Multi-target potential of newly designed tacrine-derived cholinesterase inhibitors: Synthesis, computational and pharmacological study.

Simple and scalable synthetic approach was used for the preparation of thirteen novel tacrine derivatives consisting of tacrine and N-aryl-piperidine-4-carboxamide moiety connected by a five-methylene group linker. An anti-Alzheimer disease (AD) potential of newly designed tacrine derivatives was evaluated against two important AD targets, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). In vitro pharmacological evaluation showed strong ChE inhibitory activity of all compounds, with IC50 values ranging from 117.5 to 455 nM for AChE and 34 to 324 nM for BuChE. As a representative of the series with the best cytotoxicity / ChE inhibitory activity ratio, expressed as the selectivity index (SI), 2-chlorobenzoyl derivative demonstrated mixed-type inhibition on AChE and BuChE, suggesting binding to both CAS and PAS of the enzymes. It also exhibited antioxidant capacity and neuroprotective potential against amyloid-ß (Aß) toxicity in the culture of neuron-like cells. In-depth computational analysis corroborated well with in vitro ChE inhibition, illuminating that all compounds exhibit significant potential in targeting both enzymes. Molecular dynamics (MD) simulations revealed that 2-chlorobenzoyl derivative, created complexes with AChE and BuChE that demonstrated sufficient stability throughout the observed MD simulation. Computationally predicted ADME properties indicated that these compounds should have good blood-brain barrier (BBB) permeability, an important factor for CNS-targeting drugs. Overall, all tested compounds showed promising pharmacological behavior, highlighting the multi-target potential of 2-chlorobenzoyl derivative which should be further investigated as a new lead in the drug development process.

Seroepidemiology of Human Parvovirus B19 Infection among the Population of Vojvodina, Serbia, over a 16-Year Period (2008-2023).

This study aimed to estimate the serological status and dynamic changes in the prevalence of Parvovirus B19 (PVB19) antibodies within the general population residing in the northern part of the Republic of Serbia (Province of Vojvodina) during a 16-year period. Serum samples were analyzed for Human PVB19-specific IgM and IgG antibodies using enzyme-linked immunosorbent assay (ELISA). Throughout the study period, the overall seroprevalence was 49.51%. Approximately 10% of patients exhibited a serologic profile positive for PVB19 IgM antibodies. Notably, seroprevalence varied significantly, ranging from 9.12% in the pediatric cohort (ages 1-4 years) to 65.50% in the adult demographic (40-59 years old). Seroprevalence was higher (51.88%) among women compared to men (42.50%). Immunologically naive pregnant women in the age groups 26-36 and 36-45 years had 45% (OR = 0.55, 95% CI: 0.31-1.00) and 52% (OR = 0.48; 95% CI: 0.24-0.94) lower odds of having negative IgM and IgG compared to those in age group 16-25 years old. Improved knowledge of the epidemiology of PVB19 may assist clinicians in the differential diagnosis of PVB19 clinical manifestations. The PVB19 detection is particularly important for monitoring individuals in risk groups such as women of reproductive age, medical staff, patients with hematological disorders, and those with immunodeficiency.

Pharmacological Akt and JNK Kinase Inhibitors 10-DEBC and SP600125 Potentiate Anti-Glioblastoma Effect of Menadione and Ascorbic Acid Combination in Human U251 Glioblastoma Cells.

Glioblastoma multiforme (GBM) is the most lethal primary brain tumor in adults, characterized by a highly invasive nature and therapy resistance. Combination of menadione and ascorbic acid (AA+MD) exerts strong ROS-mediated anti-GBM activity in vitro. The objective of this study was to improve AA+MD anti-GBM potential by modulating the activity of Akt and c-Jun N-terminal kinase (JNK), molecules with an important role in GBM development. The effects of Akt and JNK modulation on AA+MD toxicity in U251 human glioblastoma cells were assessed by cell viability assays, flow cytometry, RNA interference and plasmid overexpression, and immunoblot analysis. The AA+MD induced severe oxidative stress, an early increase in Akt phosphorylation followed by its strong inhibition, persistent JNK activation, and U251 cell death. Small molecule Akt kinase inhibitor 10-DEBC enhanced, while pharmacological and genetic Akt activation decreased, AA+MD-induced toxicity. The U251 cell death potentiation by 10-DEBC correlated with an increase in the combination-induced autophagic flux and was abolished by genetic autophagy silencing. Additionally, pharmacological JNK inhibitor SP600125 augmented combination toxicity toward U251 cells, an effect linked with increased ROS accumulation. These results indicate that small Akt and JNK kinase inhibitors significantly enhance AA+MD anti-GBM effects by autophagy potentiation and amplifying deleterious ROS levels.

