) women with a mean of 6.5 years of disease duration and prior to the start of disease-modifying therapies. Patients who were using OC after disease onset (DO) (OC+, n = 57) were compared to those who never used OC or discontinued its intake before DO (OC-, n = 76). In both cohorts of subjects, the associations between the apolipoprotein E (ApoE) polymorphism, and plasma lipid levels, and the annualized relapse rate (RR), the Expanded Disability Status Score (EDSS), and the Multiple Sclerosis Severity Score (MSSS) were evaluated using a hierarchic multiple regression analysis after adjustment for confounders. Results: Low density lipoprotein (LDL) levels were associated with higher EDSS (p = 0.010) and MSSS (p = 0.024) in the whole studied cohort. In E3/E3 phenotype carriers (73.7%), EDSS and MSSS were lower in OC+ in comparison with OC- subgroup of patients (p < 0.01). LDL and total cholesterol were associated with EDSS (p = 0.005 and p = 0.043, respectively), and LDL and the triglyceride/high density lipoprotein ratio with MSSS (p = 0.011 and p = 0.048, respectively) in OC+ patients. In OC- subgroup of patients, ApoE levels were associated with EDSS (p = 0.012) and MSSS (p = 0.031). No significant interactions between the lipid variables or OC use and RR were observed. Conclusions: Serum lipid profile is associated with protective effects of OC use on disability of RRMS patients. Lipoprotein metabolism may be involved in the modulatory effects of sex steroids on the severity of the disease.

The Assessment of Sexual Dysfunction in Male Patients with Multiple Sclerosis

Introduction

To investigate the effects of multiple sclerosis (MS) on male sexuality.

Methods

While 61 men with MS were included into the study group, 60 healthy men constituted the control group in the study. In MS patients, such parameters as functional status and depression levels were assessed with the Expanded Disability Status Scala (EDSS) and the Beck Depression Scale (BDS), other parameters such as pain levels, sexual function and quality of life (QoL) were evaluated with the Visual Analog Scala (VAS), the International Index of Erectile Function (IIEF) and the short form-36 (SF-36), respectively.

Results

Patients with MS were classified as 45 with EDSS <5.5 and 19 with EDSS >5.5. Mean VAS and BDI scores patients with MS were found statistically significantly higher, compared with those of the controls (p<0.05). Mean IIEF and all sub-group scores of SF-36 of patients with MS were found to be statistically significantly lower, compared with those of the control group (p<0.05). Mean EDSS in patients with MS was 2.75±2.42. While there was a positive correlation between IIEF scores of patients with MS, and mean mental and physical components of SF-36, a negative correlation was found between IIEF scores in MS patients, and age, disease duration, number of attacks, number of marital years and scores of EDSS, VAS and BDI (p<0.00). When BDI ≥17 was accepted as the threshold for depression, the depression was detected in 62.5% of patients with MS and 11.7% of the controls (p<0.001).

Conclusion

Sexual functions are affected negatively in male patients with MS and seem to be associated with increased disability, pain and accompanying depression. Therefore, male patients with MS should also be evaluated with regard to sexual function, as well as disability during their follow-ups.

Long-term effects of low-dose mouse liver irradiation involve ultrastructural and biochemical changes in hepatocytes that depend on lipid metabolism

The aim of the study was to investigate long-term effects of radiation on the (ultra)structure and function of the liver in mice. The experiments were conducted on wild-type C57BL/6J and apolipoprotein E knock-out (ApoE^-/-) male mice which received a single dose (2 or 8 Gy) of X-rays to the heart with simultaneous exposure of liver to low doses (no more than 30 and 120 mGy, respectively). Livers were collected for analysis 60 weeks after irradiation and used for morphological, ultrastructural, and biochemical studies. The results show increased damage to mitochondrial ultrastructure and lipid deposition in hepatocytes of irradiated animals as compared to non-irradiated controls. Stronger radiation-related effects were noted in ApoE^-/- mice than wild-type animals. In contrast, radiation-related changes in the activity of lysosomal hydrolases, including acid phosphatase, β-glucuronidase, N-acetyl-β-D-hexosaminidase, β-galactosidase, and α-glucosidase, were observed in wild type but not in ApoE-deficient mice, which together with ultrastructural picture suggests a higher activity of autophagy in ApoE-proficient animals. Irradiation caused a reduction of plasma markers of liver damage in wild-type mice, while an increased level of hepatic lipase was observed in plasma of ApoE-deficient mice, which collectively indicates a higher resistance of hepatocytes from ApoE-proficient animals to radiation-mediated damage. In conclusion, liver dysfunctions were observed as late effects of irradiation with an apparent association with malfunction of lipid metabolism.

