The proton-sensing receptors TDAG8 and GPR4 are differentially expressed in human and mouse oligodendrocytes: Exploring their role in neuroinflammation and multiple sclerosis

Acidosis is one of the hallmarks of demyelinating central nervous system (CNS) lesions in multiple sclerosis (MS). The response to acidic pH is primarily mediated by a family of G protein-coupled proton-sensing receptors: OGR1, GPR4 and TDAG8. These receptors are inactive at alkaline pH, reaching maximal activation at acidic pH. Genome-wide association studies have identified a locus within the TDAG8 gene associated with several autoimmune diseases, including MS. Accordingly, we here found that expression of TDAG8, as opposed to GPR4 or OGR1, is upregulated in MS plaques. This led us to investigate the expression of TDAG8 in oligodendrocytes using mouse and human in vitro and in vivo models. We observed significant upregulation of TDAG8 in human MO3.13 oligodendrocytes during maturation and in response to acidic conditions. However, its deficiency did not impact normal myelination in the mouse CNS, and its expression remained unaltered under demyelinating conditions in mouse organotypic cerebellar slices. Notably, our data revealed no expression of TDAG8 in primary mouse oligodendrocyte progenitor cells (OPCs), in contrast to its expression in primary human OPCs. Our investigations have revealed substantial species differences in the expression of proton-sensing receptors in oligodendrocytes, highlighting the limitations of the employed experimental models in fully elucidating the role of TDAG8 in myelination and oligodendrocyte biology. Consequently, the study does not furnish robust evidence for the role of TDAG8 in such processes. Nonetheless, our findings tentatively point towards a potential association between TDAG8 and myelination processes in humans, hinting at a potential link between TDAG8 and the pathophysiology of MS and warrants further research.

3D-printed extraction devices fabricated from silica particles suspended in acrylate resin

In recent years, there has been an increasing worldwide interest in the use of alternative sample preparation methods. Digital light processing (DLP) is a 3D printing technique based on using UV light to form photo-curable resin layer upon layer, which results in a printed shape. This study explores the application of this technique for the development of novel drug extraction devices in analytical chemistry. A composite material consisting of a photocurable resin and C18-modified silica particles was employed as a sorbent device, demonstrating its effectiveness in pharmaceutical analysis. Apart from estimating optimal printing parameters, microscopic examination of the material surface, and sorbent powder to resin ratio, the extraction procedure was also optimised. Optimisation included the type and amount of sample matrix additives, desorption solvent, sorption and desorption times, and proper number of sorbent devices needed in extraction protocol. To demonstrate this method's applicability for sample analysis, the solid-phase extraction followed by gas chromatography coupled with mass spectrometry (SPE-GC-MS) method was validated for its ability to quantify benzodiazepine-type drugs. This evaluation confirmed good linearity in the concentration range of 50-1000 ng/mL, with R2 values being 0.9932 and 0.9952 for medazepam and diazepam, respectively. Validation parameters proved that the presented method is precise (with values ranging in-between 2.98 %-7.40 %), and accurate (88.81 % to 110.80 %). A negative control was also performed to investigate possible sorption properties of the resin itself, proving that the addition of C18-modified silica particles significantly increases the extraction efficiency and repeatability. The cost-effectiveness of this approach makes it particularly advantageous for single-use scenarios, eliminating the need for time-consuming sorbent-cleaning procedures, common in traditional solid-phase extraction techniques. Future optimisation opportunities include refining sorbent size, shape, and geometry to achieve lower limits of quantification. As a result of these findings, 3D-printed extraction devices can serve as a viable alternative to commercially available SPE or solid-phase microextraction (SPME) protocols for studying new sample preparation approaches.

Comparison of the level of physical activity after the COVID-19 pandemic in Poland, Slovakia and the Czech Republic

BACKGROUND

The COVID-19 pandemic was associated with limited physical activity (PA) of most of the world's population. This cross-sectional prospective study aimed to assess the levels of PA of university students in Poland, Czech Republic and Slovakia after COVID-19 using the International Physical Activity Questionnaire Short Form (IPAQ-SF).

METHODS

A total of 2635 students completed questionnaires regarding their PA levels using the IPAQ-SF between September and December 2022.

RESULTS

PA measured by metabolic equivalent of task (MET) scores, varied between the three countries: Slovakia median MET-minutes/week score 4459.9; Czech Republic 3838.8 Poland 3567.1. The results of the post hoc analysis revealed there were significant differences in MET-minutes/week values between the Czech Republic and Poland (p < 0.035) as well as between the Czech Republic and Slovakia (p < 0.037). The analysis of energetic expenditure during walking revealed that students from the Czech Republic and Slovakia had higher median MET-min/weeks values (Czech 2284.1; Slovak 2467.1) compared to their Polish (1536.1) peers (p < 0.001). Polish cohort presented with significantly higher body mass index (BMI) (p < 0.001) than Czech and Slovak groups (BMI Czech: 22.3; Slovak 22.8; Polish 23.8).

CONCLUSIONS

Significant differences in PA levels between the Czech Republic, Poland, and Slovakia university students were identified. Slovakia showed the highest median PA measured as a MET score, and Poland showed the lowest. Compared to available pre-COVID studies it seems the total level of PA in the observed cohorts has not returned to the pre-COVID levels and students remain less active.

The impaired distribution of adenosine deaminase isoenzymes in multiple sclerosis plasma and cerebrospinal fluid

Background

Adenosine deaminase (ADA) via two isoenzymes, ADA1 and ADA2, regulates intra- and extracellular adenosine concentrations by converting it to inosine. In the central nervous system (CNS), adenosine modulates the processes of neuroinflammation and demyelination that together play a critical role in the pathophysiology of multiple sclerosis (MS). Except for their catalytic activities, ADA isoenzymes display extra-enzymatic properties acting as an adhesion molecule or a growth factor.

