Plasma Cytokeratin-18 Fragment Level Reflects the Metabolic Phenotype in Obesity.

There is growing interest in the non-invasive identification and monitoring of the outcome of liver damage in obese patients. Plasma cytokeratin-18 (CK-18) fragment levels correlate with the magnitude of hepatocyte apoptosis and have recently been proposed to independently predict the presence of non-alcoholic steatohepatitis (NASH). The aim of the study was to analyze the associations of CK-18 with obesity and related complications: insulin resistance, impaired lipid metabolism and the secretion of hepatokines, adipokines and pro-inflammatory cytokines. The study involved 151 overweight and obese patients (BMI 25-40), without diabetes, dyslipidemia or apparent liver disease. Liver function was assessed based on alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT) and the fatty liver index (FLI). CK-18 M30 plasma levels, FGF-21, FGF-19 and cytokines were determined by ELISA. CK-18 values >150 U/l were accompanied by high ALT, GGT and FLI, insulin resistance, postprandial hypertriglyceridemia, elevated FGF-21 and MCP-1 and decreased adiponectin. ALT activity was the strongest independent factor influencing high CK-18 plasma levels, even after an adjustment for age, sex and BMI [ß coefficient (95%CI): 0.40 (0.19-0.61)]. In conclusion, the applied CK-18 cut-off point at 150 U/l allows to distinguish between two metabolic phenotypes in obesity.

Omics biomarkers and an approach for their practical implementation to delineate health status for personalized nutrition strategies.

Personalized nutrition (PN) has gained much attention as a tool for empowerment of consumers to promote changes in dietary behavior, optimizing health status and preventing diet related diseases. Generalized implementation of PN faces different obstacles, one of the most relevant being metabolic characterization of the individual. Although omics technologies allow for assessment the dynamics of metabolism with unprecedented detail, its translatability as affordable and simple PN protocols is still difficult due to the complexity of metabolic regulation and to different technical and economical constrains. In this work, we propose a conceptual framework that considers the dysregulation of a few overarching processes, namely Carbohydrate metabolism, lipid metabolism, inflammation, oxidative stress and microbiota-derived metabolites, as the basis of the onset of several non-communicable diseases. These processes can be assessed and characterized by specific sets of proteomic, metabolomic and genetic markers that minimize operational constrains and maximize the information obtained at the individual level. Current machine learning and data analysis methodologies allow the development of algorithms to integrate omics and genetic markers. Reduction of dimensionality of variables facilitates the implementation of omics and genetic information in digital tools. This framework is exemplified by presenting the EU-Funded project PREVENTOMICS as a use case.

Glucose-Dependent Insulinotropic Polypeptide Plasma Level Influences the Effect of n-3 PUFA Supplementation.

Elevated glucose-dependent insulinotropic peptide (GIP) levels in obesity may predict the metabolic benefits of n-3 PUFA supplementation. This placebo-controlled trial aimed to analyze fasting and postprandial GIP response to 3-month n-3 PUFA supplementation (1.8 g/d; DHA:EPA, 5:1) along with caloric restriction (1200-1500 kcal/d) in obese subjects. Compliance was confirmed by the incorporation of DHA and EPA into red blood cells (RBCs). Blood analyses of glucose, insulin, non-esterified fatty acids (NEFAs), GIP and triglycerides were performed at fasting, and during an oral glucose tolerance test and a high fat mixed-meal tolerance test. Fatty acid composition of RBC was assessed by gas chromatography and total plasma fatty acid content and composition was measured by gas-liquid chromatography. The DHA and EPA content in RBCs significantly increased due to n-3 PUFA supplementation vs. placebo (77% vs. -3%, respectively). N-3 PUFA supplementation improved glucose tolerance and decreased circulating NEFA levels (0.750 vs. 0.615 mmol/L), as well as decreasing plasma saturated (1390 vs. 1001 µg/mL) and monounsaturated (1135 vs. 790 µg/mL) fatty acids in patients with relatively high GIP levels. The effects of n-3 PUFAs were associated with the normalization of fasting (47 vs. 36 pg/mL) and postprandial GIP levels. Obese patients with elevated endogenous GIP could be a target group for n-3 PUFA supplementation in order to achieve effects that obese patients without GIP disturbances can achieve with only caloric restriction.

The effect of bradykinin on the pro-inflammatory response of human adipocytes.