Apolipoprotein E as a novel therapeutic neuroprotection target after traumatic spinal cord injury

Apolipoprotein E (apoE), a plasma lipoprotein well known for its important role in lipid and cholesterol metabolism, has also been implicated in many neurological diseases. In this study, we examined the effect of apoE on the pathophysiology of traumatic spinal cord injury (SCI). ApoE-deficient mutant (apoE^-/-) and wild-type mice received a T9 moderate contusion SCI and were evaluated using histological and behavioral analyses after injury. At 3days after injury, the permeability of spinal cord-blood-barrier, measured by extravasation of Evans blue dye, was significantly increased in apoE^-/- mice compared to wild type. The inflammation and spared white matter was also significantly increased and decreased, respectively, in apoE^-/- mice compared to the wild type ones. The apoptosis of both neurons and oligodendrocytes was also significantly increased in apoE^-/- mice. At 42days after injury, the inflammation was still robust in the injured spinal cord in apoE^-/- but not wild type mice. CD45+ leukocytes from peripheral blood persisted in the injured spinal cord of apoE^-/- mice. The spared white matter was significantly decreased in apoE^-/- mice compared to wild type ones. Locomotor function was significantly decreased in apoE^-/- mice compared to wild type ones from week 1 to week 8 after contusion. Treatment of exogenous apoE mimetic peptides partially restored the permeability of spinal cord-blood-barrier in apoE^-/- mice after SCI. Importantly, the exogenous apoE peptides decreased inflammation, increased spared white matter and promoted locomotor recovery in apoE^-/- mice after SCI. Our results indicate that endogenous apoE plays important roles in maintaining the spinal cord-blood-barrier and decreasing inflammation and spinal cord tissue loss after SCI, suggesting its important neuroprotective function after SCI. Our results further suggest that exogenous apoE mimetic peptides could be a novel and promising neuroprotective reagent for SCI.

Overlooked Mechanisms in Type 1 Diabetes Etiology: How Unique Costimulatory Molecules Contribute to Diabetogenesis

Type 1 Diabetes (T1D) develops when immune cells invade the pancreatic islets resulting in loss of insulin production in beta cells. T cells have been proven to be central players in that process. What is surprising, however, is that classic mechanisms of tolerance cannot explain diabetogenesis; alternate mechanisms must now be considered. T cell receptor (TCR) revision is the process whereby T cells in the periphery alter TCR expression, outside the safety-net of thymic selection pressures. This process results in an expanded T cell repertoire, capable of responding to a universe of pathogens, but limitations are that increased risk for autoimmune disease development occurs. Classic T cell costimulators including the CD28 family have long been thought to be the major drivers for full T cell activation. In actuality, CD28 and its family member counterparts, ICOS and CTLA-4, all drive regulatory responses. Inflammation is driven by CD40, not CD28. CD40 as a costimulus has been largely overlooked. When naïve T cells interact with antigen presenting cell CD154, the major ligand for CD40, is induced. This creates a milieu for T cell (CD40)-T cell (CD154) interaction, leading to inflammation. Finally, defined pathogenic effector cells including TH40 (CD4⁺CD40⁺) cells can express FOXP3 but are not Tregs. The cells loose FOXP3 to become pathogenic effector cells. Each of these mechanisms creates novel options to better understand diabetogenesis and create new therapeutic targets for T1D.

Apolipoprotein E Gene Polymorphisms in Saudi Patients with Systemic Lupus Erythematosus

Apolipoprotein E (APOE) is a glycosylated protein with multiple biological properties. APOE gene polymorphism plays a central role in lipid metabolism and has recently been suggested to regulate inflammation. Our objective is to evaluate whether APOE polymorphism affects susceptibility to SLE. APOE genotyping was performed using ApoE StripAssay™ kit. Results indicated significantly higher frequencies of allele ε4 and genotype ε3/ε4 and lower frequencies of allele ε3 and genotype ε3/ε3 in SLE patients than controls. APOE ε2 allele was found in three patients, whereas it was absent in controls. The frequencies of allele ε4 and genotype ε3/ε4 were significantly higher in SLE patients with renal involvement and those of alleles ε2, ε4 and genotypes ε2/ε3, ε3/ε4 were higher in patients with neuropsychiatric symptoms. It is concluded that APOE allele ε4 is associated with susceptibility risk/clinical manifestations of SLE and ε2 may increase its severity while ε3 is protective for SLE in Saudis.