Effects of early life overnutrition and hyperandrogenism on spatial learning and memory in a rat model of polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is a complex disorder characterized by endocrine and metabolic abnormalities such as obesity and insulin resistance. PCOS is also associated with psychiatric disorders and cognitive impairment. The animal model of PCOS was induced by treating rats with 5α-dihydrotestosterone (5α-DHT) and additionally modified to induce adiposity by litter size reduction (LSR). Spatial learning and memory were assessed using the Barnes Maze test, and striatal markers of synaptic plasticity were analyzed. Striatal insulin signaling was estimated by the levels of insulin receptor substrate 1 (IRS1), its inhibitory phosphorylation at Ser307, and glycogen synthase kinase-3α/ß (GSK3α/ß) activity. Both LSR and DHT treatment significantly decreased striatal protein levels of IRS1, followed by increased GSK3α/ß activity in small litters. Results of the behavioral study showed that LSR had a negative effect on learning rate and memory retention, whereas DHT treatment did not induce impairment in memory formation. While protein levels of synaptophysin, GAP43, and postsynaptic density protein 95 (PSD-95) were not altered by the treatments, DHT treatment induced an increase in phosphorylation of PSD-95 at Ser295 in both normal and small litters. This study revealed that LSR and DHT treatment suppressed insulin signaling by downregulating IRS1 in the striatum. However, DHT treatment did not have an adverse effect on learning and memory, probably due to compensatory elevation in pPSD-95-Ser295, which had a positive effect on synaptic strength. This implies that hyperandrogenemia in this setting does not represent a threat to spatial learning and memory, opposite to the effect of overnutrition-related adiposity.

Diagnostic value of urine qRT-PCR for the diagnosis of West Nile virus neuroinvasive disease.

Short and low-level viremia and virorachia, antibody cross-reactivity, IgM persistence, and inaccessibility of neutralization test, make laboratory diagnosis of West Nile virus (WNV) infection difficult. Recent investigations imply that WNV is excreted in urine longer and at higher concentrations compared to blood. The detection of WNV nucleic acid in cerebrospinal fluid (CSF), serum, and urine samples collected from 41 patients with suspected WNV neuroinvasive disease, was done by real-time RT-PCR assay. CSF and serum samples were also serologically tested using anti-WNV IgM/IgG ELISA kits. WNV infection was confirmed in 46.3% of patients by positive WNV RNA results in serum and/or CSF samples. The WNV RNA testing of urine allowed confirmation of 31.7% more cases. No association between WNV RNA urine positivity and age, gender, or the day of sample collection was found. The urine qRT-PCR can be a valuable diagnostic test for confirmation of probable cases of WNV neuroinvasive disease.

Incremental costs of hospital-acquired infections in COVID-19 patients in an adult intensive care unit of a tertiary hospital from a low-resource setting.