The proper functioning of adipose tissue is one of the factors in maintaining energy homeostasis. Adipocytes not only store lipids but also produce active molecules such as adipokines and adipocytokines, which are involved in many functions of adipose tissue, including the secretion of hormones that regulate energy and lipid metabolism. Inflammation has been shown to underlie the deregulation of adipose tissue function. Bradykinin belongs to a family of pro-inflammatory kinin peptides that are abundant in most tissues and biological fluids. This study aimed to determine the ability to produce kinin peptides and characterize the effect of bradykinin on pro-inflammatory responses in adipocytes. The Chub-S7 human preadipocyte line was differentiated to show specific properties for adipose tissue cells. The differentiated cells expressed genes that encode proteins such as kininogen, kallikrein, and prolylcarboxypeptidase that are involved in the production of kinins and also showed the expression of kinin receptors. The response of adipocytes to bradykinin was examined in relation to kinin concentration and the presence of kininase inhibitors. The high concentration of bradykinin induced a moderate increase in lipid accumulation, increased release of pro-inflammatory cytokines, and altered gene expression of molecules involved in adipocyte function, such as adiponectin, lipoprotein lipase, and other transcription factors. This study suggests an important role for kinin peptides in inducing inflammatory responses in adipocytes, which can modify the function of adipose tissue and ultimately lead to diseases related to disturbance of energy homeostasis. The results obtained may enrich our understanding of the mechanisms underlying obesity-related disorders.

The Effect of Caloric Restriction with and without n-3 PUFA Supplementation on Bone Turnover Markers in Blood of Subjects with Abdominal Obesity: A Randomized Placebo-Controlled Trial.

Weight loss contributes to an increased risk of hip fracture, especially in postmenopausal women. Omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation could diminish the adverse effect of weight loss on bone health. The aim of this randomized, placebo-controlled, double-blind parallel trial was to investigate the effect of caloric restriction and n-3 PUFA supplement intake on osteogenic markers (carboxylated osteocalcin (Gla-OC); procollagen I N-terminal propeptide (PINP)), as well as a bone resorption marker (C-terminal telopeptide of type I collagen (CTX-I)) in a serum of 64 middle aged individuals (BMI 25-40 kg/m2) with abdominal obesity. Bone remodeling, metabolic and inflammatory parameters and adipokines were determined before and after 3 months of an isocaloric diet (2300-2400 kcal/day) or a low-calorie diet (1200 kcal/day for women and 1500 kcal/day for men) along with n-3 PUFA (1.8 g/day) or placebo capsules. CTX-I and adiponectin concentrations were increased following 7% weight loss independently of supplement use. Changes in CTX-I were positively associated with changes in adiponectin level (rho = 0.25, p = 0.043). Thus, an increase in serum adiponectin caused by body weight loss could adversely affect bone health. N-3 PUFAs were without effect.

Epigenetic Regulation of Processes Related to High Level of Fibroblast Growth Factor 21 in Obese Subjects.

We hypothesised that epigenetics may play an important role in mediating fibroblast growth factor 21 (FGF21) resistance in obesity. We aimed to evaluate DNA methylation changes and miRNA pattern in obese subjects associated with high serum FGF21 levels. The study included 136 participants with BMI 27-45 kg/m2. Fasting FGF21, glucose, insulin, GIP, lipids, adipokines, miokines and cytokines were measured and compared in high serum FGF21 (n = 68) group to low FGF21 (n = 68) group. Human DNA Methylation Microarrays were analysed in leukocytes from each group (n = 16). Expression of miRNAs was evaluated using quantitative PCR-TLDA. The study identified differentially methylated genes in pathways related to glucose transport, insulin secretion and signalling, lipid transport and cellular metabolism, response to nutrient levels, thermogenesis, browning of adipose tissue and bone mineralisation. Additionally, it detected transcription factor genes regulating FGF21 and fibroblast growth factor receptor and vascular endothelial growth factor receptor pathways regulation. Increased expression of hsa-miR-875-5p and decreased expression of hsa-miR-133a-3p, hsa-miR-185-5p and hsa-miR-200c-3p were found in the group with high serum FGF21. These changes were associated with high FGF21, VEGF and low adiponectin serum levels. Our results point to a significant role of the epigenetic regulation of genes involved in metabolic pathways related to FGF21 action.