Comparative Proteomic Analysis of Two Uveitis Models in Lewis Rats

PURPOSE

Inflammation generates changes in the protein constituents of the aqueous humor. Proteins that change in multiple models of uveitis may be good biomarkers of disease or targets for therapeutic intervention. The present study was conducted to identify differentially-expressed proteins in the inflamed aqueous humor.

METHODS

Two models of uveitis were induced in Lewis rats: experimental autoimmune uveitis (EAU) and primed mycobacterial uveitis (PMU). Differential gel electrophoresis was used to compare naïve and inflamed aqueous humor. Differentially-expressed proteins were separated by using 2-D gel electrophoresis and excised for identification with matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF). Expression of select proteins was verified by Western blot analysis in both the aqueous and vitreous.

RESULTS

The inflamed aqueous from both models demonstrated an increase in total protein concentration when compared to naïve aqueous. Calprotectin, a heterodimer of S100A8 and S100A9, was increased in the aqueous in both PMU and EAU. In the vitreous, S100A8 and S100A9 were preferentially elevated in PMU. Apolipoprotein E was elevated in the aqueous of both uveitis models but was preferentially elevated in EAU. Beta-B2-crystallin levels decreased in the aqueous and vitreous of EAU but not PMU.

CONCLUSIONS

The proinflammatory molecules S100A8 and S100A9 were elevated in both models of uveitis but may play a more significant role in PMU than EAU. The neuroprotective protein β-B2-crystallin was found to decline in EAU. Therapies to modulate these proteins in vivo may be good targets in the treatment of ocular inflammation.

Investigation of sex-specific effects of apolipoprotein E on severity of EAE and MS

Background

Despite pleiotropic immunomodulatory effects of apolipoprotein E (apoE) in vitro, its effects on the clinical course of experimental autoimmune encephalomyelitis (EAE) and multiple sclerosis (MS) are still controversial. As sex hormones modify immunomodulatory apoE functions, they may explain contentious findings. This study aimed to investigate sex-specific effects of apoE on disease course of EAE and MS.

Methods

MOG_35-55 induced EAE in female and male apoE-deficient mice was assessed clinically and histopathologically. apoE expression was investigated by qPCR. The association of the MS severity score (MSSS) and APOE rs429358 and rs7412 was assessed across 3237 MS patients using linear regression analyses.

Results

EAE disease course was slightly attenuated in male apoE-deficient (apoE^−/−) mice compared to wildtype mice (cumulative median score: apoE^−/− = 2 [IQR 0.0–4.5]; wildtype = 4 [IQR 1.0–5.0]; n = 10 each group, p = 0.0002). In contrast, EAE was more severe in female apoE^−/− mice compared to wildtype mice (cumulative median score: apoE^−/− = 3 [IQR 2.0–4.5]; wildtype = 3 [IQR 0.0–4.0]; n = 10, p = 0.003). In wildtype animals, apoE expression during the chronic EAE phase was increased in both females and males (in comparison to naïve animals; p < 0.001). However, in MS, we did not observe a significant association between MSSS and rs429358 or rs7412, neither in the overall analyses nor upon stratification for sex.

Conclusions

apoE exerts moderate sex-specific effects on EAE severity. However, the results in the apoE knock-out model are not comparable to effects of polymorphic variants in the human APOE gene, thus pinpointing the challenge of translating findings from the EAE model to the human disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-015-0429-y) contains supplementary material, which is available to authorized users.

Post-training gamma irradiation-enhanced contextual fear memory associated with reduced neuronal activation of the infralimbic cortex

The brain might be exposed to irradiation under a variety of situations, including clinical treatments, nuclear accidents, dirty bomb scenarios, and military and space missions. Correctly recalling tasks learned prior to irradiation is important but little is known about post-learning effects of irradiation. It is not clear whether exposure to X-ray irradiation during memory consolidation, a few hours following training, is associated with altered contextual fear conditioning 24h after irradiation and which brain region(s) might be involved in these effects. Brain immunoreactivity patterns of the immediately early gene c-Fos, a marker of cellular activity was used to determine which brain areas might be altered in post-training irradiation memory retention tasks. In this study, we show that post-training gamma irradiation exposure (1 Gy) enhanced contextual fear memory 24h later and is associated with reduced cellular activation in the infralimbic cortex. Reduced GABA-ergic neurotransmission in parvalbumin-positive cells in the infralimbic cortex might play a role in this post-training radiation-enhanced contextual fear memory.