Aims

This study aimed to explore the distribution and activity of ADA1 and ADA2 in the plasma and the CSF of MS patients as well as in the human brain microvascular endothelial cells (HBMEC), human brain vascular pericytes and human astrocytes.

Methods and results

The enzyme assay following reverse phase-high performance liquid chromatography (HPLC) analysis was used to detect the ADA1 and ADA2 activities and revealed an increased ratio of ADA1 to ADA2 in both the plasma and the CSF of MS patients. Plasma ADA1 activity was significantly induced in MS, while ADA2 was decreased in the CSF, but significance was not reached. The brain astrocytes, pericytes and endothelial cells revealed on their surface the activity of ADA1, with its basal level being five times higher in the endothelial cells than in the astrocytes or the pericytes. In turn, ADA2 activity was only observed in pericytes and endothelial cells. Stimulation of the cells with pro-inflammatory cytokines TNFα/IL17 for 18 h decreased intracellular nucleotide levels measured by HPLC only in pericytes. The treatment with TNFα/IL17 did not modulate cell-surface ATP and AMP hydrolysis nor adenosine deamination in pericytes or astrocytes. Whereas in endothelial cells it downregulated AMP hydrolysis and ADA2 activity and upregulated the ADA1, which reflects the ADA isoenzyme pattern observed here in the CSF of MS patients.

Conclusion

In this study, we determined the impaired distribution of both ADA isoenzymes in the plasma and the CSF of patients with MS. The increased ADA1 to ADA2 ratio in the CSF and plasma may translate to unfavorable phenotype that triggers ADA1-mediated pro-inflammatory mechanisms and decreases ADA2-dependent neuroprotective and growth-promoting effects in MS.

Mechanoreceptor Piezo1 Is Downregulated in Multiple Sclerosis Brain and Is Involved in the Maturation and Migration of Oligodendrocytes in vitro

Mechanical properties of the brain such as intracranial pressure or stiffness of the matrix play an important role in the brain’s normal physiology and pathophysiology. The physical properties are sensed by the cells through mechanoreceptors and translated into ion currents which activate multiple biochemical cascades allowing the cells to adapt and respond to changes in their microenvironment. Piezo1 is one of the first identified mechanoreceptors. It modulates various central nervous system functions such as axonal growth or activation of astrocytes. Piezo1 signaling was also shown to play a role in the pathophysiology of Alzheimer’s disease. Here, we explore the expression of the mechanoreceptor Piezo1 in human MO3.13 oligodendrocytes and human MS/non-MS patients’ brains and investigate its putative effects on oligodendrocyte proliferation, maturation, and migration. We found that Piezo1 is expressed in human oligodendrocytes and oligodendrocyte progenitor cells in the human brain and that its inhibition with GsMTx4 leads to an increment in proliferation and migration of MO3.13 oligodendrocytes. Activation of Piezo1 with Yoda-1 induced opposite effects. Further, we observed that expression of Piezo1 decreased with MO3.13 maturation in vitro. Differences in expression were also observed between healthy and multiple sclerosis brains. Remarkably, the data showed significantly lower expression of Piezo1 in the white matter in multiple sclerosis brains compared to its expression in the white matter in healthy controls. There were no differences in Piezo1 expression between the white matter plaque and healthy-appearing white matter in the multiple sclerosis brain. Taken together, we here show that Piezo1-induced signaling can be used to modulate oligodendrocyte function and that it may be an important player in the pathophysiology of multiple sclerosis.

EBI2 is expressed in glial cells in multiple sclerosis lesions, and its knock-out modulates remyelination in the cuprizone model

EBI2 receptor regulates the immune system, and in multiple, sclerosis is upregulated in the central nervous system infiltrating lymphocytes. In newborn EBI2-deficient mice, myelin development is delayed, and its persistent antagonism inhibits remyelination in chemically demyelinated organotypic cerebellar slices. We used the cuprizone model of multiple sclerosis to elucidate the role of central nervous system-expressed EBI2 in de- and remyelination. The wild-type and EBI2 knock-out mice were fed 0.2% cuprizone in chow for 5 weeks and allowed to recover on a normal diet for 2 weeks. The data showed less efficient recovery of myelin, attenuated oligodendrocyte loss, fewer astrocytes and increased total cholesterol levels in the EBI2 knock-out mice after recovery. Moreover, the wild-type mice upregulated EBI2 expression after recovery confirming the involvement of EBI2 signalling during recovery from demyelination in the cuprizone model. The pro-inflammatory cytokine levels were at comparable levels in the wild-type and EBI2 knock-out mice, with only minor differences in TNFα and IL1β levels either at peak or during recovery. The neuroinflammatory signalling molecules, Abl1 kinase and NFКB1 (p105/p50) subunit, were significantly downregulated in the EBI2 knock-out mice at peak of disease. Immunohistochemical investigations of EBI2 receptor distribution in the central nervous system (CNS) cells in multiple sclerosis (MS) brain revealed strong expression of EBI2 in astrocytes and microglia inside the plaques implicating glia-expressed EBI2 in multiple sclerosis pathophysiology. Taken together, these findings demonstrate the involvement of EBI2 signalling in the recovery from demyelination rather than in demyelination and as such warrant further research into the role of EBI2 in remyelination.

Inflation expectations quantification with fuzzy control system

The inflation expectations of economic agents are one of the most important variables for central banks and monetary policy conduct, but such expectations are not directly observable. Consumers’ expectations are examined in qualitative surveys. The key task is to transform consumers’ survey responses into quantitative proxies of expectations. In this examination, we investigate an alternative method to quantify consumers’ inflation expectations using fuzzy rule-based systems. In order to generate rules in the learning phase, we compare two methods: the Wang-Mendel method based on space partition and the subtractive clustering method. The learning data are information about past inflation and consumers’ opinions as expressed in surveys. The system is built and tested on data from January 2002 to June 2019 for non-euro member states of the EU. The fuzzy rules-based system returns results that outperform a benchmark—the standard quantification procedure—in terms of correlation with a raw approximation of consumer expectations, which is survey balance statistics. The results are robust regarding the benchmark choice. We find the method more promising for economies with lower stability, as it gives more room for the training phase of the algorithm application.