DNA methylation microarrays identify epigenetically regulated lipid related genes in obese patients with hypercholesterolemia.

BACKGROUND: Epigenetics can contribute to lipid disorders in obesity. The DNA methylation pattern can be the cause or consequence of high blood lipids. The aim of the study was to investigate the DNA methylation profile in peripheral leukocytes associated with elevated LDL-cholesterol level in overweight and obese individuals. METHODS: To identify the differentially methylated genes, genome-wide DNA methylation microarray analysis was performed in leukocytes of obese individuals with high LDL-cholesterol (LDL-CH, ≥ 3.4 mmol/L) versus control obese individuals with LDL-CH, < 3.4 mmol/L. Biochemical tests such as serum glucose, total cholesterol, HDL cholesterol, triglycerides, insulin, leptin, adiponectin, FGF19, FGF21, GIP and total plasma fatty acids content have been determined. Oral glucose and lipid tolerance tests were also performed. Human DNA Methylation Microarray (from Agilent Technologies) containing 27,627 probes for CpG islands was used for screening of DNA methylation status in 10 selected samples. Unpaired t-test and Mann-Whitney U-test were used for biochemical and anthropometric parameters statistics. For microarrays analysis, fold of change was calculated comparing hypercholesterolemic vs control group. The q-value threshold was calculated using moderated Student's t-test followed by Benjamini-Hochberg multiple test correction FDR. RESULTS: In this preliminary study we identified 190 lipid related CpG loci differentially methylated in hypercholesterolemic versus control individuals. Analysis of DNA methylation profiles revealed several loci engaged in plasma lipoprotein formation and metabolism, cholesterol efflux and reverse transport, triglycerides degradation and fatty acids transport and ß-oxidation. Hypermethylation of CpG loci located in promoters of genes regulating cholesterol metabolism: PCSK9, LRP1, ABCG1, ANGPTL4, SREBF1 and NR1H2 in hypercholesterolemic patients has been found. Novel epigenetically regulated CpG sites include ABCG4, ANGPTL4, AP2A2, AP2M1, AP2S1, CLTC, FGF19, FGF1R, HDLBP, LIPA, LMF1, LRP5, LSR, NR1H2 and ZDHHC8 genes. CONCLUSIONS: Our results indicate that obese individuals with hypercholesterolemia present specific DNA methylation profile in genes related to lipids transport and metabolism. Detailed knowledge of epigenetic regulation of genes, important for lipid disorders in obesity, underlies the possibility to influence target genes by changing diet and lifestyle, as DNA methylation is reversible and depends on environmental factors. These findings give rise for further studies on factors that targets methylation of revealed genes.

Enhanced GIP Secretion in Obesity Is Associated with Biochemical Alteration and miRNA Contribution to the Development of Liver Steatosis.

Nutrient excess enhances glucose-dependent insulinotropic polypeptide (GIP) secretion, which may in turn contribute to the development of liver steatosis. We hypothesized that elevated GIP levels in obesity may affect markers of liver injury through microRNAs. The study involved 128 subjects (body mass index (BMI) 25-40). Fasting and postprandial GIP, glucose, insulin, and lipids, as well as fasting alanine aminotransferase (ALT), γ-glutamyltransferase (GGT), cytokeratin-18, fibroblast growth factor (FGF)-19, and FGF-21 were determined. TaqMan low density array was used for quantitative analysis of blood microRNAs. Fasting GIP was associated with ALT [ß = 0.16 (confidence interval (CI): 0.01-0.32)], triglycerides [ß = 0.21 (95% CI: 0.06-0.36], and FGF-21 [ß = 0.20 (95%CI: 0.03-0.37)]; and postprandial GIP with GGT [ß = 0.17 (95%CI: 0.03-0.32)]. The odds ratio for elevated fatty liver index (>73%) was 2.42 (95%CI: 1.02-5.72) for high GIP versus low GIP patients. The miRNAs profile related to a high GIP plasma level included upregulated miR-136-5p, miR-320a, miR-483-5p, miR-520d-5p, miR-520b, miR-30e-3p, and miR-571. Analysis of the interactions of these microRNAs with gene expression pathways suggests their potential contribution to the regulation of the activity of genes associated with insulin resistance, fatty acids metabolism, and adipocytokines signaling. Exaggerated fasting and postprandial secretion of GIP in obesity are associated with elevated liver damage markers as well as FGF-21 plasma levels. Differentially expressed microRNAs suggest additional, epigenetic factors contributing to the gut-liver cross-talk.