Hyperlipidemia Alters Regulatory T Cell Function and Promotes Resistance to Tolerance Induction Through Costimulatory Molecule Blockade

Recent work from our laboratory has shown that hyperlipidemia promotes accelerated rejection of vascularized cardiac allografts in mice by inducing anti-donor Th17 reactivity and production of IL-17. Here, we show that hyperlipidemia also affects FoxP3(+) regulatory T cells (Tregs). Hyperlipidemia promotes the development of Tregs that express low levels of CD25. Hyperlipidemia also promotes a decrease in central Tregs and an increase in effector Tregs that appears to account for the increase in the frequency of CD25(low) Tregs. Alterations in Treg subsets also appear to lead to alterations in Treg function. The ability of FoxP3(+) , CD25(high) , CD4(+) Tregs from hyperlipidemic mice to inhibit proliferation of effector T cells stimulated with anti-CD3 and CD28 was reduced when compared with Tregs from control mice. Regulatory T cells isolated from hyperlipidemic recipients exhibit increased activation of Akt, and a reduction in Bim levels that permits the expansion of FoxP3(+) CD25(low) CD4(+) T cells. Hyperlipidemic mice were also resistant to tolerance induction using costimulatory molecule blockade consisting of anti-CD154 and CTLA4Ig, a strategy that requires Tregs. Together, our data suggest that hyperlipidemia profoundly affects Treg subsets and function as well as the ability to induce tolerance.

Hyperlipidemia Promotes Anti-Donor Th17 Responses That Accelerate Allograft Rejection

Hyperlipidemia occurs in 95% of organ transplant recipients, however its effect on organ allograft rejection has not been investigated. We found that induction of hyperlipidemia in mice caused a significant acceleration of rejection of cardiac allografts. Accelerated rejection was associated with an aggressive T cell infiltrate that mediated significant tissue damage as well as increased serum levels of the proinflammatory cytokines IL-2, IL-6, and IL-17. Hyperlipidemic mice had an increased number of Th17 cells in their periphery and rejecting allografts from hyperlipidemic mice contained significant numbers of IL-17 producing T cells that were not detectable in transplants harvested from controls. Neutralization or genetic ablation of IL-17 prolonged survival of cardiac allografts transplanted into hyperlipidemic recipients, suggesting that IL-17 production promotes accelerated rejection. Analysis of alloreactive T cell frequencies directly ex vivo in naïve mice revealed that the frequency of donor reactive IL-17 producing cells in hyperlipidemic was increased prior to antigen exposure, suggesting that hyperlipidemia was sufficient to alter T cell alloreactivity and promote anti-donor Th17 responses on first exposure to antigen. Together, our data suggest that hyperlipidemia alters rejection by altering the types of T cell subsets that respond to donor antigen by promoting Th17 biased anti-donor reactivity.

Child apolipoprotein E gene variants and risk of cerebral palsy: estimation from case-parent triads

OBJECTIVE

To use case-parent triad data to investigate if cerebral palsy (CP) is associated with variants of the APOE gene, the rs59007384 SNP of the TOMM40 gene or combined haplotypes of the two genes.

STUDY DESIGN

DNA was analyzed in buccal swabs from 235 children with CP, their parents and a sibling. The relative risks (RR) with 95% confidence intervals (CI) that the children would have a distribution of APOE genotypes, rs59007384 variants or combined haplotypes deviating from Mendelian inheritance were estimated.

RESULTS

Children with CP were more likely than expected to carry the APOEε3 allele (RR 7.5; CI: 0.99-53.7 for heterozygotes and 10.3; CI: 1.4-79.6 for homozygotes), and to have the haplotype of APOEε3 and rs59007384 G (RR 2.4; CI: 1-5.7 for heterozygotes, RR 3.7; CI: 1.4-9.5 for homozygotes) whereas the distribution was as expected for rs59007384 alone. In the subgroup analyses the findings were confined to children born preterm. Among siblings the distribution of these genes was as expected according to Mendelian inheritance.

CONCLUSION

We speculate that children with APOEε2/APOEε4 alleles are more likely to die following cerebral injury in utero, resulting in a higher than expected proportion of children with CP carrying the APOEε3 allele.

Targeting miR-155 restores abnormal microglia and attenuates disease in SOD1 mice

OBJECTIVE

To investigate miR-155 in the SOD1 mouse model and human sporadic and familial amyotrophic lateral sclerosis (ALS).

METHODS

NanoString microRNA, microglia and immune gene profiles, protein mass spectrometry, and RNA-seq analyses were measured in spinal cord microglia, splenic monocytes, and spinal cord tissue from SOD1 mice and in spinal cord tissue of familial and sporadic ALS. miR-155 was targeted by genetic ablation or by peripheral or centrally administered anti-miR-155 inhibitor in SOD1 mice.