EBI2 Is Temporarily Upregulated in MO3.13 Oligodendrocytes during Maturation and Regulates Remyelination in the Organotypic Cerebellar Slice Model

The EBI2 receptor regulates the immune system and is expressed in various immune cells including B and T lymphocytes. It is also expressed in astrocytes in the central nervous system (CNS) where it regulates pro-inflammatory cytokine release, cell migration and protects from chemically induced demyelination. Its signaling and expression are implicated in various diseases including multiple sclerosis, where its expression is increased in infiltrating immune cells in the white matter lesions. Here, for the first time, the EBI2 protein in the CNS cells in the human brain was examined. The function of the receptor in MO3.13 oligodendrocytes, as well as its role in remyelination in organotypic cerebellar slices, were investigated. Human brain sections were co-stained for EBI2 receptor and various markers of CNS-specific cells and the human oligodendrocyte cell line MO3.13 was used to investigate changes in EBI2 expression and cellular migration. Organotypic cerebellar slices prepared from wild-type and cholesterol 25-hydroxylase knock-out mice were used to study remyelination following lysophosphatidylcholine (LPC)-induced demyelination. The data showed that EBI2 receptor is present in OPCs but not in myelinating oligodendrocytes in the human brain and that EBI2 expression is temporarily upregulated in maturing MO3.13 oligodendrocytes. Moreover, we show that migration of MO3.13 cells is directly regulated by EBI2 and that its signaling is necessary for remyelination in cerebellar slices post-LPC-induced demyelination. The work reported here provides new information on the expression and role of EBI2 in oligodendrocytes and myelination and provides new tools for modulation of oligodendrocyte biology and therapeutic approaches for demyelinating diseases.

A novel method for rapid and quantitative detection of bisphenol A in urine

Bisphenol A (BPA) is classified as an endocrine disruptor (ED) and it can interact with variety of hormone receptors leading to hormonal disruption and increased risk of various adverse health effects. Reducing human exposure to BPA is one of the main challenges of public health, as it is constantly present in daily life. A low-cost and commonly applied method to enable determination of BPA in the patient's body has yet to be developed. Currently available techniques are expensive, time-consuming, and require access to highly equipped analytical chemistry laboratories. Here we describe a fast and cheap engineered lateral flow assay of our design, to detect of BPA in urine samples. The technology not only provides an opportunity to perform rapid medical diagnostics without the need for an access to the central laboratory but also a means for self-diagnosis by the patient. The addition of β-glucuronidase improves the sensitivity of detection as it releases the free BPA from glucuronide complexes in urine. This invention may become a demonstrated analytical means for lowering human exposure to BPA and probably also to other EDs and consequently, may be useful in decrease of the risk for several lifestyle diseases.

Changes in daily life reduce indoor exposure to selected endocrine disruptors in the home environment: a pilot intervention study

Increasing prevalence of lifestyle diseases raised global awareness about health consequences of human exposure to endocrine disruptors (EDs): synthetic chemicals that mimic natural hormones and affect the biochemical and endocrine balance. As home environment is one of the main sources of the exposure to xenobiotics - especially for pregnant women, infants and young children - health organizations emphasize the need of implementing lifestyle changes to protect human health and child development. The aim of this study was to evaluate the effectiveness of introducing changes in daily life in lowering the exposure to selected EDs in the indoor home environment. Twenty-six healthy volunteers from 9 households from Gdansk (Poland) were enrolled and their home- and lifestyle-related exposure to EDs was analyzed using a designed questionnaire and algorithm. Urine and dust samples were collected before and after introducing the recommended lifestyle changes. The concentrations of selected EDs in the samples were determined using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). This pilot study confirmed the ubiquity of harmful chemicals in the home environment and the importance of exposure related to a daily routine. Importantly, it proved that lifestyle modifications implemented by participants led to a significant decrease in both, their home-related exposure to EDs, as well as in urine concentrations of these chemicals. It also demonstrated a need for determining EDs exposure and introducing lifestyle changes as a useful tool for prevention of lifestyle-related diseases.

Determination of trace levels of eleven bisphenol A analogues in human blood serum by high performance liquid chromatography-tandem mass spectrometry

Chemicals showing structural or functional similarity to bisphenol A (BPA), commonly called BPA analogues, have recently drawn scientific attention due to their common industrial and commercial application as a substitute for BPA. In the European Union, the use of BPA has been severely restricted by law due to its endocrine disrupting properties. Unfortunately, it seems that all BPA analogues show comparable biological activity, including hormonal disruption, toxicity and genotoxicity. Until now, the knowledge about human exposure to BPA analogues is scarce, mainly due to the lack of the data concerning their occurrence in human derived biological samples. This study presents the development of an analytical method for determination of trace levels of eleven BPA analogues in human blood serum samples. The method involves fast and simple liquid-liquid extraction, using low sample and solvent volumes. Chromatographic separation of analytes was optimized using one-factor-at-a-time approach (mobile phase composition, gradient shape, chromatographic column selection, separation temperature, etc.). The method allows for effective separation of the analytes, even in the case of configurational isomers (bisphenol M and bisphenol P). The calibration curves for all analytes were linear in the range tested. The limits of detection and quantitation were in the range of 0.0079÷0.039ng/mL and 0.024÷0.12ng/mL respectively. Compound-dependent recovery values were in the rage of 88÷138%. Matrix effects were mitigated with the help of matrix-matched calibration curves prepared for every batch of samples. Results obtained after the analysis of 245 real human blood serum samples indicate that human beings are exposed to different BPA analogues, that are present in the environment and in common, daily use products.

