Stingless bee honey protects against lipopolysaccharide induced-chronic subclinical systemic inflammation and oxidative stress by modulating Nrf2, NF-κB and p38 MAPK

Background: Epidemiological and experimental studies have extensively indicated that chronic subclinical systemic inflammation (CSSI) and oxidative stress are risk factors for several chronic diseases, including cancer, arthritis, type 2 diabetes, and cardiovascular and neurodegenerative diseases. This study examined the protective effect of stingless bee honey (SBH) supplementation against lipopolysaccharide (LPS)-induced CSSI, pointing to the possible involvement of NF-κB, p38 MAPK and Nrf2 signaling. Methods: CSSI was induced in male Sprague Dawley rats by intraperitoneal injection of LPS three times per week for 28 days, and SBH (4.6 and 9.3 g/kg/day) was supplemented for 30 days. Results: LPS-induced rats showed significant leukocytosis, and elevated serum levels of CRP, TNF-α, IL-1β, IL-6, IL-8, MCP-1, malondialdehyde (MDA) and 8-hydroxy-2′-deoxyguanosine (8-OHdG), accompanied with diminished antioxidants. Treatment with SBH significantly ameliorated inflammatory markers, MDA and 8-OHdG, and enhanced antioxidants in LPS-induced rats. In addition, SBH decreased NF-κB p65 and p38 MAPK, and increased Nrf2 expression in the liver, kidney, heart and lung of LPS-induced rats. Furthermore, SBH prevented LPS-induced histological and functional alterations in the liver, kidney, heart and lung of rats. Conclusion: SBH has a substantial protective role against LPS-induced CSSI in rats mediated via amelioration of inflammation, oxidative stress and NF-κB, p38 MAPK and Nrf2 signaling

Molecular cytogenetic diagnostics of structural chromosomal aberrations with FISCH method

Department of Medical Chemistry and Clinical BiochemistryÚstav lékařské chemie a klinické biochemieSecond Faculty of Medicine2. lékařská fakult

Molecular cytogenetic analysis of mosaic chromosomal abnormalities

The focus of this diploma thesis is on mosaic numerical and structural chromosomal aberrations. In its theoretical part, general problems of mosaicism, its phenotypic effect, mechanisms of origin, related epigenetic modifications, and diagnostic options are described. The methodical part of the thesis then primarily refers to fluorescence in situ hybridization (FISH) and its application in the diagnostics of mosaicism. This method was used in the examination of 29 patients with numerical as well as structural abnormalities of autosomes or gonosomes with proven or suspected mosaicism. On the basis of this analysis, possible errors of measurement were determined and data for statistic evaluation were retrieved. For the examinations of three patients an alternative of the comparative genomic hybridization, the array CGH technique, was applied. The FISH method, although being based on random selection and human factor, proved sufficient sensitivity as well as specificity in the field of low-frequency mosaicism diagnostics. The main critical factors responsible for potential misinterpretation of the data arose from inherent characteristics of the biological material, incorrect targeting of the analysis, probe instability, bleed through effect and absence of mitosis during the structural aberrations analysis

Regulatory mechanisms affecting etiopathogenesis of obesity, insulin resistance and type 2 diabetes mellitus.

Subclinical inflammation plays a pivotal role in the development of obesity- related complications including type 2 diabetes mellitus, hypertension and cardiovascular diseases. Macrophages are considered important players participating in the initiation and progression of subclinical inflammation within as well as outside of adipose tissue. The first part of this dissertation thesis was focused on macrophage characterization and their quantitative and qualitative changes accompanying metabolic improvements after bariatric surgery. We have demonstrated that the number of macrophages in subcutaneous adipose tissue is reduced regardless of their M1 or M2 polarization manifested as positivity of both the M1- associated CD40 antigen and the M2-associated CD163 and CD206 antigens 6 months after bariatric surgery. Thus, as suggested by previously published data, subcutaneous adipose tissue macrophages seem to have a mixed phenotype. We further confirmed a higher number of non- classical monocytes, which play a role in the control of vascular integrity, in obese subjects as well as a classical monocyte-derived origin of CD163 positive monocytes. Our data also support the previous suggestion of the soluble form of CD163 antigen being a suitable marker of metabolic complications of obesity. The second part..

Molecular cytogenetic diagnostics of structural chromosomal aberrations with FISCH method

Department of Medical Chemistry and Clinical BiochemistryÚstav lékařské chemie a klinické biochemieSecond Faculty of Medicine2. lékařská fakult

Dendritic Cells in Subcutaneous and Epicardial Adipose Tissue of Subjects with Type 2 Diabetes, Obesity, and Coronary Artery Disease