RESULTS

In SOD1 mice, we found loss of the molecular signature that characterizes homeostatic microglia and increased expression of miR-155. There was loss of the microglial molecules P2ry12, Tmem119, Olfml3, transcription factors Egr1, Atf3, Jun, Fos, and Mafb, and the upstream regulators Csf1r, Tgfb1, and Tgfbr1, which are essential for microglial survival. Microglia biological functions were suppressed including phagocytosis. Genetic ablation of miR-155 increased survival in SOD1 mice by 51 days in females and 27 days in males and restored the abnormal microglia and monocyte molecular signatures. Disease severity in SOD1 males was associated with early upregulation of inflammatory genes, including Apoe in microglia. Treatment of adult microglia with apolipoprotein E suppressed the M0-homeostatic unique microglia signature and induced an M1-like phenotype. miR-155 expression was increased in the spinal cord of both familial and sporadic ALS. Dysregulated proteins that we identified in human ALS spinal cord were restored in SOD1(G93A) /miR-155(-/-) mice. Intraventricular anti-miR-155 treatment derepressed microglial miR-155 targeted genes, and peripheral anti-miR-155 treatment prolonged survival.

INTERPRETATION

We found overexpression of miR-155 in the SOD1 mouse and in both sporadic and familial human ALS. Targeting miR-155 in SOD1 mice restores dysfunctional microglia and ameliorates disease. These findings identify miR-155 as a therapeutic target for the treatment of ALS.

Quantitative proteomics identifies host factors modulated during acute hepatitis E virus infection in the swine model

Hepatitis E virus (HEV) causes acute enterically transmitted hepatitis. In industrialized countries, it is a zoonotic disease, with swine being the major reservoir of human HEV contamination. The occurrence and severity of the disease are variable, with clinical symptoms ranging from asymptomatic to self-limiting acute hepatitis, chronic infection, or fulminant hepatitis. In the absence of a robust cell culture system or small-animal models, the HEV life cycle and pathological process remain unclear. To characterize HEV pathogenesis and virulence mechanisms, a quantitative proteomic analysis was carried out to identify cellular factors and pathways modulated during acute infection of swine. Three groups of pigs were inoculated with three different strains of swine HEV to evaluate the possible role of viral determinants in pathogenesis. Liver samples were analyzed by a differential proteomic approach, two-dimensional difference in gel electrophoresis, and 61 modulated proteins were identified by mass spectroscopy. The results obtained show that the three HEV strains replicate similarly in swine and that they modulate several cellular pathways, suggesting that HEV impairs several cellular processes, which can account for the various types of disease expression. Several proteins, such as heterogeneous nuclear ribonucleoprotein K, apolipoprotein E, and prohibitin, known to be involved in other viral life cycles, were upregulated in HEV-infected livers. Some differences were observed between the three strains, suggesting that HEV's genetic variability may induce variations in pathogenesis. This comparative analysis of the liver proteome modulated during infection with three different strains of HEV genotype 3 provides an important basis for further investigations on the factors involved in HEV replication and the mechanism of HEV pathogenesis.

IMPORTANCE

Hepatitis E virus (HEV) is responsible for acute hepatitis, with clinical symptoms ranging from asymptomatic to self-limiting acute hepatitis, chronic infection, or fulminant hepatitis. In industrialized countries, HEV is considered an emerging zoonotic disease, with swine being the principal reservoir for human contamination. The viral and cellular factors involved in the replication and/or pathogenesis of HEV are still not fully known. Here we report that several cellular pathways involved in cholesterol and lipid metabolism or cell survival were modulated during HEV infection in the swine model. Moreover, we observed a difference between the different swine strains, suggesting that HEV's genetic variability could play a role in pathogenesis. We also identified some proteins known to be involved in other viral cycles. Our study provides insight into the mechanisms modulated during HEV infection and constitutes a useful reference for future work on HEV pathogenesis and virulence.