BACKGROUND: Hospital-acquired infections (HAIs) are a global public health problem and put patients at risk of complications, including death. HAIs increase treatment costs, but their financial impact on Serbia's healthcare system is unknown. Our goal was to assess incremental costs of HAIs in a tertiary care adult intensive care unit (ICU) that managed COVID-19 patients. METHODS: A retrospective study from March 6th to December 31st, 2020 included patients with microbiologically confirmed COVID-19 (positive rapid antigen test or real-time polymerase chain reaction) treated in the ICU of the Teaching Hospital for Infectious and Tropical Diseases, University Clinical Centre of Serbia. Demographic and HAI-specific data acquired in our ICU were collected, including total and stratified medical costs (services, materials, laboratory testing, medicines, occupancy costs). Median total and stratified costs were compared in relation to HAI acquisition. Linear regression modelling was used to assess incremental costs of HAIs, adjusted for age, biological sex, prior hospitalisation, Charlson Comorbidity Index (CCI), and Glasgow Coma Scale (GCS) on admission. Outcome variables were length of stay (LOS) in days and mortality. RESULTS: During the study period, 299 patients were treated for COVID-19, of which 214 were included. HAIs were diagnosed in 56 (26.2%) patients. Acinetobacter spp. was the main pathogen in respiratory (38, 45.8%) and bloodstream infections (35, 42.2%), the two main HAI types. Median total costs were significantly greater in patients with HAIs (€1650.4 vs. €4203.2, p < 0.001). Longer LOS (10.0 vs. 18.5 days, p < 0.001) and higher ICU mortality (51.3% vs. 89.3%, p < 0.001) were seen if HAIs were acquired. Patients with ≥ 2 HAIs had the highest median total costs compared to those without HAIs or with a single HAI (€1650.4 vs. €3343.4 vs. €7336.9, p < 0.001). Incremental costs in patients with 1 and ≥ 2 HAIs were €1837.8 (95% CI 1257.8-2417.7, p < 0.001) and €5142.5 (95% CI 4262.3-6022.7, p < 0.001), respectively. CONCLUSIONS: This is the first economic evaluation of HAIs in Serbia, showing significant additional costs to our healthcare system. HAIs prolong LOS and influence ICU mortality rates. Larger economic assessments are needed to enhance infection control practices.

Human papillomavirus-specific antibody status among unvaccinated subjects in the region of Vojvodina, Serbia.

OBJECTIVES: The aim of the study was to evaluate the immune status of young people from the Vojvodina province, Serbia, through the detection of IgG antibodies specific for the L1 protein of HPV types 6, 11, 16, and 18 contained in quadrivalent vaccine. METHODS: The study enrolled 514 healthy persons of both genders, aged between 18 and 30 years. All potential participants were informed about the project's aims by trained interviewers before venous blood collection. Also, participants completed a specially designed anonymous questionnaire to identify socio-demographic characteristics and individual behaviours associated with HPV seroprevalence. VPL HPV L1-specific IgG antibodies were measured using a semi-quantitative HPV IgG ELISA kit (Dia.Pro, Italy). RESULTS: A total of 472 (91.8%) young subjects had no detectable antibodies against high- and low-risk HPV types covered by the quadrivalent vaccine. A slightly higher number of seropositive individuals were detected in the age group of 26-30 years compared to younger than 25. Multivariate analysis showed that the number of lifetime sexual partners was the most powerful predictor of HPV seropositivity (OR = 3.483, 95% CI: 1.294-9.379). CONCLUSIONS: Obtained data point out low levels of naturally induced HPV-specific serum antibodies among the target population in the Vojvodina province. The present work highlights the significance and potential benefits of HPV vaccination. Routine HPV vaccination should be the public health priority in our country and should be included in the national immunization programme as soon as possible.

Titrating Avidity of Yeast-Displayed Proteins Using a Transcriptional Regulator.

Yeast surface display is a valuable tool for protein engineering and directed evolution; however, significant variability in the copy number (i.e., avidity) of displayed variants on the yeast cell wall complicates screening and selection campaigns. Here, we report an engineered titratable display platform that modulates the avidity of Aga2-fusion proteins on the yeast cell wall dependent on the concentration of the anhydrotetracycline (aTc) inducer. Our design is based on a genomic Aga1 gene copy and an episomal Aga2-fusion construct both under the control of an aTc-dependent transcriptional regulator that enables stoichiometric and titratable expression, secretion, and display of Aga2-fusion proteins. We demonstrate tunable display levels over 2-3 orders of magnitude for various model proteins, including glucose oxidase enzyme variants, mechanostable dockerin-binding domains, and anti-PDL1 affibody domains. By regulating the copy number of displayed proteins, we demonstrate the effects of titratable avidity levels on several specific phenotypic activities, including enzyme activity and cell adhesion to surfaces under shear flow. Finally, we show that titrating down the display level allows yeast-based binding affinity measurements to be performed in a regime that avoids ligand depletion effects while maintaining small sample volumes, avoiding a well-known artifact in yeast-based binding assays. The ability to titrate the multivalency of proteins on the yeast cell wall through simple inducer control will benefit protein engineering and directed evolution methodology relying on yeast display for broad classes of therapeutic and diagnostic proteins of interest.

