Agnieszka Kulczyńska-Przybik

The Relationship between Markers of Inflammation and Degeneration in the Central Nervous System and the Blood-Brain Barrier Impairment in Alzheimer’s Disease

BACKGROUND It is known that YKL-40- a marker of glial inflammation, and VILIP-1- a marker of neuronal injury, reflect functional and structural changes in AD brains, although there is limited data concerning their potential influence on blood-brain barrier (BBB) homeostasis. OBJECTIVE Therefore, the aim of our study was to investigate the relationship between markers of inflammation and degeneration in the central nervous system (CNS) of patients with AD and mild cognitive impairment (MCI) as well as immunological response in CNS and BBB function. METHODS Cerebrospinal fluid (CSF) concentrations of proteins tested were determined in 45 AD patients, 18 MCI subjects, and 23 non-demented controls using ELISA method. RESULTS CSF concentrations of YKL-40 were significantly higher in MCI and AD patients, whereas CSF levels of VILIP-1 were statistically higher in the AD group as compared to the subjects without cognitive deficits. Elevated concentrations of YKL-40 correlated significantly with increased albumin quotient and decreased Aβ42/40 ratio in AD patients and with IgG quotient in the total study group. We did not find a relationship between VILIP-1 and immunological parameters reflecting BBB dysfunction and humoral immune response. CONCLUSION Our findings indicate that YKL-40 may contribute to decreased stability and increased permeability of BBB in AD patients. It is assumed that YKL-40 is implicated in the development of brain barriers, although its precise mechanism of action in the BBB disruption remains unrevealed. Further studies on larger groups of patients are required to confirm our hypothesis.

The Role of Visinin-Like Protein-1 in the Pathophysiology of Alzheimer's Disease

Calcium ions are crucial in the process of information transmission and integration in the central nervous system (CNS). These ions participate not only in intracellular mechanisms but also in intercellular processes. The changes in the concentration of Ca2 + ions modulate synaptic transmission, whereas neuronal activity induces calcium ion waves. Disturbed calcium homeostasis is thought to be one of the main features in the pathophysiology of Alzheimers disease (AD), and AD pathogenesis is closely connected to Ca2 + signaling pathways. The effects of changes in neuronal Ca2 + are mediated by neuronal calcium sensor (NCS) proteins. It has been revealed that NCS proteins, with special attention to visinin-like protein 1 (VILIP-1), might have a connection to the etiology of AD. In the CNS, VILIP-1 influences the intracellular neuronal signaling pathways involved in synaptic plasticity, such as cyclic nucleotide cascades and nicotinergic signaling. This particular protein is implicated in calcium-mediated neuronal injury as well. VILIP-1 also participates in the pathological mechanisms of altered Ca2 + homeostasis, leading to neuronal loss. These findings confirm the utility of VILIP-1 as a useful biomarker of neuronal injury. Moreover, VILIP-1 plays a vital role in linking calcium-mediated neurotoxicity and AD-type pathological changes. The disruption of Ca2 + homeostasis caused by AD-type neurodegeneration may result in the damage of VILIP-1-containing neurons in the brain, leading to increased cerebrospinal fluid levels of VILIP-1. Thus, the aim of this overview is to describe the relationships of the NCS protein VILIP-1 with the pathogenetic factors of AD and neurodegenerative processes, as well as its potential clinical usefulness as a biomarker of AD. Moreover, we describe the current and probable therapeutic strategies for AD, targeting calcium-signaling pathways and VILIP-1.

YKL-40 as a Potential Biomarker and a Possible Target in Therapeutic Strategies of Alzheimer’s Disease

Background: Growing body of evidence suggests that the pathogenesis of Alzheimer’s disease (AD), a progressing neurodegenerative condition, is not limited to the neuronal compartment, but also involves various immunological mechanisms. Insoluble Aβ aggregates in the brain can induce the activation of microglia, resulting in the synthesis of proinflammatory mediators, which further can stimulate astrocytic expression of YKL-40. Therefore, the aim of the current review is to present up-to-date data about the role of YKL-40 as a biomarker of AD as well as the possibility of therapeutic strategies targeting neuroinflammation. Objective/Methods: We searched PubMed articles for the terms “YKL-40”, “neurodegeneration”, “neuroinflammation” and “Alzheimer’s disease”, and included papers focusing on this review’s scope. Results: Recent studies indicate that CSF concentrations of YKL-40 were significantly higher in AD patients than in cognitively normal individuals and correlated with dementia biomarkers, such as tau proteins and amyloid beta. Determination of YKL-40 CSF concentration may be also helpful in differentiation between types of dementia and in the distinction of patients in the stable phase of MCI from those who progressed to dementia. Moreover, significantly increased levels of YKL-40 mRNA were found in AD brains in comparison with non-demented controls. Additionally, it was suggested that anti-inflammatory treatment might relief the symptoms of AD and slow its progression. Conclusion: Based on the recent knowledge, YKL-40 might be useful as a possible biomarker in the diagnosis and prognosis of AD. Modulation of risk factors and targeting of immune mechanisms, including systemic inflammation could lead to future preventive or therapeutic strategies for AD.