Bradykinin and oxidative stress in patients with hereditary angioedema due to C1 inhibitor deficiency.

INTRODUCTION: Hereditary angioedema (HAE) is a rare autosomal dominant disease caused by genetic dysfunction of C1 inhibitor (C1-INH) due to mutations in the SERPING1 gene. The disorder is mediated mainly by bradykinin. The clinical course of the disease is varied and not related to genetic changes. OBJECTIVES: We aimed to evaluate redox homeostasis of peripheral blood mononuclear cells (PBMCs) in patients with HAE due to C1-INH deficiency (C1 INH HAE) by measuring the levels of reactive oxygen species (ROS) of PBMCs as well as plasma advanced glycation end products (AGEs) and advanced oxidation protein products (AOPPs). We also aimed to assess the effect of bradykinin on ROS levels. PATIENTS AND METHODS: We enrolled 30 adults with C1-INH-HAE and 15 healthy individuals. The levels of ROS were measured by flow cytometry, while the plasma levels of AGEs and AOPPs were determined spectrophotometrically by enzyme­ linked immunosorbent assays. RESULTS: Basal and hydrogen peroxide (H2O2)-induced ROS levels were higher in patients with HAE when compared with controls (P = 0.002 and P = 0.001, respectively), indicating abnormalities in redox homeostasis. Plasma AOPP and AGE levels were similar in both groups. Bradykinin reduced basal and H2O2-induced ROS generation in PBMCs only in patients with HAE (P = 0.03). CONCLUSIONS: The higher basal and H2O2-induced ROS levels in patients with C1 INH HAE indicate redox imbalance. However, by reducing basal and H2O2-induced ROS levels, bradykinin shows antioxidant action in this disorder.

Brain Metabolic Alterations in Rats Showing Depression-Like and Obesity Phenotypes.

Current data suggest an important role of brain metabolic disturbances in the pathogenesis of depression and obesity, diseases that frequently co-occur. Our aim was to determine whether there are changes in markers characterizing glucose metabolism in prenatal stress (PS; animal model of depression), in rats fed a high-fat diet (HFD), and especially in the model of depression and obesity co-occurrence. The changes in glucose-6-phosphate, glycogen, glucose transporters (GLUT1, GLUT4), glucagon-like peptide-1 receptor (GLP-1R), and mitochondrial complexes levels in the frontal cortex and/or hippocampus were observed. In the case of the coexistence of depression and obesity, the most important changes were (1) the decrease in the membrane form of GLUT4, which may suggest weaker insulin action in the frontal cortex, and (2) the diminished GLP-1R, which could cause neurodegenerative changes in the hippocampus. However, presented results suggested that HFD weakened the PS effect of uncoupling oxidative phosphorylation in the frontal cortex.

Effect of insulin resistance on whole blood mRNA and microRNA expression affecting bone turnover.

OBJECTIVE: To evaluate the effect of insulin resistance in obesity on the expression in whole blood of mRNA and miRNA affecting bone homeostasis as well as to estimate the influence of oral glucose load (OGTT) on serum osteocalcin concentration in obese individuals with and without insulin resistance. DESIGN: Cross-sectional study. METHODS: Carboxylated (cOC), undercarboxylated (ucOC) and total osteocalcin were measured by ELISA in the serum of obese subjects with insulin resistance (n = 41) and obese subjects without insulin resistance (n = 41) (control group) during OGTT. Analysis of gene expression (microarray) and miRNAs (real-time PCR) was performed in venous blood (representating samples) collected before OGTT from obese with insulin resistance and controls. RESULTS: Obese subjects with insulin resistance (higher HOMA-IR and lower oral glucose insulin sensitivity index) presented significantly increased expression of WNT signalling inhibitors (DKK1, DKK2, SOST, SFRP1) and downregulation of the key factor in WNT signalling - ß catenin participating in osteoblasts differentiation. Expression of miRNA involved in osteoblastogenesis was also inhibited (miR-29b, miR-181a, miR-210, miR-324-3p). During OGTT, contrary to the control group, subjects with insulin resistance presented suppression of cOC and total OC decrease after 1 and 2 h of oral glucose load. CONCLUSIONS: Obese subjects with insulin resistance may have defects in osteoblastogenesis that was demonstrated via key signalling molecules mRNA downregulation, and increased expression of WNT antagonists as well as inhibition of expression of miRNA participating in the regulation of osteoblast differentiation. Disturbed osteoblastogenesis in insulin-resistant subjects results in the suppression of blood carboxylated and total osteocalcin decrease during OGTT.

