Utjecaj kroničnoga stresa i starenja na lipidne splavi moždanih stanica u štakora [Influence of chronic stress and aging on lipid rafts in rat brain cells]

The main hypothesis of this thesis proposed that aging and stress combined lead towards changes in lipid rafts composition of brain and trigger neurodegeneration mediated by location shift of lipid raft proteins in hippocampus – insulin and leptin receptor. In experiments performed in this thesis diminished memory in older females was observed and was followed by reduced expression of insulin and AMPA receptors in hippocampus of older animals. Leptin receptor was activated upon stress in older animals and could be a potential neuroprotection activator. Also, it was determined that both – insulin and leptin receptors are not located inside lipid rafts of hippocampus and cerebellum as considered up to now by peripheral tissue analysis. Lipid content changes of lipid rafts upon stress were noticed as GM1 ganglioside expression increase in CA1 and dentate gyrus of hippocampus of young animals and increase of GD1a expression in CA1 region of hippocampus in all chronically stressed animal groups. Also, colocalization of amyloid precursor protein and GD1a was observed in hippocampus of older females as a result of chronic stress response. If insulin and leptin receptors expression is decreased, AMPA receptor and neuroplastin follow this trend. It implies a connection of leptin and insulin signalling pathways with pathways involved with neuroplasticity. During experimental part of this thesis, a unique animal model of sex and age specific chronic stress was developed that implies strong chronic stress resistance of young animals. It was observed that chronic stress had the strongest impact in older females and that stress regulation in the brain is sex and age specific

Edukacija o primjeni Pravilnika za opis i pristup građi u knjižnicama arhivima i muzejima kroz Centar za stalno stručno usavršavanje knjižničara u Republici Hrvatskoj i Radnu grupu za edukaciju pri Stalnom odboru za razvoj i održavanje pravilnika

Cilj. Cilj je rada analizirati sudjelovanje i zadovoljstvo edukacijama za primjenu Pravilnika KAM koje su se održavale od 2018. do 2022. godine u okviru Centra za stalno stručno usavršavanje knjižničara u Republici Hrvatskoj (CSSU). Usto rad donosi analizu posjećenosti regionalnih radionica (održanih neovisno o CSSU-u) na temu primjene Pravilnika KAM u organizaciji Radne grupe za edukaciju pri Stalnom odboru za razvoj i održavanje Pravilnika KAM u suradnji sa županijskim matičnim narodnim knjižnicama i Vijećem za matičnu djelatnost Muzejskog dokumentacijskog centra (MDC). Pristup/metodologija/dizajn. U radu se analiziraju podaci o edukacijama za primjenu Pravilnika KAM: teme, formati, trajanje edukacija, broj polaznika te rezultati evaluacijskih upitnika – zadovoljstvo polaznika edukacijskim sadržajima i predavačima te primjenjivost na radno mjesto. Rezultati. Na edukacijama o Pravilniku KAM tijekom petogodišnjeg razdoblja sudjelovalo je najviše knjižničara, ali i značajan broj polaznika iz arhiva i muzeja. Održavanjem edukacija online te javnom dostupnošću snimki webinara od 2020. godine omogućena je široka dostupnost edukativnog sadržaja. Polaznici su iskazali izvrsnu razinu zadovoljstva kvalitetom predavača i edukacijskih sadržaja te vrlo dobru razinu zadovoljstva primjenjivošću edukacija na radno mjesto. Održavanjem regionalnih radionica praktična primjena Pravilnika KAM približena je široj stručnoj zajednici. Ograničenja. Od 2018. do 2020. godine za polaznike iz arhiva i muzeja prilikom prijave nije bila ponuđena opcija odabira navedenih ustanova te je za njih bila predviđena kategorija „Ostalo”. Međutim naknadnom analizom utvrđeno je da se jedan broj takvih polaznika (na temelju samostalnog upisa) nalazi i u kategoriji „Specijalne knjižnice“. Stoga su ti polaznici, za potrebe ovog rada, naknadno izdvojeni u zasebne kategorije prema vrsti ustanove iz koje dolaze. Praktična primjena. Rezultati rada uzet će se u obzir pri planiranju edukacija CSSU-a u kontekstu bibliografske kontrole i katalogizacije građe te općenito novih edukacijskih aktivnosti za primjenu Pravilnika KAM. Originalnost/vrijednost. U radu su prikazani trendovi u području stručnog usavršavanja stručnjaka iz knjižnica, arhiva i muzeja o primjeni Pravilnika KAM

Ovariectomy and chronic stress lead toward leptin resistance in the satiety centers and insulin resistance in the hippocampus of Sprague- Dawley rats