Dendritic cells (DCs) are professional antigen-presenting cells contributing to regulation of lymphocyte immune response. DCs are divided into two subtypes: CD11c-positive conventional or myeloid (cDCs) and CD123-positive plasmacytoid (pDCs) DCs. The aim of the study was to assess DCs (HLA-DR+ lineage-) and their subtypes by flow cytometry in peripheral blood and subcutaneous (SAT) and epicardial (EAT) adipose tissue in subjects with (T2DM, n=12) and without (non-T2DM, n=17) type 2 diabetes mellitus undergoing elective cardiac surgery. Subjects with T2DM had higher fasting glycemia (8.6±0.7 vs. 5.8±0.2 mmol/l, p<0.001) and glycated hemoglobin (52.0±3.4 vs. 36.9±1.0 mmol/mol, p<0.001) and tended to have more pronounced inflammation (hsCRP: 9.8±3.1 vs. 5.1±1.9 mg/ml, p=0.177) compared with subjects without T2DM. T2DM was associated with reduced total DCs in SAT (1.57±0.65 vs. 4.45±1.56% for T2DM vs. non-T2DM, p=0.041) with a similar, albeit insignificant, trend in EAT (0.996±0.33 vs. 2.46±0.78% for T2DM vs. non-T2DM, p=0.171). When analyzing DC subsets, no difference in cDCs was seen between any of the studied groups or adipose tissue pools. In contrast, pDCs were increased in both SAT (13.5±2.0 vs. 4.6±1.9% of DC cells, p=0.005) and EAT (29.1±8.7 vs. 8.4±2.4% of DC, p=0.045) of T2DM relative to non-T2DM subjects as well as in EAT of the T2DM group compared with corresponding SAT (29.1±8.7 vs. 13.5±2.0% of DC, p=0.020). Neither obesity nor coronary artery disease (CAD) significantly influenced the number of total, cDC, or pDC in SAT or EAT according to multiple regression analysis. In summary, T2DM decreased the amount of total dendritic cells in subcutaneous adipose tissue and increased plasmacytoid dendritic cells in subcutaneous and even more in epicardial adipose tissue. These findings suggest a potential role of pDCs in the development of T2DM-associated adipose tissue low-grade inflammation

Different Expression of Mitochondrial and Endoplasmic Reticulum Stress Genes in Epicardial Adipose Tissue Depends on Coronary Atherosclerosis

The aim of our study was to analyze mitochondrial and endoplasmic reticulum (ER) gene expression profiles in subcutaneous (SAT) and epicardial (EAT) adipose tissue, skeletal muscle, and myocardium in patients with and without CAD undergoing elective cardiac surgery. Thirty-eight patients, 27 with (CAD group) and 11 without CAD (noCAD group), undergoing coronary artery bypass grafting and/or valvular surgery were included in the study. EAT, SAT, intercostal skeletal muscle, and right atrium tissue and blood samples were collected at the start and end of surgery; mRNA expression of selected mitochondrial and ER stress genes was assessed using qRT-PCR. The presence of CAD was associated with decreased mRNA expression of most of the investigated mitochondrial respiratory chain genes in EAT, while no such changes were seen in SAT or other tissues. In contrast, the expression of ER stress genes did not differ between the CAD and noCAD groups in almost any tissue. Cardiac surgery further augmented mitochondrial dysfunction in EAT. In our study, CAD was associated with decreased expression of mitochondrial, but not endoplasmic reticulum stress genes in EAT. These changes may contribute to the acceleration of coronary atherosclerosis

Coronary Artery Disease Is Associated with an Increased Amount of T Lymphocytes in Human Epicardial Adipose Tissue

Immunocompetent cells including lymphocytes play a key role in the development of adipose tissue inflammation and obesity-related cardiovascular complications. The aim of the study was to explore the relationship between epicardial adipose tissue lymphocytes and coronary artery disease (CAD). To this end, we studied the content and phenotype of lymphocytes in peripheral blood, subcutaneous adipose tissue (SAT), and epicardial adipose tissue (EAT) in subjects with and without CAD undergoing elective cardiac surgery. Eleven subjects without CAD (non-CAD group) and 22 age-, BMI-, and HbA1C-matched individuals with CAD were included into the study. Blood, SAT, and EAT samples were obtained at the beginning of surgery. Lymphocyte populations were quantified as % of CD45+ cells using flow cytometry. Subjects with CAD had a higher total lymphocyte amount in EAT compared with SAT (32.24±7.45 vs. 11.22±1.34%, p=0.025) with a similar trend observed in non-CAD subjects (29.68±7.61 vs. 10.13±2.01%, p=0.067). T (CD3+) cells were increased (75.33±2.18 vs. 65.24±4.49%, p=0.032) and CD3- cells decreased (21.17±2.26 vs. 31.64±4.40%, p=0.028) in EAT of CAD relative to the non-CAD group. In both groups, EAT showed an elevated percentage of B cells (5.22±2.43 vs. 0.96±0.21%, p=0.039 for CAD and 12.49±5.83 vs. 1.16±0.19%, p=0.016 for non-CAD) and reduced natural killer (NK) cells (5.96±1.32 vs. 13.22±2.10%, p=0.012 for CAD and 5.32±1.97 vs. 13.81±2.72%, p=0.022 for non-CAD) relative to SAT. In conclusion, epicardial adipose tissue in subjects with CAD shows an increased amount of T lymphocytes relative to non-CAD individuals as well as a higher number of total and B lymphocytes and reduced NK cells as compared with corresponding SAT. These changes could contribute to the development of local inflammation and coronary atherosclerosis