High Fat Mixed Meal Tolerance Test Leads to Suppression of Osteocalcin Decrease in Obese Insulin Resistant Subjects Compared to Healthy Adults.

Nutrients influence bone turnover. Carboxylated osteocalcin (Gla-OC) participates in bone formation whereas its undercarboxylated form (Glu-OC) acts as a hormone in glucose metabolism. The aim of the study was to determine the responses of Gla-OC, Glu-OC, and total-OC (calculated as the sum of Gla-OC and Glu-OC) to a high fat mixed meal tolerance test (HFMTT) in non-obese (body mass index (BMI) < 30 kg/m², n = 24) and obese subjects (30 < BMI < 40 kg/m², n = 70) (both sexes, aged 25⁻65 years). Serum Gla-OC and Glu-OC were measured at baseline as well as at 2 and 6 h during a HFMTT by enzyme-linked immunosorbent assay (ELISA). Baseline Gla-OC, Glu-OC, and total-OC levels were lower in obese individuals compared to non-obese participants (p = 0.037, p = 0.016 and p = 0.005, respectively). The decrease in Gla-OC and total-OC, but not in Glu-OC, concentrations during the HFMTT was suppressed in obese, but not in non-obese controls (p < 0.05, p < 0.01, p = 0.08, respectively). Subjects with the highest homeostatic model assessment for insulin resistance (HOMA-IR) index values had a less pronounced decrease in total-OC compared to patients with values of HOMA-IR index in the 1st quartile (p < 0.05). Net incremental area under Gla-OC inversely correlated with adiponectin (rho = -0.35, p = 0.001). Increase in insulin sensitivity and adiponectin level in obese subjects could beneficially influence postprandial bone turnover expressed by osteocalcin concentration.

Glucagon-like peptide-1 receptor agonist stimulates mitochondrial bioenergetics in human adipocytes.

Glucagon-like peptide 1 receptor agonists (GLP-1RAs) are relatively new pharmacological agents used to normalize glucose level in type 2 diabetes. Recently, GLP-1RAs have been approved for the treatment of obesity to reduce body weight in non-diabetic patients. The extra-pancre-atic effects of GLP-1RAs, as well as their molecular mechanism of action, are still poorly understood. Thus this study was aimed to verify the hypothesis that the mechanism of action of the GLP-1RAs involves mitochondria and that GLP-1RAs administration can improve mitochondrial functions. For this purpose, preadipocytes CHUBS7 were differentiated to mature adipocytes and then stimulated with GLP-1RA, exendin-4 at 100 nM for 24 h. Oxygen consumption rates, mitochondrial membrane potential, intracellular ATP (adenosine triphosphate) level, SIRT1 and SIRT3 gene expression and the histone deacetylases' activity were measured. Exendin-4 was found to uncouple mitochondrial electron transport from ATP synthesis, slightly decreasing mitochondrial membrane potential in mature adipocytes. Routine respiration and uncoupled oxy- gen consumption rates were higher in exendin-4 treated adipocytes than in the non-treated cells. The ATP level remained unchanged. Exendin-4 enhanced SIRT1 and SIRT3 genes expression. Histone deacetylases' activity in the nuclear fraction was not affected by exendin-4, although the activity of class III histone deacetylases was increased. All of the effects on mitochondrial bioenergetics induced by exendin-4 were abolished by addition of glucagon-like peptide 1 receptor antagonist. In conclusion, exendin-4 activates the sirtuin pathway and increases energy expenditure in human adipocytes. Our results suggest another mechanism that may be responsible for body weight reduction observed in patients using GLP-1RAs.

Relation of the protein glycation, oxidation and nitration to the osteocalcin level in obese subjects.