Negative trend in seroprevalence of anti-toxoplasma gondii IgG antibodies among the general population of the province of Vojvodina, Serbia, 2008-2021.

This study aimed to estimate dynamic changes in seroprevalence of Toxoplasma gondii within the general population living in the northern part of the Republic of Serbia (Province of Vojvodina) during a 14-year period. The differences in prevalence of anti-toxoplasma antibodies were analyzed in correlation with age, gender, residential area (rural/urban) and meteorological factors. In this cohort retrospective study, 24,440 subjects between 1 and 88 years old were enrolled. To determine the presence of T. gondii-specific IgM and IgG antibodies in serum samples, commercially available ELISA kits were used (Euroimmun, Luebeck, Germany). During the study period, the overall T. gondii seroprevalence was 23.5%. The seroprevalence continuously decreased over time from 31.7% in 2008 to 20.4% in 2021 (0.81% per year, p < 0.001). Approximately 2% of patients had a serologic profile positive for both anti-Toxoplasma IgG and IgM antibodies. The seroprevalence was higher (28.87%) among men compared to women (24.28%), while urban residents (24.94%) had lower seroprevalence than the rural population (28.17%). A statistically significant negative correlation (r = -0.559) was found between serologic profile of patients positive for both T. gondii IgG and IgM antibodies and the annual mean air temperature. No significant association was observed between seropositivity to T. gondii infection and examined meteorological factors. These data could be useful to national and regional health authorities to create an optimal health policy to reduce rate of T. gondii infections.

Detection and Molecular Characterization of Rotavirus Infections in Children and Adults with Gastroenteritis from Vojvodina, Serbia.

Rotaviruses (RV) are the leading cause of gastroenteritis in infants, young children, and adults, responsible for serious disease burden. In the period 2012-2018, a cross-sectional study was conducted using stool samples collected from patients with acute gastroenteritis from Vojvodina, Serbia. We described age and gender distribution, as well as seasonal patterns of RV prevalence. Out of 1853 included stool samples, RV was detected in 29%. Hospitalized children between 1-2 years old were especially affected by RV infection (45%). The highest prevalence of infection was observed during the colder, winter/spring months. We compared sequenced representative G and P genotypes circulating in Serbia with vaccine strains and determined their genetic similarity. Genotype combination G2P[4] was the most prevalent (34.6%), followed by G2P[8] (24.1%) and G1P[8] (21.1%). Given that several epitopes were conserved, neutralization motifs among circulating strains can be characterized as sufficiently matching vaccine strains Rotarix™ and RotaTeq™, but existing antigenic disparities should not be overlooked. The present results contribute to a better insight into the prevalence of rotavirus infection in our region and point out the need for epidemiological surveillance of rotaviruses before the introduction of vaccines. These data can help formulate future vaccine strategies in Serbia.

LTBP4, SPP1, and CD40 Variants: Genetic Modifiers of Duchenne Muscular Dystrophy Analyzed in Serbian Patients.