Soluble mediators regulating immunity in early life

Soluble factors in blood plasma have a substantial impact on both the innate and adaptive immune responses. The complement system, antibodies, and anti-microbial proteins and peptides can directly interact with potential pathogens, protecting against systemic infection. Levels of these innate effector proteins are generally lower in neonatal circulation at term delivery than in adults, and lower still at preterm delivery. The extracellular environment also has a critical influence on immune cell maturation, activation, and effector functions, and many of the factors in plasma, including hormones, vitamins, and purines, have been shown to influence these processes for leukocytes of both the innate and adaptive immune systems. The ontogeny of plasma factors can be viewed in the context of a lower effectiveness of immune responses to infection and immunization in early life, which may be influenced by the striking neonatal deficiency of complement system proteins or enhanced neonatal production of the anti-inflammatory cytokine IL-10, among other ontogenic differences. Accordingly, we survey here a number of soluble mediators in plasma for which age-dependent differences in abundance may influence the ontogeny of immune function, particularly direct innate interaction and skewing of adaptive lymphocyte activity in response to infectious microorganisms and adjuvanted vaccines.

Apolipoproteins are associated with new MRI lesions and deep grey matter atrophy in clinically isolated syndromes

OBJECTIVES

There is increasing evidence that serum lipoprotein cholesterol biomarkers are associated with disease progression in clinically isolated syndromes (CIS). Apolipoproteins (Apo) are recognition ligands that mediate the physiological interactions of cholesterol-containing lipoproteins. The objective of this study was to investigate whether serum Apo levels are associated with CIS disease progression.

METHODS

ApoB, ApoAI, ApoAII, ApoE and lipoprotein (a) (Lpa) levels were measured in serum samples obtained prior to the start of treatment from 181 CIS patients (123 women, 58 men, 68% women; mean age: 28.1±SD 8.1 years). All patients were treated with intramuscular interferon-β as part of the prospective study. Clinical and MRI assessments were obtained at baseline, 6, 12 and 24 months after start of interferon-β treatment.

RESULTS

Greater ApoB levels were associated with increased number of new T2 lesions (p<0.001) and increased number of new or enlarging T2 lesions (p<0.001) over 2 years. Each 10 mg/dL of greater baseline ApoB is associated with a 16% increase in the number of new T2 lesions over 2 years. ApoAI, ApoAII, ApoE and Lpa were not associated with T2 lesions. Greater ApoE levels were associated with greater deep grey matter atrophy (partial correlation rp=-0.28, p<0.001). Each 1 mg/dL increment in ApoE levels was associated with a 1% increase in deep grey matter atrophy over 2 years.

CONCLUSIONS

Serum ApoB levels are associated with new lesion accumulation whereas ApoE levels are associated with deep grey matter atrophy in high risk CIS patients treated with interferon β-1a.

Cerebrospinal fluid apolipoprotein E and phospholipid transfer protein activity are reduced in multiple sclerosis; relationships with the brain MRI and CSF lipid variables

Apolipoprotein E (apoE), phospholipid transfer protein (PLTP) activity, lipids, total tau and beta amyloid 1-42 (Aβ₄₂) were measured in cerebrospinal fluid (CSF) from controls (n=38) and multiple sclerosis (MS) patients (n=91). ApoE and PLTP activity were significantly reduced in MS compared to non-inflammatory disease controls (NINDC; p<0.05). In NINDC and MS, apoE correlated with PLTP activity (r_s=0.399 and 0.591, respectively), Aβ₄₂ (r_s= 0.609 and 0.483, respectively), and total tau (r_s=0.748 and 0.380, respectively; all p<0.05). CSF apoE and PLTP significantly contributed to the variance of the normalized brain volume (NBV) and T2 lesion volume in MS (p<0.001 and p<0.05, respectively). ApoE correlated with CSF cholesterol and 24-hydroxycholesterol in all groups; PLTP activity correlated with CSF cholesterol in controls (p<0.05).

The positive correlations of apolipoprotein E with disease activity and related cytokines in systemic lupus erythematosus

Background

The aim of this study is to investigate the expression of apolipoprotein E (apoE) and the relationship between apoE and disease activity of SLE, and the possible effects of glucocorticoid on apoE and other cytokines activities in SLE patients.

Methods

Forty treatment-naïve SLE patients and forty matched healthy controls were studied. All the SLE patients received prednisone 1 mg/kg/day for 28 consecutive days. The sera levels of apoE and related cytokines were evaluated by ELISA. The expression of apoE mRNA in peripheral blood mononuclear cells (PBMCs) was determined by real-time PCR.

Results

Compared with healthy controls, the relative expression levels of ApoE proteins and sera levels were significantly up-regulated in active SLE patients. ApoE sera concentrations positively correlated with SLEDAI, anti-dsDNA antibody and the related cytokines including IL-6, IFN-γ and IL-10, and uncorrelated with the concentration of total cholesterol (TC) and triglyceride (TG) in SLE patients. After 4 weeks prednisone treatment, the relative mRNA expression of apoE and the serum levels of apoE and related cytokines decreased.