Carboxylated osteocalcin (Gla-OC) contributes to the bone formation, whereas its undercarboxylated form (Glu-OC) takes part in the energy metabolism. In vitro studies had shown that treatment of osteoblast-like cells with advanced glycation end product-modified bovine serum resulted in reduced synthesis of collagen 1 and osteocalcin. The aim of this study was to find association between Gla-OC and markers of protein glycation, oxidation and nitration, as well as pro-inflammatory and antioxidant defense markers in obese subjects. Non-obese [(body mass index (BMI)<30 kg/m; n=34)] and obese subjects (30

Similar effect of sodium nitroprusside and acetylsalicylic acid on antioxidant system improvement in mouse liver but not in the brain.

BACKGROUND: The aim of the present study was to analyze the relative antioxidant effects of acetylsalicylic acid (ASA) and sodium nitroprusside (SNP) in mouse liver and brain. METHODS: The activity of rhodanese, 3-mercaptopyruvate sulfurtransferase (MPST) and γ-cystathionase (CSE), functioning as antioxidant proteins and capable of producing H2S, was investigated in mouse liver and brain after intraperitoneal once a day administration of sodium nitroprusside (5 mg/kg body weight) or acetylsalicylic acid (500 mg/kg body weight) continued for 5 days. The tissues were homogenized and then the obtained supernatants were used for further determinations. At the same time, the levels of sulfane sulfur, reduced and oxidized glutathione, cysteine, cystine, and cystathionine were also studied in these tissues. RESULTS: Both ASA and SNP show a statistically significant increase of sulfurtransferases activities in liver. The mechanism of action of sodium nitroprusside appears to consist in liberation of nitric oxide (NO), an important signaling molecule in the mammalian body. SNP also releases cyanide ions, which are converted in the liver to thiocyanate by the enzyme rhodanese and/or MPST and/or γ-cystathionase - the activities of all the enzymes were elevated in reaction to SNP. The action of γ-cystathionase is dependent upon converting cystathionine to cysteine, a precursor of the major cellular antioxidant, glutathione. Under oxidizing conditions, an increase in cystathionine ß-synthase activity might indirectly result in an increase in the antioxidant glutathione level; this was reflected by the increased GSH/GSSG ratio in the liver, but not in the brain, where a trace activity of γ-cystathionase is normally detected. CONCLUSION: The results of the present investigations show that ASA and SNP may stimulate the GSH-dependent antioxidant system and protect liver cells from oxidative stress. An increased activity of the H2S-producing enzymes and the increased GSH/GSSG ratio may lead to an elevated level of H2S, a molecule with antioxidant properties. A similar effect was not observed in the brain. In case of both sodium nitroprusside and aspirin administration, homeostasis of sulfane sulfur level was noted in both the liver and brain.

Carboxylated and undercarboxylated osteocalcin in metabolic complications of human obesity and prediabetes.

BACKGROUND: Carboxylated osteocalcin (Gla-OC) participates in bone remodeling, whereas the undercarboxylated form (Glu-OC) takes part in energy metabolism. This study was undertaken to compare the blood levels of Glu-OC and Gla-OC in nonobese, healthy obese, and prediabetic volunteers and correlate it with the metabolic markers of insulin resistance and early markers of inflammation. METHODS: Nonobese (body mass index [BMI] <30 kg/m2 ; n = 34) and obese subjects (30

Effects of nanoporous anodic titanium oxide on human adipose derived stem cells.

The aim of current bone biomaterials research is to design implants that induce controlled, guided, successful, and rapid healing. Titanium implants are widely used in dental, orthopedic, and reconstructive surgery. A series of studies has indicated that cells can respond not only to the chemical properties of the biomaterial, but also, in particular, to the changes in surface topography. Nanoporous materials remain in focus of scientific queries due to their exclusive properties and broad applications. One such material is nanostructured titanium oxide with highly ordered, mutually perpendicular nanopores. Nanoporous anodic titanium dioxide (TiO2) films were fabricated by a three-step anodization process in propan-1,2,3-triol-based electrolyte containing fluoride ions. Adipose-derived stem cells offer many interesting opportunities for regenerative medicine. The important goal of tissue engineering is to direct stem cell differentiation into a desired cell lineage. The influence of nanoporous TiO2 with pore diameters of 80 and 108 nm on cell response, growth, viability, and ability to differentiate into osteoblastic lineage of human adipose-derived progenitors was explored. Cells were harvested from the subcutaneous abdominal fat tissue by a simple, minimally invasive, and inexpensive method. Our results indicate that anodic nanostructured TiO2 is a safe and nontoxic biomaterial. In vitro studies demonstrated that the nanotopography induced and enhanced osteodifferentiation of human adipose-derived stem cells from the abdominal subcutaneous fat tissue.