EBI2 regulates pro-inflammatory signalling and cytokine release in astrocytes

The endogenous oxysterol 7α, 25-dihydroxycholesterol (7α25HC) ligand activates the G protein-coupled receptor EBI2 to regulate T cell-dependant antibody response and B cell migration. We have demonstrated that EBI2 is expressed in human and mouse astrocytes, that 7α25HC induces intracellular signalling and astrocyte migration, and that EBI2 plays a role in the crosstalk between astrocytes and macrophages. Recently, we demonstrate that EBI2 regulates myelin development and inhibits LPC-induced demyelination. Here, we show that 7α25HC inhibits LPS- and IL17/TNF-induced pro-inflammatory cytokine release in astrocytes. We observe the following: 1. Human astrocytes treated with IL17/TNF increases the nuclear translocation of NFκB, which is attenuated by pre-treatment with 7α25HC; 2. IL17/TNF increases cell impedance in human astrocytes, which is also attenuated by pre-treatment with 7α25HC; 3. The EBI2 antagonist NIBR189 inhibits these effects of 7α25HC, supporting the role of EBI2; 4. in vivo data corroborate these in vitro findings, showing that EBI2 knock-out (KO) animals display enhanced pro-inflammatory cytokine in response to LPS challenge, in the brain. These results demonstrate a role for oxysterol/EBI2 signalling in attenuating the response of astrocytes to pro-inflammatory signals as well as limiting the levels of pro-inflammatory cytokines in the brain.

EBI2 receptor regulates myelin development and inhibits LPC-induced demyelination

BACKGROUND

The G protein-coupled receptor EBI2 (Epstein-Barr virus-induced gene 2) is activated by 7α, 25-dihydroxycholesterol (7α25HC) and plays a role in T cell-dependant antibody response and B cell migration. Abnormal EBI2 signaling is implicated in a range of autoimmune disorders; however, its role in the CNS remains poorly understood.

METHODS

Here we characterize the role of EBI2 in myelination under normal and pathophysiological conditions using organotypic cerebellar slice cultures and EBI2 knock-out (KO) animals.

RESULTS

We find that MBP expression in brains taken from EBI2 KO mice is delayed compared to those taken from wild type (WT) mice. In agreement with these in vivo findings, we show that antagonism of EBI2 reduces MBP expression in vitro. Importantly, we demonstrate that EBI2 activation attenuates lysolecithin (LPC)-induced demyelination in mouse organotypic slice cultures. Moreover, EBI2 activation also inhibits LPC-mediated release of pro-inflammatory cytokines such as IL6 and IL1β in cerebellar slices.

CONCLUSIONS

These results, for the first time, display a role for EBI2 in myelin development and protection from demyelination under pathophysiological conditions and suggest that modulation of this receptor may be beneficial in neuroinflammatory and demyelinating disorders such as multiple sclerosis.

The Role of the Oxysterol/EBI2 Pathway in the Immune and Central Nervous Systems

Oxysterols are pleiotropic messengers interacting with multiple receptor systems. One of the cognate receptors for oxysterols is EBI2, a G protein-coupled receptor highly expressed in the cells of the immune system. Here we discuss the receptor's role in the adapted immunity and inflammation as well as the receptor's expression and function in the CNS with the focus on astrocytes. We also discuss expression and signalling of oxysterol-producing enzymes such as CH25H and CYP7B1 in the CNS and the immune system. These steps will help to elucidate a possible role for this pathway in the physiology of the central and peripheral nervous system and its possible link to human disease.

Polish Society of Endocrinology Position statement on endocrine disrupting chemicals (EDCs)

With the reference to the position statements of the Endocrine Society, the Paediatric Endocrine Society, and the European Society of Paediatric Endocrinology, the Polish Society of Endocrinology points out the adverse health effects caused by endocrine disrupting chemicals (EDCs) commonly used in daily life as components of plastics, food containers, pharmaceuticals, and cosmetics. The statement is based on the alarming data about the increase of the prevalence of many endocrine disorders such as: cryptorchidism, precocious puberty in girls and boys, and hormone-dependent cancers (endometrium, breast, prostate). In our opinion, it is of human benefit to conduct epidemiological studies that will enable the estimation of the risk factors of exposure to EDCs and the probability of endocrine disorders. Increasing consumerism and the industrial boom has led to severe pollution of the environment with a corresponding negative impact on human health; thus, there is great necessity for the biomonitoring of EDCs in Poland.

The EBI2 signalling pathway plays a role in cellular crosstalk between astrocytes and macrophages

EBI2 is a G protein-coupled receptor activated by oxysterol 7α, 25-dihydroxycholesterol (7α25HC) and regulates T cell-dependant antibody response and B cell migration. We recently found EBI2 is expressed in human astrocytes, regulates intracellular signalling and modulates astrocyte migration. Here, we report that LPS treatment of mouse astrocytes alters mRNA levels of EBI2 and oxysterols suggesting that the EBI2 signalling pathway is sensitive to LPS-mediated immune challenge. We also find that conditioned media obtained from LPS-stimulated mouse astrocytes induces macrophage migration, which is inhibited by the EBI2 antagonist NIBR189. These results demonstrate a role for the EBI2 signalling pathway in astrocytes as a sensor for immune challenge and for communication with innate immune cells such as macrophages.

Pathway specific modulation of S1P1 receptor signalling in rat and human astrocytes

BACKGROUND AND PURPOSE

The sphingosine 1-phosphate receptor subtype 1 (S1P1R) is modulated by phosphorylated FTY720 (pFTY720), which causes S1P1R internalization preventing lymphocyte migration thus limiting autoimmune response. Studies indicate that internalized S1P1Rs continue to signal, maintaining an inhibition of cAMP, thus raising question whether the effects of pFTY720 are due to transient initial agonism, functional antagonism and/or continued signalling. To further investigate this, the current study first determined if continued S1P1R activation is pathway specific.