Aim To evaluate the changes in the expression level of gonadal steroid, insulin, and leptin receptors in the brain of adult Sprague-Dawley female rats due to ovariectomy and/or chronic stress. Methods Sixteen-week-old ovariectomized and non-ovariectomized female Sprague-Dawley rats were divided in two groups and exposed to three 10-day-sessions of sham or chronic stress. After the last stress-session the brains were collected and free-floating immunohistochemical staining was performed using androgen (AR), progesterone (PR), estrogen-β (ER-β), insulin (IR-α), and leptin receptor (ObR) antibodies. The level of receptors expression was analyzed in hypothalamic (HTH), cortical (CTX), dopaminergic (VTA/SNC), and hippocampal regions (HIPP). Results Ovariectomy downregulated AR in the hypothalamic satiety centers and hippocampus. It prevented or attenuated the stress-specific upregulation of AR in these regions. The main difference in stress response between non-ovariectomized and ovariectomized females was in PR level. Ovariectomized ones had increased PR level in the HTH, VTA, and HIPP. Combination of stressors pushed the hypothalamic satiety centers toward the rise of ObR and susceptibility to leptin resistance. When exposed to combined stressors, the HIPP, SNC and piriform cortex upregulated the expression of IR-α and the possibility to develop insulin resistance. Conclusion Ovariectomy exacerbates the effect of chronic stress by preventing gonadal receptor-specific stress response reflected in the up-regulation of AR in the satiety and hippocampal regions, while stress after ovariectomy usually raises PR. The final outcome of inadequate stress response is reflected in the upregulation of ObR in the satiety centers and IR-α in the regions susceptible to early neurodegeneration. We discussed the possibility of stress induced metabolic changes under conditions of hormone deprivatio

Plasma Content of Glucose, C-reactive Protein, Uric Acid and Cholesterol in Male, Female and Ovariectomized Rats upon Acute and Chronic Stress – a Path for Development of Cardiovascular Diseases

To explore sex differences in cardiovascular function under stress, we analyzed plasma levels of glucose, C-reactive protein (CRP), uric acid and cholesterol in male, female and ovariectomized rats under acute and chronic stress. Glucose tolerance test (GTT) was performed in all rats before any stress was performed, as well as later in the chronic stress experiment. GTT in control animals showed the same trend as in chronically stressed. Male rats showed the highest plasma level of glucose and uric acid upon acute stress in comparison between the other two groups. Ovariectomized rats reached the highest concentration of plasma cholesterol during acute and chronic stress, respectively and also the highest plasma concentration of CRP during acute stress. Stress, as a risk factor of metabolic syndrome, affected biochemical parameters in males upon acute more than upon chronic stress, but the opposite was observed in female rats. Gender differences supported by ovariectomy show that stress managing could be affected by sexual hormones

Sex differences in oxidative stress level and antioxidative enzymes expression and activity in obese pre-diabetic elderly rats treated with metformin or liraglutide

Aim To determine the effects of metformin or liraglutide on oxidative stress level and antioxidative enzymes gene ex - pression and activity in the blood and vessels of pre-diabet - ic obese elderly Sprague-Dawley (SD) rats of both sexes. Methods Male and female SD rats were assigned to the following groups: a) control group (fed with standard ro - dent chow); b) high-fat and high-carbohydrate diet (HSHFD) group fed with HSHFD from 20-65 weeks of age; c) HSHFD+metformin treatment (50 mg/kg/d s.c.); and d) HSHFD+liraglutide treatment (0.3 mg/kg/d s.c). Oxidative stress parameters (ferric reducing ability of plasma and thiobarbituric acid reactive substances) and superoxide dis - mutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity and gene expression were determined from serum, aortas, and surface brain blood vessels (BBV). Results HSHFD increased body weight in both sexes com - pared with the control group, while liraglutide prevented this increase. Blood glucose level did not change. The lira - glutide group had a significantly increased antioxidative ca - pacity compared with the HSHFD group in both sexes. The changes in antioxidative enzymes’ activities in plasma were more pronounced in male groups. The changes in gene ex - pression of antioxidative enzymes were more prominent in microvessels and may be attributed to weight gain preven - tion. Conclusions Obesity and antidiabetic drugs caused sexrelated differences in the level of antioxidative parameters. Liraglutide exhibited stronger antioxidative effects than metformin. These results indicate that weight gain due to HSHFD is crucial for developing oxidative stress and for in - hibiting antioxidative protective mechanism

Sex-specific chronic stress response at the level of adrenal gland modified sexual hormone and leptin receptors

Aim To compare cardiometabolic risk-related biochemical markers and sexual hormone and leptin receptors in the adrenal gland of rat males, non-ovariectomized females (NON-OVX), and ovariectomized females (OVX) under chronic stress. Methods Forty six 16-week-old Sprague-Dawley rats were divided into male, NON-OVX, and OVX group and exposed to chronic stress or kept as controls. Weight, glucose tolerance test (GTT), serum concentration of glucose, and cholesterol were measured. Adrenal glands were collected at the age of 28 weeks and immunohistochemical staining against estrogen beta (ERβ), progesterone (PR), testosterone (AR), and leptin (Ob-R) receptors was performed. Results Body weight, GTT, serum cholesterol, and glucose changed in response to stress as expected and validated the applied stress protocol. Stressed males had significantly higher number of ERβ receptors in comparison to control group (P = 0.028). Stressed NON-OVX group had significantly decreased AR in comparison to control group (P = 0.007). The levels of PR did not change in any consistent pattern. The levels of Ob-R increased upon stress in all groups, but the significant difference was reached only in the case of stressed OVX group compared to control (P = 0.033). Conclusion Chronic stress response was sex specific. OVX females had similar biochemical parameters as males. Changes upon chronic stress in adrenal gland were related to an increase in testosterone receptor in females and decrease in estrogen receptor in males