Dicarbonyl stress in clinical obesity.

The glyoxalase system in the cytoplasm of cells provides the primary defence against glycation by methylglyoxal catalysing its metabolism to D-lactate. Methylglyoxal is the precursor of the major quantitative advanced glycation endproducts in physiological systems - arginine-derived hydroimidazolones and deoxyguanosine-derived imidazopurinones. Glyoxalase 1 of the glyoxalase system was linked to anthropometric measurements of obesity in human subjects and to body weight in strains of mice. Recent conference reports described increased weight gain on high fat diet-fed mouse with lifelong deficiency of glyoxalase 1 deficiency, compared to wild-type controls, and decreased weight gain in glyoxalase 1-overexpressing transgenic mice, suggesting a functional role of glyoxalase 1 and dicarbonyl stress in obesity. Increased methylglyoxal, dicarbonyl stress, in white adipose tissue and liver may be a mediator of obesity and insulin resistance and thereby a risk factor for development of type 2 diabetes and non-alcoholic fatty liver disease. Increased methylglyoxal formation from glyceroneogenesis on adipose tissue and liver and decreased glyoxalase 1 activity in obesity likely drives dicarbonyl stress in white adipose tissue increasing the dicarbonyl proteome and related dysfunction. The clinical significance will likely emerge from on-going clinical evaluation of inducers of glyoxalase 1 expression in overweight and obese subjects. Increased transcapillary escape rate of albumin and increased total body interstitial fluid volume in obesity likely makes levels of glycation of plasma protein unreliable indicators of glycation status in obesity as there is a shift of albumin dwell time from plasma to interstitial fluid, which decreases overall glycation for a given glycemic exposure.

An In Vitro Study of the Neurotoxic Effects of N-Benzylpiperazine: A Designer Drug of Abuse.

Recently, the number of new psychoactive substances has significantly increased. Despite the systematic introduction of prohibition in trade of medicinal products which mimic the effects of illegal drugs, the problem concerning this group of drugs is still important although knowledge about the mechanism of action of those types of substances is scarce. This study aimed to follow the neurotoxic effect of N-benzylpiperazine (BZP), the central nervous system psychostimulant, using the human cancer LN-18 cell model. The statistically significant elevation of LDH levels, increased mitochondrial membrane potential, decreased ATP and increased ROS production, increased levels of DNA damage marker (8-OHdG) and activation of caspases: -3 and -9 confirmed by Real-Time PCR imply the activation of mitochondrial proapoptotic pathways induced by BZP after 24 h incubation. This study is a novel, preliminary attempt to explain the toxicity of one of the most popular designer drug of abuse at the cellular level.

Cannabinoids - a new weapon against cancer?

Cannabis has been cultivated by man since Neolithic times. It was used, among others for fiber and rope production, recreational purposes and as an excellent therapeutic agent. The isolation and characterization of the structure of one of the main active ingredients of cannabis - Δ9 - tetrahydrocannabinol as well the discovery of its cannabinoid binding receptors CB1 and CB2, has been a milestone in the study of the possibilities of the uses of Cannabis sativa and related products in modern medicine. Many scientific studies indicate the potential use of cannabinoids in the fight against cancer. Experiments carried out on cell lines in vitro and on animal models in vivo have shown that phytocannabinoids, endocannabinoids, synthetic cannabinoids and their analogues can lead to inhibition of the growth of many tumor types, exerting cytostatic and cytotoxic neoplastic effect on cells thereby negatively influencing neo-angiogenesis and the ability of cells to metastasize. The main molecular mechanism leading to inhibition of proliferation of cancer cells by cannabinoids is apoptosis. Studies have shown, however, that the process of apoptosis in cells, treated with recannabinoids, is a consequence of induction of endoplasmic reticulum stress and autophagy. On the other hand, in the cellular context and dosage dependence, cannabinoids may enhance the proliferation of tumor cells by suppressing the immune system or by activating mitogenic factors. Leading from this there is a an obvious need to further explore cannabinoid associated molecular pathways making it possible to develop safe therapeutic drug agents for patients in the future.