Conclusions

ApoE correlated with disease activity and related cytokines in SLE patients. Glucocorticoid can down-regulate the expressions of apoE and related cytokines.

Virtual slide

The virtual slide(s) for this article can be found here:http://www.diagnosticpathology.diagnomx.eu/vs/1646714011077325

Association between apolipoprotein E gene polymorphism and the risk of recurrent pregnancy loss: a meta-analysis

PURPOSE

The association between apolipoprotein E (ApoE) gene polymorphism and the risk of recurrent pregnancy loss (RPL) remains controversial. The present meta-analysis was performed to derive a precise estimate of the relationship.

METHOD(S)

We searched the PubMed, Embase, and Web of Science data- bases for studies related to the association between the ApoE genotype and the risk of RPL. We estimated the summary odds ratio (OR) with 95% confidence interval (CI) to assess the association.

RESULT(S)

Seven studies, including 2,090 RPL cases and 742 control samples, were identified. The results showed a significant association between ApoE E4 mutation and RPL risk (for E4 allele: OR =1.98, 95 %CI =1.14-3.43, P=0.499; for E2E3 vs. E3E3: OR =1.33, 95%CI =1.12-1.42, P=0.008; for E2E4 vs. E3E3: OR =1.26, 95 % CI =1.07-1.49, P=0.005).

CONCLUSION(S)

The meta-analysis suggests an association between ApoE E4 mutation and increased risk of RPL.

Granzyme B degrades extracellular matrix and contributes to delayed wound closure in apolipoprotein E knockout mice

Chronic inflammation and excessive protease activity have a major role in the persistence of non-healing wounds. Granzyme B (GzmB) is a serine protease expressed during chronic inflammation that, in conjunction with perforin, has a well-established role in initiating apoptotic cell death. GzmB is also capable of acting extracellularly, independent of perforin and can degrade several extracellular matrix (ECM) proteins that are critical during wound healing. We used apolipoprotein E (ApoE) knockout (AKO) mice as a novel model of chronic inflammation and impaired wound healing to investigate the role of GzmB in chronic wounds. Wild-type and AKO mice were grown to 7 weeks (young) or 37 weeks (old) of age on a regular chow or high-fat diet (HFD), given a 1-cm diameter full thickness wound on their mid dorsum and allowed to heal for 16 days. Old AKO mice fed a HFD exhibited reduced wound closure, delayed contraction, chronic inflammation and altered ECM remodeling. Conversely, GzmB/ApoE double knockout mice displayed improved wound closure and contraction rates. In addition, murine GzmB was found to degrade both fibronectin and vitronectin derived from healthy mouse granulation tissue. In addition, GzmB-mediated degradation of fibronectin generated a fragment similar in size to that observed in non-healing mouse wounds. These results provide the first direct evidence that GzmB contributes to chronic wound healing in part through degradation of ECM.

Associations between APOE genotypes and disease susceptibility, joint damage and lipid levels in patients with rheumatoid arthritis

OBJECTIVE

Apolipoprotein E (APOE) genotypes are associated with cardiovascular disease (CVD) and lipid levels. In rheumatoid arthritis (RA), an association has been found with disease activity. We examined the associations between APOE genotypes and disease susceptibility and markers of disease severity in RA, including radiographic joint damage, inflammatory markers, lipid levels and cardiovascular markers.

METHOD

A Norwegian cohort of 945 RA patients and 988 controls were genotyped for two APOE polymorphisms. We examined longitudinal associations between APOE genotypes and C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) as well as hand radiographs (van der Heijde Sharp Score(SHS)) in 207 patients with 10 year longitudinal data. Lipid levels, cardiovascular markers and history of CVD were compared across genotypes in a cross sectional study of 136 patients. Longitudinal radiological data of cohorts from Lund and Leiden were available for replication. (N = 935, with 4799 radiographs).

RESULTS

In the Norwegian cohort, associations between APOE genotypes and total cholesterol (TC) and low-density lipoproteins (LDL) were observed (ε2 < ε3/ε3 < ε4, p = 0.03 and p = 0.02, respectively). No association was present for acute phase reactant or CVD markers, but a longitudinal linear association between APOE genotypes and radiographic joint damage was observed (p = 0.007). No association between APOE genotypes and the severity of joint destruction was observed in the Lund and Leiden cohorts, and a meta- analysis combining all data was negative.

CONCLUSION

APOE genotypes are associated with lipid levels in patients with RA, and may contribute to dyslipidemia in some patients. APOE genotypes are not consistently associated with markers of inflammation or joint destruction in RA.