EXPERIMENTAL APPROACH

Using human and rat astrocyte cultures, the effects of S1P1R activation on cAMP, pERK and Ca(2+) signalling was investigated. In addition, to examine the role of S1P1R redistribution on these events, a novel biologic (MNP301) that prevented pFTY720-mediated S1P1R redistribution was engineered.

KEY RESULTS

The data showed that pFTY720 induced long-lasting S1P1R redistribution and continued cAMP signalling in rat astrocytes. In contrast, pFTY720 induced a transient increase of Ca(2+) in astrocytes and subsequent antagonism of Ca(2+) signalling. Notably, while leaving pFTY720-induced cAMP signalling intact, the novel MNP301 peptide attenuated S1P1R-mediated Ca(2+) and pERK signalling in cultured rat astrocytes.

CONCLUSIONS AND IMPLICATIONS

These findings suggested that pFTY720 causes continued cAMP signalling that is not dependent on S1P1R redistribution and induces functional antagonism of Ca(2+) signalling after transient stimulation. To our knowledge, this is the first report demonstrating that pFTY720 causes continued signalling in one pathway (cAMP) versus functional antagonism of another pathway (Ca(2+)) and which also suggests that redistributed S1P1Rs may have differing signalling properties from those expressed at the surface.

Health risk of exposure to Bisphenol A (BPA)

Bisphenol A (BPA) belongs to chemicals that are produced in large quantities worldwide. It is commonly used as monomer in polycarbonate synthesis, plasticizer in the production of epoxy resins, as well as an additive for the elimination of surfeit of hydrochloric acid during the polyvinyl chloride (PVC) production. BPA is not only used in the production of plastics intended to a direct contact with food, including plastic packaging and kitchenware, but also in inner coatings of cans and jar caps. There are various routes of human exposure to this substance such as oral, by inhalation and transdermal. The main sources of exposure to BPA include food packaging and dust, dental materials, healthcare equipment, thermal paper, toys and articles for children and infants. BPA is metabolized in the liver to form bisphenol A glucuronide and mostly in this form is excreted with urine. Due to its phenolic structure BPA has been shown to interact with estrogen receptors and to act as agonist or antagonist via estrogen receptor (ER) dependent signalling pathways. Therefore, BPA has been shown to play a role in the pathogenesis of several endocrine disorders including female and male infertility, precocious puberty, hormone dependent tumours such as breast and prostate cancer and several metabolic disorders including polycystic ovary syndrome (PCOS). Because of the constant, daily exposure and its tendency to bio-accumulation, BPA seems to require special attention such as biomonitoring. This observation should include clinical tests of BPA concentration in the urine, which is not only one of the best methods of evaluation of the exposure to this compound, but also the dependence of the daily intake of BPA and the risk of some endocrine disorders.

The selective anti-IL17A monoclonal antibody secukinumab (AIN457) attenuates IL17A-induced levels of IL6 in human astrocytes

The family of interleukin 17 receptors (IL17Rs), subtypes IL17RA-IL17RE, is targeted by the group of pro-inflammatory IL17 cytokines (IL17A-F) and moreover the newly developed anti-IL17A antibody secukinumab (AIN457) has shown promise in Phase II trials in multiple sclerosis. Here, we show that human astrocytes, isolated from a fetal cerebral cortex, express IL17RA and IL17RC and in vitro treatment with IL17A increases protein levels of IL6 in human astrocytes, which is enhanced in the presence of TNFα, as determined by homogeneous time resolved fluorescence. Studies on acutely isolated mouse astrocytes are comparable to human astrocytes although the protein levels of IL6 are lower in mouse astrocytes, which also show a lower response to IL17F and IL1β in promoting IL6 levels. In human astrocytes, IL17A and TNFα also induce mRNA expression of IL6, IL8 and the Th17 cytokines CXCL1, CXCL2, and CCL20, with little effect on Th1 cytokines CXCL9, CXCL10, and CXCL11. The effects of IL17A are associated with nuclear translocation of the NF-κB transcription factor, as determined by immunocytochemistry, where treatment of human astrocytes with the inhibitors of the NF-κB pathway and with secukinumab inhibits the IL17A and IL17A/TNFα-induced increase in nuclear translocation of NF-κB and levels of IL6. Taken together the data shows that IL17A signaling plays a key role in regulating the levels of cytokines, such as IL6, in human astrocytes via a mechanism that involves NF-κB signaling and that selective inhibition of IL17A signaling attenuates levels of pro-inflammatory molecules in astrocytes.

EBI2 regulates intracellular signaling and migration in human astrocyte

The G protein-coupled receptor EBI2 (Epstein-Barr virus-induced gene 2) is activated by 7α, 25-dihydroxycholesterol (7α25HC) and plays a role in T cell-dependant antibody response and B cell migration. Aberrant EBI2 signaling is implicated in a range of autoimmune disorders however its role in the CNS remains unknown. Here we characterize the functional role of EBI2 in GLIA cells using primary human astrocytes and EBI2 knockout animals. We find human and mouse astrocytes express EBI2 and the enzymes necessary for synthesis and degradation of 7α25HC. In astrocytes, EBI2 activation stimulates ERK phosphorylation, Ca(2+) signaling and induces cellular migration. These results, for the first time, demonstrate a role for EBI2 in astrocyte function and suggest that modulation of this receptor may be beneficial in neuroinflammatory disorders.

Bisphenol A (BPA) and its potential role in the pathogenesis of the polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is the most common and the most heterogeneous endocrine disorder in premenopausal women. Apart from signs of hyperandrogenism such as acne, hirsutism and hair loss, women with PCOS usually present with menstrual irregularities and fertility problems.Additionally, they are often characterized by impaired glucose tolerance, which usually leads to the development of type 2 diabetes mellitus (T2DM). This review article describes current and novel approach to the pathomechanisms of PCOS and the potential role of an endocrine disrupting chemical ("endocrine disruptor" - ED) - bisphenol A (BPA), which is commonly used as a plasticizer and due to its molecular structure can interact with estrogen receptors (ERs). Recent observations point to the higher levels of BPA in biological fluids of women with PCOS and its role in the pathogenesis of hyperandrogenism and hyperinsulinemia. It seems that mother's exposure to BPA during pregnancy may also lead to the development of PCOS in the female offspring.