BACKGROUND: Clinical course variability in Duchenne muscular dystrophy (DMD) is partially explained by the mutation location in the DMD gene and variants in modifier genes. We assessed the effect of the SPP1, CD40, and LTBP4 genes and DMD mutation location on loss of ambulation (LoA). METHODS: SNPs in SPP1-rs28357094, LTBP4-rs2303729, rs1131620, rs1051303, rs10880, and CD40-rs1883832 were genotyped, and their effect was assessed by survival and hierarchical cluster analysis. RESULTS: Patients on glucocorticoid corticosteroid (GC) therapy experienced LoA one year later (p = 0.04). The modifying effect of SPP1 and CD40 variants, as well as LTBP4 haplotypes, was not observed using a log-rank test and multivariant Cox regression analysis. Cluster analysis revealed two subgroups with statistical trends in differences in age at LoA. Almost all patients in the cluster with later LoA had the protective IAAM LTBP4 haplotype and statistically significantly fewer CD40 genotypes with harmful T allele and "distal" DMD mutations. CONCLUSIONS: The modifying effect of SPP1, CD40, and LTBP4 was not replicated in Serbian patients, although our cohort was comparable in terms of its DMD mutation type distribution, SNP allele frequencies, and GC-positive effect with other European cohorts. Cluster analysis may be able to identify patient subgroups carrying a combination of the genetic variants that modify LoA.

Combination of Ascorbic Acid and Menadione Induces Cytotoxic Autophagy in Human Glioblastoma Cells.

We investigated the ability of the ascorbic acid (AA) and menadione (MD) combination, the well-known reactive oxidative species- (ROS-) generating system, to induce autophagy in human U251 glioblastoma cells. A combination of AA and MD (AA+MD), in contrast to single treatments, induced necrosis-like cell death mediated by mitochondrial membrane depolarization and extremely high oxidative stress. AA+MD, and to a lesser extent MD alone, prompted the appearance of autophagy markers such as autophagic vacuoles, autophagosome-associated LC3-II protein, degradation of p62, and increased expression of beclin-1. While both MD and AA+MD increased phosphorylation of AMP-activated protein kinase (AMPK), the well-known autophagy promotor, only the combined treatment affected its downstream targets, mechanistic target of rapamycin complex 1 (mTORC1), Unc 51-like kinase 1 (ULK1), and increased the expression of several autophagy-related genes. Antioxidant N-acetyl cysteine reduced both MD- and AA+MD-induced autophagy, as well as changes in AMPK/mTORC1/ULK1 activity and cell death triggered by the drug combination. Pharmacological and genetic autophagy silencing abolished the toxicity of AA+MD, while autophagy upregulation enhanced the toxicity of both AA+MD and MD. Therefore, by upregulating oxidative stress, inhibiting mTORC1, and activating ULK1, AA converts MD-induced AMPK-dependent autophagy from nontoxic to cytotoxic. These results suggest that AA+MD or MD treatment in combination with autophagy inducers could be further investigated as a novel approach for glioblastoma therapy.

High-throughput screening, next generation sequencing and machine learning: advanced methods in enzyme engineering.

Enzyme engineering is an important biotechnological process capable of generating tailored biocatalysts for applications in industrial chemical conversion and biopharma. Typical enhancements sought in enzyme engineering and in vitro evolution campaigns include improved folding stability, catalytic activity, and/or substrate specificity. Despite significant progress in recent years in the areas of high-throughput screening and DNA sequencing, our ability to explore the vast space of functional enzyme sequences remains severely limited. Here, we review the currently available suite of modern methods for enzyme engineering, with a focus on novel readout systems based on enzyme cascades, and new approaches to reaction compartmentalization including single-cell hydrogel encapsulation techniques to achieve a genotype-phenotype link. We further summarize systematic scanning mutagenesis approaches and their merger with deep mutational scanning and massively parallel next-generation DNA sequencing technologies to generate mutability landscapes. Finally, we discuss the implementation of machine learning models for computational prediction of enzyme phenotypic fitness from sequence. This broad overview of current state-of-the-art approaches for enzyme engineering and evolution will aid newcomers and experienced researchers alike in identifying the important challenges that should be addressed to move the field forward.

Graphene quantum dot antioxidant and proautophagic actions protect SH-SY5Y neuroblastoma cells from oxidative stress-mediated apoptotic death.