Biomarkers in Multiple Sclerosis: An Up-to-Date Overview

During the last decades, the effort of establishing satisfactory biomarkers for multiple sclerosis has been proven to be very difficult, due to the clinical and pathophysiological complexities of the disease. Recent knowledge acquired in the domains of genomics-immunogenetics and neuroimmunology, as well as the evolution in neuroimaging, has provided a whole new list of biomarkers. This variety, though, leads inevitably to confusion in the effort of decision making concerning strategic and individualized therapeutics. In this paper, our primary goal is to provide the reader with a list of the most important characteristics that a biomarker must possess in order to be considered as reliable. Additionally, up-to-date biomarkers are further divided into three subgroups, genetic-immunogenetic, laboratorial, and imaging. The most important representatives of each category are presented in the text and for the first time in a summarizing workable table, in a critical way, estimating their diagnostic potential and their efficacy to correlate with phenotypical expression, neuroinflammation, neurodegeneration, disability, and therapeutical response. Special attention is given to the "gold standards" of each category, like HLA-DRB1∗ polymorphisms, oligoclonal bands, vitamin D, and conventional and nonconventional imaging techniques. Moreover, not adequately established but quite promising, recently characterized biomarkers, like TOB-1 polymorphisms, are further discussed.

Comparative proteomic profiles indicating genetic factors may involve in hepatocellular carcinoma familial aggregation

Familial aggregation of hepatocellular carcinoma (HCC), the third leading cause of cancer death worldwide, has shown to be a common phenomenon. We investigated the association between the genetic background and HCC familial aggregation. Serum samples were collected from HCC family members and normal control family members for screening the differentially expressed protein peaks with the approach of surface-enhanced laser desorption ionization time-of-flight mass spectrometry. Potential genetically associated protein peaks were selected and further identified by matrix assisted laser desorption ionization-time of flight mass spectrometry. A panel of six protein peaks (m/z 6432.94, 8478.35, 9381.91, 17284.67, 17418.34, and 18111.04) were speculated to reflect the genetic susceptibility of HCC familial aggregation. Three of them (m/z 6432.94, 8478.35, and 9381.91) were selected to identify as the candidate proteins. Nine identified proteins, including mostly apolipoprotein family (ApoA1, ApoA2, ApoC3, ApoE) and serum amyloid A protein (SAA), were found overexpressed in the multiple HCC cases family members. The comparative proteomic profiles have suggested that genetic factors ought to be taken into account for familial aggregation of HCC.

Pulmonary surfactant coating of multi-walled carbon nanotubes (MWCNTs) influences their oxidative and pro-inflammatory potential in vitro

Background

Increasing concern has been expressed regarding the potential adverse health effects that may be associated with human exposure to inhaled multi-walled carbon nanotubes (MWCNTs). Thus it is imperative that an understanding as to the underlying mechanisms and the identification of the key factors involved in adverse effects are gained. In the alveoli, MWCNTs first interact with the pulmonary surfactant. At this interface, proteins and lipids of the pulmonary surfactant bind to MWCNTs, affecting their surface characteristics. Aim of the present study was to investigate if the pre-coating of MWCNTs with pulmonary surfactant has an influence on potential adverse effects, upon both (i) human monocyte derived macrophages (MDM) monocultures, and (ii) a sophisticated in vitro model of the human epithelial airway barrier. Both in vitro systems were exposed to MWCNTs either pre-coated with a porcine pulmonary surfactant (Curosurf) or not. The effect of MWCNTs surface charge was also investigated in terms of amino (−NH₂) and carboxyl (−COOH) surface modifications.

Results

Pre-coating of MWCNTs with Curosurf affects their oxidative potential by increasing the reactive oxygen species levels and decreasing intracellular glutathione depletion in MDM as well as decreases the release of Tumour necrosis factor alpha (TNF-α). In addition, an induction of apoptosis was observed after exposure to Curosurf pre-coated MWCNTs. In triple cell-co cultures the release of Interleukin-8 (IL-8) was increased after exposure to Curosurf pre-coated MWCNTs. Effects of the MWCNTs functionalizations were minor in both MDM and triple cell co-cultures.

Conclusions

The present study clearly indicates that the pre-coating of MWCNTs with pulmonary surfactant more than the functionalization of the tubes is a key factor in determining their ability to cause oxidative stress, cytokine/chemokine release and apoptosis. Thus the coating of nano-objects with pulmonary surfactant should be considered for future lung in vitro risk assessment studies.