Single acute stress-induced progesterone and ovariectomy alter cardiomyocyte contractile function in female rats

Aim To assess how ovarian-derived sex hormones (in particular progesterone) modify the effects of single acute stress on the mechanical and biochemical properties of left ventricular cardiomyocytes in the rat. Methods Non-ovariectomized (control, n = 8) and ovariectomized (OVX, n = 8) female rats were kept under normal conditions or were exposed to stress (control-S, n = 8 and OVX-S, n = 8). Serum progesterone levels were measured using a chemiluminescent immunoassay. Left ventricular myocardial samples were used for isometric force measurements and protein analysis. Ca2+-dependent active force (Factive), Ca2+-independent passive force (Fpassive), and Ca2+-sensitivity of force production were determined in single, mechanically isolated, permeabilized cardiomyocytes. Stress- and ovariectomy-induced alterations in myofilament proteins (myosin-binding protein C [MyBP-C], troponin I [TnI], and titin) were analyzed by sodium dodecyl sulfate gel electrophoresis using protein and phosphoprotein stainings. Results Serum progesterone levels were significantly increased in stressed rats (control-S, 35.6 ± 4.8 ng/mL and OVX-S, 21.9 ± 4.0 ng/mL) compared to control (10 ± 2.9 ng/mL) and OVX (2.8 ± 0.5 ng/mL) groups. Factive was higher in the OVX groups (OVX, 25.9 ± 3.4 kN/m2 and OVX-S, 26.3 ± 3.0 kN/m2) than in control groups (control, 16.4 ± 1.2 kN/m2 and control-S, 14.4 ± 0.9 kN/m2). Regarding the potential molecular mechanisms, Factive correlated with MyBP-C phosphorylation, while myofilament Ca2+-sensitivity inversely correlated with serum progesterone levels when the mean values were plotted for all animal groups. Fpassive was unaffected by any treatment. Conclusion Stress increases ovary-independent synthesis and release of progesterone, which may regulate Ca2+-sensitivity of force production in left ventricular cardiomyocytes. Stress and female hormones differently alter Ca2+- dependent cardiomyocyte contractile force production, which may have pathophysiological importance during stress conditions affecting postmenopausal women

Standardization procedure for flow cytometry data harmonization in prospective multicenter studies

One of the most challenging objective for clinical cytometry in prospective multicenter immunomonitoring trials is to compare frequencies, absolute numbers of leukocyte populations and further the mean fluorescence intensities of cell markers, especially when the data are generated from different instruments. Here, we describe an innovative standardization workflow to compare all data to carry out any large-scale, prospective multicentric flow cytometry analysis whatever the duration, the number or type of instruments required for the realization of such project

Machine learning identifies a common signature for anti-SSA/Ro60 antibody expression across autoimmune diseases

Anti-Ro autoantibodies are among the most frequently detected extractable nuclear antigen autoantibodies, mainly associated with primary Sjögren's syndrome (pSS), systemic lupus erythematosus (SLE) and undifferentiated connective tissue disease (UCTD). Is there a common signature to all patients expressing anti-Ro60 autoantibodies regardless of their disease phenotype?Using high-throughput multi-omics data collected within the cross-sectional cohort from the PRECISESADS IMI project (genetic, epigenomic, transcriptomic, combined with flow cytometric data, multiplexed cytokines, classical serology and clinical data), we assessed by machine learning the integrated molecular profiling of 520 anti-Ro60-positive (anti-Ro60+ ) compared to 511 anti-Ro60-negative (anti-Ro60- ) patients with pSS, SLE and UCTD, and 279 healthy controls (HCs).The selected features for RNA-Seq, DNA methylation and GWAS data allowed a clear separation between anti-Ro60+ and anti-Ro60- patients. The different features selected by machine learning from the anti-Ro60+ patients constitute specific signatures when compared to anti-Ro60- patients and HCs. Remarkably, the transcript z-score of three genes (ATP10A, MX1 and PARP14), presenting an overexpression associated with a hypomethylation and genetic variation, and independently identified by the Boruta algorithm, was clearly higher in anti-Ro60+ patients compared to anti-Ro60- patients in all the diseases. We demonstrate that these signatures, enriched in interferon stimulated genes, were also found in anti-Ro60+ patients with rheumatoid arthritis and systemic sclerosis and remained stable over time and not influenced by treatment.Anti-Ro60+ patients present a specific inflammatory signature regardless of their disease suggesting that a dual therapeutic approach targeting both Ro-associated RNAs and anti-Ro60 autoantibodies should be considered