[Planning disorders in men with schizophrenia and in men with localized frontal lobe lesions]

AIM

Planning disorders have been observed in people with frontal lobe lesions for many decades. There's also growing body of evidence of frontal dysfunction in people with schizophrenia. The aim of this study is to compare the planning abilities in men with schizophrenia, men with localized frontal lobe lesions and healthy men.

METHOD

A sample of 90 men participated in the study. They were divided into three groups: men with schizophrenia (n = 30), men with localized frontal lobe lesions (n = 30) and healthy men (n = 30) as a control group. Planning abilities were assessed with a clinical trial based on Tower of London task.

RESULTS

Significant differences in ToL measures were found between controls and men with schizophrenia (Trials solved: p < 0.01; Trials solved perfectly: p < 0.05; Execution time: p < 0.001) and between controls and men with frontal lobe lesions (Trials solved: p < 0.001; Thinking time: p < 0.05; Execution time: p < 0.001). No significant differences were found between schizophrenia and frontal lobe lesion groups.

CONCLUSIONS

Similar deficits in planning and solving problems, which require planning, may be observed in men with schizophrenia and men with frontal lobe lesions. In both groups time spent on thinking is less effective than in healthy men. Not only quantitative, but also qualitative assessment should be carried when examining patients' performance on Tower of London task.

TRACER. A new approach to comparative modeling that combines threading with free-space conformational sampling

A new approach to comparative modeling of proteins, TRACER, is described and benchmarked against classical modeling procedures. The new method unifies true three-dimensional threading with coarse-grained sampling of query protein conformational space. The initial sequence alignment of a query protein with a template is not required, although a template needs to be somehow identified. The template is used as a multi-featured fuzzy three-dimensional scaffold. The conformational search for the query protein is guided by intrinsic force field of the coarse-grained modeling engine CABS and by compatibility with the template scaffold. During Replica Exchange Monte Carlo simulations the model chain representing the query protein finds the best possible structural alignment with the template chain, that also optimizes the intra-protein interactions as approximated by the knowledge based force field of CABS. The benchmark done for a representative set of query/template pairs of various degrees of sequence similarity showed that the new method allows meaningful comparative modeling also for the region of marginal, or non-existing, sequence similarity. Thus, the new approach significantly extends the applicability of comparative modeling.

TRACER. A new approach to comparative modeling that combines threading with free-space conformational sampling

A new approach to comparative modeling of proteins, TRACER, is described and benchmarked against classical modeling procedures. The new method unifies true three-dimensional threading with coarse-grained sampling of query protein conformational space. The initial sequence alignment of a query protein with a template is not required, although a template needs to be somehow identified. The template is used as a multi-featured fuzzy three-dimensional scaffold. The conformational search for the query protein is guided by intrinsic force field of the coarse-grained modeling engine CABS and by compatibility with the template scaffold. During Replica Exchange Monte Carlo simulations the model chain representing the query protein finds the best possible structural alignment with the template chain, that also optimizes the intra-protein interactions as approximated by the knowledge based force field of CABS. The benchmark done for a representative set of query/template pairs of various degrees of sequence similarity showed that the new method allows meaningful comparative modeling also for the region of marginal, or non-existing, sequence similarity. Thus, the new approach significantly extends the applicability of comparative modeling.

Arterial stiffness in relation to subclinical atherosclerosis

BACKGROUND

Increased arterial stiffness or arteriosclerosis, represents a physiological part of ageing. Atherosclerosis is a process that does not affect the arterial bed uniformly but has a variable local distribution and is frequently superimposed on stiffened vessels. We therefore addressed the question of whether any correlation exists between the general characteristics of arterial stiffness or wave reflection and subclinical atherosclerosis as assessed by carotid intima-media thickness (IMT) in a sample of healthy subjects.

METHODS

A total of 116 healthy subjects (mean age 55 years, 43 female) were evaluated. Arterial stiffness and wave reflection was assessed with the use of digital volume pulse analysis (DVP) and pulse wave analysis (PWA). Subclinical atherosclerosis was assessed by measurement of IMT.

RESULTS

Stiffness Index (SI(DVP)), the measure of general arterial stiffness correlated significantly with IMT (r = 0.37, P < 0.01). IMT correlated significantly with age (r = 0.5, P < 0.0001), waist to hip ratio (WHR) (r = 0.39, P < 0.0001) and mean blood pressure (BPmean) (r = 0.4, P < 0.0001). IMT did not correlate with measures of wave reflection. SI(DVP) correlated significantly with age (r = 0.32, P < 0.005), WHR (r = 0.36, P < 0.0001), BPmean (r = 0.36, P < 0.0001) and measurements of wave reflection. However analysis of a model which included variables that significantly influenced SI(DVP) and IMT, such as age, WHR and mean BP showed that arterial stiffness is not independently associated with subclinical atherosclerosis.

CONCLUSIONS

The indices of subclinical atherosclerosis, arterial stiffness and wave reflection, indicate different aspects of vascular status in otherwise healthy subjects.