We investigated the ability of graphene quantum dot (GQD) nanoparticles to protect SH-SY5Y human neuroblastoma cells from oxidative/nitrosative stress induced by iron-nitrosyl complex sodium nitroprusside (SNP). GQD reduced SNP cytotoxicity by preventing mitochondrial depolarization, caspase-2 activation, and subsequent apoptotic death. Although GQD diminished the levels of nitric oxide (NO) in SNP-exposed cells, NO scavengers displayed only a slight protective effect, suggesting that NO quenching was not the main protective mechanism of GQD. GQD also reduced SNP-triggered increase in the intracellular levels of hydroxyl radical (•OH), superoxide anion (O2•-), and lipid peroxidation. Nonselective antioxidants, •OH scavenging, and iron chelators, but not superoxide dismutase, mimicked GQD cytoprotective activity, indicating that GQD protect cells by neutralizing •OH generated in the presence of SNP-released iron. Cellular internalization of GQD was required for optimal protection, since a removal of extracellular GQD by extensive washing only partly diminished their protective effect. Moreover, GQD cooperated with SNP to induce autophagy, as confirmed by the inhibition of autophagy-limiting Akt/PRAS40/mTOR signaling and increase in autophagy gene transcription, protein levels of proautophagic beclin-1 and LC3-II, formation of autophagic vesicles, and degradation of autophagic target p62. The antioxidant activity of GQD was not involved in autophagy induction, as antioxidants N-acetylcysteine and dimethyl sulfoxide failed to stimulate autophagy in SNP-exposed cells. Pharmacological inhibitors of early (wortmannin, 3-methyladenine) or late stages of autophagy (NH4Cl) efficiently reduced the protective effect of GQD. Therefore, the ability of GQD to prevent the in vitro neurotoxicity of SNP depends on both •OH/NO scavenging and induction of cytoprotective autophagy.

The prevalence of 30 HPV genotypes detected by EUROArray HPV in cervical samples among unvaccinated women from Vojvodina province, Serbia.

This study evaluates the pre-vaccination prevalence of HPV infection in women from Vojvodina, Serbia, according to age and cytological status. A total of 1,495 women, ranging from 18 to 65 years of age, with different cytological results were enrolled. The HPV genotyping assay was performed using the EUROArray HPV test in order to detect thirty genitally relevant HPV subtypes. In our study, the most prevalent genotypeswere HPV 16, 31, 51, and 53. Among these, HPV 16 was consistently present in all cytological subgroups. Twelve HPV genotypes classified as carcinogenic to humans (Group 1) were detected in 77.8.0% of HSIL/ASCH and 55.0% of NILM with abnormal colposcopy findings. Six possible carcinogens-HRs (group 2B) were often found in women with normal cytology (14.8%) and mild abnormalities (ASCUS and LSIL), but with lower frequence in HSIL/ASCH lesions (7.1%). HPVs 6 and 11(Group 3) were not found in the cases of HSIL/ASCH. Unclassified HPV types were equally distributed in all cytology groups: 20.7%, 19.1%, 16.3% and 13% of NILM, ASCUS, LSIL and HSIL/ASCH, respectively. Our findings highlight that majority of abnormal Pap test results are caused by Group 1 HPVs among women from our region. Low frequency HPVs of group 2A/2B, especially HSIL/ASCH, supports the conclusion that individual genotypes require consideration of each type as an individual agent. We expect a positive impact of HPV vaccine in reducing HPV-associated cervical lesions among women from Vojvodina province, after establishing vaccination programs in our country.

Sulfur dioxide and exacerbation of allergic respiratory diseases: A time-stratified case-crossover study.

BACKGROUND: Strong epidemiological evidence suggests that air pollution plays a significant role in the exacerbation of allergic respiratory diseases. This study aimed to assess the potential relationship between daily levels of sulfur dioxide (SO2) and emergency department (ED) visits for allergic diseases. MATERIALS AND METHODS: Data regarding ED visits for allergic respiratory diseases were routinely collected from the EDs in the Zlatibor district, and the General Hospital, Uzice. The daily average concentrations of SO2 were obtained from the regional automatic air quality monitoring stations. All data were collected from June 2012 to July 2014. A time-stratified case-crossover design was used. Crude odds ratios (ORs) and ORs adjusted for weather conditions were calculated using conditional logistic regression. RESULTS: Statistically significant associations were seen between 0-day lagged exposure to SO2 and ED visits for all allergic diseases (OR = 1.62; 95% confidence interval [CI]: 1.05-2.48; P = 0.028) and between 2-day lagged exposure to SO2 and ED visits for asthma with allergic rhinitis (OR = 2.00; 95% CI: 1.03-3.88; P = 0.042). These results were adjusted for temperature, temperature2, and humidity. CONCLUSION: Our results suggest that short-term exposure to SO2 conferred an increased risk of ED visits for allergic respiratory diseases, particularly for asthma with concomitant allergic rhinitis.