Serum chemokine CXCL-8 as a better biomarker for diagnosis and prediction of pancreatic cancer than its specific receptor CXCR-2, CRP and classical tumor markers (CA 19-9 and CEA)

Introduction Novel biomarkers are critically needed to improve the management of patients with pancreatic cancer (PC). Objectives We aimed to evaluate the clinical usefulness of serum CXCL8 in relation to its specific receptor CXCR2 in the diagnosis and prediction of PC compared with classic tumor markers (carbohydrate antigen 19-9 [CA 19-9] and carcinoembryonic antigen [CEA]) and C-reactive protein (CRP). Patients and methods The study included 76 subjects: 42 patients with PC and 34 healthy volunteers. Serum protein levels were measured by immunological methods. Results Serum CXCL8 and CXCR2 concentrations were significantly higher in PC patients compared with healthy controls, similarly to classic tumor markers and CRP. CXCL8 levels were significantly elevated in patients with lymph node metastasis compared with individuals without nodal involvement. The diagnostic sensitivity, accuracy, negative predictive value, and areas under the receiver operating characteristic curves for CXCL8 were higher than those for CXCR2, CRP, CA 19-9, and CEA. Moreover, serum CXCL8 was the only significant predictor of PC risk. Conclusions Our findings indicate the significance of the CXCL8-CXCR2 axis in the pathogenesis of PC. Serum CXCL8 is emerging as the strongest candidate for a potential PC biomarker among all proteins tested.

The relationships among monocyte subsets, miRNAs and inflammatory cytokines in patients with acute myocardial infarction

BACKGROUND Acute myocardial infarction (AMI) causes irreversible myocardial damage and release of inflammatory mediators, including cytokines, chemokines and miRNAs. We aimed to investigate changes in the levels of cytokines (IL-6, TNF-α and IL-10), miRNAs profiles (miR-146 and miR-155) and distribution of different monocyte subsets (CD14++CD16-, CD14++CD16+, CD14+CD16++) in the acute and post-healing phases of AMI. METHODS In eighteen consecutive AMI patients (mean age 56.78 ± 12.4 years, mean left ventricle ejection fraction - LVEF: 41.9 ± 9.8%), treated invasively, monocyte subsets frequencies were evaluated (flow cytometry), cytokine concentrations were analyzed (ELISA) as well as plasma miRNAs were isolated twice - on admission and after 19.2 ± 5.9 weeks of follow-up. Measurements were also performed among healthy volunteers. RESULTS AMI patients presented significantly decreased frequencies of classical cells in comparison to healthy controls (median 71.22% [IQR: 64.4-79.04] vs. 84.35% [IQR: 81.2-86.7], p = 0.001) and higher percent of both intermediate and non-classical cells, yet without statistical significance (median 6.54% [IQR: 5.14-16.64] vs. 5.87% [IQR: 4.48-8.6], p = 0.37 and median 5.99% [IQR: 3.39-11.5] vs. 5.26% [IQR: 3.62-6.2], p = 0.42, respectively). In AMI patients both, analyzed plasma miRNA concentrations were higher than in healthy subjects (miR-146: median 5.48 [IQR: 2.4-11.27] vs. 1.84 [IQR: 0.87-2.53], p = 0.003; miR-155: median 25.35 [IQR: 8.17-43.15] vs. 8.4 [IQR: 0.08-16.9], p = 0.027, respectively), and returned back to the values found in the control group in follow-up. miR-155/miR-146 ratio correlated with the frequencies of classical monocytes (r=0.6, p = 0.01) and miR-155 correlated positively with the concentration of inflammatory cytokines - IL-6 and TNF-α. CONCLUSIONS These results may suggest cooperation of both pro-inflammatory and anti-inflammatory signals in AMI in order to promote appropriate healing of the infarcted myocardium.