Denatured proteins and early folding intermediates simulated in a reduced conformational space

Conformations of globular proteins in the denatured state were studied using a high-resolution lattice model of proteins and Monte Carlo dynamics. The model assumes a united-atom and high-coordination lattice representation of the polypeptide conformational space. The force field of the model mimics the short-range protein-like conformational stiffness, hydrophobic interactions of the side chains and the main-chain hydrogen bonds. Two types of approximations for the short-range interactions were compared: simple statistical potentials and knowledge-based protein-specific potentials derived from the sequence-structure compatibility of short fragments of protein chains. Model proteins in the denatured state are relatively compact, although the majority of the sampled conformations are globally different from the native fold. At the same time short protein fragments are mostly native-like. Thus, the denatured state of the model proteins has several features of the molten globule state observed experimentally. Statistical potentials induce native-like conformational propensities in the denatured state, especially for the fragments located in the core of folded proteins. Knowledge-based protein-specific potentials increase only slightly the level of similarity to the native conformations, in spite of their qualitatively higher specificity in the native structures. For a few cases, where fairly accurate experimental data exist, the simulation results are in semiquantitative agreement with the physical picture revealed by the experiments. This shows that the model studied in this work could be used efficiently in computational studies of protein dynamics in the denatured state, and consequently for studies of protein folding pathways, i.e. not only for the modeling of folded structures, as it was shown in previous studies. The results of the present studies also provide a new insight into the explanation of the Levinthal's paradox.

Denatured proteins and early folding intermediates simulated in a reduced conformational space

Conformations of globular proteins in the denatured state were studied using a high-resolution lattice model of proteins and Monte Carlo dynamics. The model assumes a united-atom and high-coordination lattice representation of the polypeptide conformational space. The force field of the model mimics the short-range protein-like conformational stiffness, hydrophobic interactions of the side chains and the main-chain hydrogen bonds. Two types of approximations for the short-range interactions were compared: simple statistical potentials and knowledge-based protein-specific potentials derived from the sequence-structure compatibility of short fragments of protein chains. Model proteins in the denatured state are relatively compact, although the majority of the sampled conformations are globally different from the native fold. At the same time short protein fragments are mostly native-like. Thus, the denatured state of the model proteins has several features of the molten globule state observed experimentally. Statistical potentials induce native-like conformational propensities in the denatured state, especially for the fragments located in the core of folded proteins. Knowledge-based protein-specific potentials increase only slightly the level of similarity to the native conformations, in spite of their qualitatively higher specificity in the native structures. For a few cases, where fairly accurate experimental data exist, the simulation results are in semiquantitative agreement with the physical picture revealed by the experiments. This shows that the model studied in this work could be used efficiently in computational studies of protein dynamics in the denatured state, and consequently for studies of protein folding pathways, i.e. not only for the modeling of folded structures, as it was shown in previous studies. The results of the present studies also provide a new insight into the explanation of the Levinthal's paradox.

Functional dissection of Escherichia coli trigger factor: unraveling the function of individual domains

In Escherichia coli, the ribosome-associated chaperone Trigger Factor (TF) promotes the folding of newly synthesized cytosolic proteins. TF is composed of three domains: an N-terminal domain (N), which mediates ribosome binding; a central domain (P), which has peptidyl-prolyl cis/trans isomerase activity and is involved in substrate binding in vitro; and a C-terminal domain (C) with unknown function. We investigated the contributions of individual domains (N, P, and C) or domain combinations (NP, PC, and NC) to the chaperone activity of TF in vivo and in vitro. All fragments comprising the N domain (N, NP, NC) complemented the synthetic lethality of Deltatig DeltadnaK in cells lacking TF and DnaK, prevented protein aggregation in these cells, and cross-linked to nascent polypeptides in vitro. However, DeltatigDeltadnaK cells expressing the N domain alone grew more slowly and showed less viability than DeltatigDeltadnaK cells synthesizing either NP, NC, or full-length TF, indicating beneficial contributions of the P and C domains to TF's chaperone activity. In an in vitro system with purified components, none of the TF fragments assisted the refolding of denatured d-glyceraldehyde-3-phosphate dehydrogenase in a manner comparable to that of wild-type TF, suggesting that the observed chaperone activity of TF fragments in vivo is dependent on their localization at the ribosome. These results indicate that the N domain, in addition to its function to promote binding to the ribosome, has a chaperone activity per se and is sufficient to substitute for TF in vivo.

Chronopharmacokinetics of amitriptyline in rats

The circadian changes in absorption, tissue distribution and elimination of amitriptyline after single intravenous (i.v.) and intragastric (i.g.) administration, as well as the differences in pharmacokinetic profile after multiple i.g. administration (at 10:00 and 22:00 h) during a 12 h dosing interval, were investigated. The circadian changes of pharmacokinetic parameters of amitriptyline such as AUC (serum and tissues), clearance (i.v. and i.g.), volume of distribution, biological half-life and bioavailability were estimated. Acrophases for clearance appeared between 19:00 and 21:00 h; the bioavailability was highest during the dark phase at around 04:00 h. Higher values of AUC in serum were observed at the beginning of the light phase. A circadian rhythm of tissue distribution (AUC, K(D)) of amitriptyline with acrophase in the dark phase was observed for brain (12 h period), lung and liver (24 h), but not for heart or kidney. After single (i.v. and i.g.) amitriptyline administration, concentrations of its major metabolite, nortriptyline, were negligible; however, after ten doses, nortriptyline serum and tissue levels were similar to the concentrations of the parent drug with higher values during the day (light phase).

[Neurological aspects of two patients with non-mosaic and mosaic polysomy of the X and Y chromosomes]

Clinical features were compared of a patient with the 48,XXYY karyotype and a case of 47,XXY/48,XXYY mosaicism. In the former patient tremor of the upper extremities of unclear aetiology was present. In both cases epilepsy was suspected. Similarly as in other cases of 48,XXYY karyotype the first patient had skeletal anomalies, abnormalities of dermatoglyphics and personality changes. These features are rarely found in Klinefelter syndrome. The differences in relation to the syndrome were less evident in the case of mosaicism 47,XXY/48,XXYY.