Short-term effects of air pollution on exacerbations of allergic asthma in Uzice region, Serbia.

INTRODUCTION: Many time-series studies have shown a positive association between air pollution and asthma exacerbation. However, till now only one study in Serbia has examined this relationship. AIM: To examine the associations between air pollution and asthma emergency department (ED) visits in the Uzice region, Serbia. MATERIAL AND METHODS: A time-stratified case-crossover design was applied to 424 ED visits for asthma exacerbation that occurred in the Uzice region, Serbia, in 2012-2014. Data about ED visits were routinely collected in the Uzice Health Centre. The daily average concentrations of particulate matter (PM2.5 and PM10), sulphur dioxide (SO2), nitrogen dioxide (NO2), and black carbon (BC) were measured by automatic ambient air quality monitoring stations. Odds ratios and their corresponding 95% confidence intervals were estimated using conditional logistic regression adjusted for the potential confounding influence of weather variables (temperature, humidity and air pressure). RESULTS: Statistically significant associations were observed between ED visits for asthma and 3-day lagged exposure to BC (OR = 3.23; 95% CI: 1.05-9.95), and between ED visits for asthma with coexisting allergic rhinitis and 0-day lag exposure to NO2 (OR = 1.57; 95% CI: 0.94-2.65), 2-day lag exposure to SO2 (OR = 1.97; 95% CI: 1.02-3.80), and 3-day lag exposure to PM10 (OR = 2.38; 95% CI: 1.17-4.84). CONCLUSIONS: Exposure to ambient air pollution in the Uzice region increases the risk of ED visits for asthma, particularly during the heating season.

AMP-activated protein kinase inhibits MPP+-induced oxidative stress and apoptotic death of SH-SY5Y cells through sequential stimulation of Akt and autophagy.

We investigated the interplay between the intracellular energy sensor AMP-activated protein kinase (AMPK), prosurvival kinase Akt, oxidative stress, and autophagy in the cytotoxicity of parkinsonian neurotoxin 1-methyl-4-phenyl piridinium (MPP+) towards SH-SY5Y human neuroblastoma cells. MPP+-mediated oxidative stress, mitochondrial depolarization, and apoptotic cell death were associated with rapid (within 2 h) activation of AMPK, its target Raptor, and prosurvival kinase Akt. Antioxidants N-acetylcysteine and butylated hydroxyanisole suppressed MPP+-induced cytotoxicity, AMPK, and Akt activation. A genetic or pharmacological inhibition of AMPK increased MPP+-triggered production of reactive oxygen species and cell death, and diminished Akt phosphorylation, while AMPK activation protected SH-SY5Y cells from MPP+. On the other hand, genetic or pharmacological inactivation of Akt stimulated MPP+-triggered oxidative stress and neurotoxicity, but did not affect AMPK activation. At later time-points (16-24 h), MPP+ inhibited the main autophagy repressor mammalian target of rapamycin, which coincided with the increase in the levels of autophagy marker microtubule-associated protein 1 light-chain 3B. MPP+ also increased the concentration of a selective autophagic target sequestosome-1/p62 and reduced the levels of lysosomal-associated membrane protein 1 and cytoplasmic acidification, suggesting that MPP+-induced autophagy was coupled with a decrease in autophagic flux. Nevertheless, further pharmacological inhibition of autophagy sensitized SH-SY5Y cells to MPP+-induced death. Antioxidants and AMPK knockdown reduced, whereas genetic inactivation of Akt potentiated neurotoxin-triggered autophagy. These results suggest that MPP+-induced oxidative stress stimulates AMPK, which protects SH-SY5Y cells through early activation of antioxidative Akt and late induction of cytoprotective autophagy.