Pathophysiological implications of actin-free Gc-globulin concentration changes in blood plasma and cerebrospinal fluid collected from patients with Alzheimer’s disease and other neurological disorders

BACKGROUND The extracellular actin scavenging system (EASS) is composed of plasma Gc-globulin and gelsolin, and is responsible for the elimination of toxic actin from the bloodstream. OBJECTIVES In this study, we assessed the actin-free Gc-globulin concentrations in blood plasma and cerebrospinal fluid (CSF) obtained from subjects with neurodegenerative and inflammatory diseases of the central nervous system (CNS) as well as in a control group. MATERIAL AND METHODS Using an enzyme-linked immunosorbent assay (ELISA), we measured the actinfree Gc-globulin concentrations in blood plasma and CSF obtained from subjects diagnosed with Alzheimers disease (AD) (n = 20), amyotrophic lateral sclerosis (ALS) (n = 12), multiple sclerosis (MS) (n = 42), tick-borne encephalitis (TBE) (n = 12), and from a control group (n = 20). RESULTS The concentrations of free Gc-globulin in plasma collected from patients diagnosed with AD (509.6 ±87.6 mg/L) and ALS (455.5 ±99.8 mg/L) did not differ significantly between each other, but were significantly higher compared to the reference group (311.7 ±87.5 mg/L) (p < 0.001 and p < 0.006, respectively) as well as to MS (310.8 ±66.6 mg/L) (p < 0.001 and p < 0.001, respectively) and TBE (256.7 ±76 mg/L) (p < 0.001 and p < 0.003, respectively). In CSF collected from patients diagnosed with AD and ALS, the concentrations of free Gc-globulin were 2.6 ±1.1 mg/L and 2.7 ±1.9 mg/L, respectively. They did not differ significantly between each other and were significantly higher compared to the reference group (1.5 ±0.9 mg/L) (p < 0.005 and p < 0.041, respectively). Interestingly, in patients with AD, significantly higher values of Gcglobulin were detected compared to multiple sclerosis patients (1.7 ±0.9 mg/L) (p < 0.013). CONCLUSIONS Higher concentrations of free Gc-globulin in blood plasma and CSF collected from patients suffering from neurodegenerative diseases may indicate a potential role of this protein in their pathogenesis, and represent a potential tool for the diagnosis of CNS diseases.

CONCENTRATION OF CHITINASE 3-LIKE PROTEIN (YKL-40) IN THE CEREBROSPINAL FLUID OF PATIENTS WITH ALZHEIMER’S DISEASE

tion, vitality, and ability to carry out activities of daily living. Methods:Study subjects were chosen from patients that hospitalized our department between April 2012 andMarch 2015, presenting for “forgetfulness”. Those who consented were photographed from the front and in profile from both sides. Five experienced geriatricians (greater than 10 years’ experience) then determined the “Perceived Age” of each participant based on these photographs. CGAs (Comprehensive Geriatric Assessments), and Quality of Life assessments (SF8) were also performed. Results:The study included 29 patients with Alzheimer’s disease, 20 patients with aMCI, and 12 patients with unimpaired cognition. 20 patients were male, 41 female, and the average age was 80 6 7 years. Average MMSE was 22.16 5.7, average GDS 5.46 3.3, and average Vitality index 9.0 6 1.0. “Chronological age” had a correlation coefficient, R, of 0.34 (p1⁄40.005) with MMSE and 0.30 (p1⁄40.02) with the Vitality index. However, “Perceived age” had an R of 0.40 (p1⁄40.002) with MMSE and 0.55 (p<0.0001) with the Vitality index, showing that “Perceived age” was more strongly correlated with these two markers than with “Chronological age”. Conclusions:The study results indicated that individuals whose “Perceived age” was higher than their “Chronological age”, were likely to have lower cognition and a lower Vitality index.

CONCENTRATION OF VISININ-LIKE PROTEIN-1 (VILIP-1) IN THE CEREBROSPINAL FLUID OF PATIENTS WITH ALZHEIMER'S DISEASE

assay range were done using the same sample set. As the assay concept and procedure were unchanged, the other analytical performance parameters (e.g. Specificity, interfering substances, ...) were considered to be unaffected. Results: The Limit of Detection (LOD 1⁄4 mean blank + 2*Stdev) of the updated assay, based on 28 measurements of the blank (1⁄4 sample diluent) was determined to be 65.2 pg/ml. The intraand inter-assay variability were found to be 4.6% (range 0.8% 11.0%) and 7.8% (range 1.4% 18.0%) respectively based on the results of the CSF samples tested over four different runs. CSF sample concentrations determined with the updated product aligned well with those of the previous version. The assay range, defined by the lower limit of quantification and upper limit of quantification, ranged from 225 pg/ml to 1452 pg/ml, based on the results from the sample set described above. Conclusions: The updated INNOTEST b-Amyloid 1-42 performance data complied with the standardization requirements of the AD diagnostic community. The improvements to the product were assessed to preserve the clinical utility of the CSF Amyloid-b 1-42 results.