Effect of ethanol dose on its chronopharmacokinetics in the rats

Circadian changes in the elimination of ethanol after its administration in the rats in two doses: low (1.5 g/kg) and high (4.5 g/kg) were investigated. Circadian rhythm in ethanol pharmacokinetics (AUC, CLpo, t1/2) was observed after the low dose but not after the high one. The maximum rate of elimination was in the dark (active) phase at 1 am. The maximum value of clearance was related to the minimum value of AUC. Although the maximum and the minimum values of Vmax and KM differed essentially the diurnal variation were not observed.

N-acetyl-S-(1,2,2-trichlorovinyl)-L-cysteine and 2,2,2-trichloroethanol: two novel metabolites of tetrachloroethene in humans after occupational exposure

The excretion of tetrachloroethene metabolites in urine was studied in occupationally exposed workers to identify and quantify metabolites formed by glutathione conjugation and by cytochrome P450 oxidation of tetrachloroethene in humans. The glutathione conjugation pathway has been implicated in the chronic toxicity and possible tumorigenicity of tetrachloroethene to the kidney in rats. The biosynthesis of S-(1,2,2-trichlorovinyl)glutathione and N-acetyl-S-(1,2,2-trichlorovinyl)-L-cysteine in humans had not been demonstrated. In this study, we investigated the biotransformation of tetrachloroethene in humans occupationally exposed during dry cleaning. Tetrachloroethene concentrations in the air of the dry cleaning shop were 50 +/- 4 ppm; two individuals were exposed for 8 hr daily and two individuals were exposed for 4 hr daily. In urine samples collected from the individuals at the beginning and at the end of the work week, N-acetyl-S-(1,2,2-trichlorovinyl)-L-cysteine and 2,2,2-trichloroethanol as tetrachloroethene metabolites in humans were identified by GC/MS. The concentrations of N-acetyl-S-(1,2,2-trichlorovinyl)-L-cysteine in the urine of the individuals were not significantly different at the start and at the end of the work week; however, concentrations of both N-acetyl-S-(1,2,2-trichlorovinyl)-L-cysteine and 2,2,2-trichloro compounds (trichloroacetic acid and 2,2,2-trichloroethanol) as a marker for cytochrome P450-mediated metabolism were proportional to the length of daily tetrachloroethene exposure. A remarkable difference in the excretion pattern of 2,2,2-trichloro compounds, the major tetrachloroethene metabolites, was observed. Trichloroacetic acid and 2,2,2-trichloroethanol were present in the urine of two of the exposed individuals. Only 2,2,2-trichloroethanol was identified as a major urinary tetrachloroethene metabolite in two other individuals who did not excrete detectable amounts of trichloroacetic acid. The obtained results indicate that humans also have the ability to biosynthesize nephrotoxic glutathione S-conjugates from tetrachloroethene; however, when compared with rats, the human capacity for the biosynthesis of N-acetyl-S-(1,2,2-trichlorovinyl)-L-cysteine seems to be lower.

Inhibitory action of cimetidine on antipyrine metabolism

The influence of cimetidine on the activity of microsomal enzymes in vivo using the simple one-sample antipyrine test was investigated. The calculated antipyrine clearance unequivocally indicates the dose-dependent effect of cimetidine on the microsomal biotransformation of antipyrine. The IC50 of cimetidine inhibitory effect was 39.9 mg/kg. The duration of the effect was approximately 12 h and the lowest antipyrine clearance was observed 0.5 h following cimetidine administration. The in vivo results were confirmed by an in vitro study. Km for global metabolic processes of antipyrine in vitro was 1.3 mM. Vmax 9.1 nM/mg/min for control was decreased to 3.1 nM/mg/min after addition of cimetidine (4 mM). The inhibition constant of cimetidine determined by the method of Dixon, was 2.8 mM. Inhibition of antipyrine metabolism by cimetidine was noncompetitive.

Circadian changes in the elimination of amitriptyline in rats

The circadian changes in elimination and absorption of amitriptyline after its intravenous and intragastric administration in rats were investigated. The values of such parameters as: AUC, MRT, t1/2, Cl, Vd, k(a) for amitriptyline change in the circadian rhythm. The fastest elimination of amitriptyline was observed in the dark phase (the acrophases for clearance were ca. 11 p.m. for iv administration and ca. 10 p.m. for po administration). The maximal value of clearance corresponds to the minimal values of MRT and t1/2. The acrophase for the constant absorption rate (po) falls at 7 p.m. Cyclic changes were not observed as far as the bioavailability is concerned.

[Subarachnoid hemorrhage from ruptured intracranial aneurysm and surgical procedures as a cause of neuropsychological disorders]

The results of preoperative and postoperative examinations in 30 patients operated on for ruptured intracranial aneurysm are reported. The examinations included neuropsychological, neurological and EEG assessment. The agreements and divergencies in the assessment of the condition of the patients by these methods were analysed suggesting the necessity of consideration of psychological disturbances as a consequence of the disease in the general evaluation of the therapeutic results in such cases.

[Neuropsychological catamnesis in cases of intracranial aneurysm]

The authors analyzed the results of neuropsychological examinations in 30 cases in which a single intracranial aneurysm had been excluded from circulation. The neuropsychological assessment of the higher mental functions was carried out using a set of tests of A. R. Luria in all cases and repeated thrice, comparing the results with those of neurological examination and EEG. The condition of the patients was evaluated using a three-grade scale. In the group of cases with aneurysms of the anterior communicating artery a divergence was observed between the results of neuropsychological examination and neurological examination. The patients achieved not infrequently, very good and good Grades in neurological examination and unsatisfactory in neuropsychological examination and unsatisfactory in neuropsychological examination. A similar divergence was observed also when the aneurysm was situated in other cerebral arteries. On the other hand, considerable similarities were found between the neuropsychological assessment and the result of EEG (with regard to the location, of disturbances and their intensity). Neuropsychological examination made possible detection and determination of the dynamic development of defects in the functions of higher psychic activities inaccessible for routine neurological examination, but having a very important effect on the everyday functions of the patient.