Stress changes amphetamine response, D2 receptor expression and epigenetic regulation in low-anxiety rats.

The aim of this study was to assess the influence of chronic restraint stress on amphetamine (AMPH)-related appetitive 50-kHz ultrasonic vocalisations (USVs) in rats differing in freezing duration in a contextual fear test (CFT), i.e. HR (high-anxiety responsive) and LR (low-anxiety responsive) rats. The LR and the HR rats, previously exposed to an AMPH binge experience, differed in sensitivity to AMPH's rewarding effects, measured as appetitive vocalisations. Moreover, chronic restraint stress attenuated AMPH-related appetitive vocalisations in the LR rats but had no influence on the HR rats' behaviour. To specify, the restraint LR rats vocalised appetitively less in the AMPH-associated context and after an AMPH challenge than the control LR rats. This phenomenon was associated with a decrease in the mRNA level for D2 dopamine receptor in the amygdala and its protein expression in the basal amygdala (BA) and opposite changes in the nucleus accumbens (NAc) - an increase in the mRNA level for D2 dopamine receptor and its protein expression in the NAc shell, compared to control conditions. Moreover, we observed that chronic restraint stress influenced epigenetic regulation in the LR and the HR rats differently. The contrasting changes were observed in the dentate gyrus (DG) of the hippocampus - the LR rats presented a decrease, but the HR rats showed an increase in H3K9 trimethylation. The restraint LR rats also showed higher miR-494 and miR-34c levels in the NAc than the control LR group. Our study provides behavioural and biochemical data concerning the role of differences in fear-conditioned response in stress vulnerability and AMPH-associated appetitive behaviour. The LR rats were less sensitive to the rewarding effects of AMPH when previously exposed to chronic stress that was accompanied by changes in D2 dopamine receptor expression and epigenetic regulation in mesolimbic areas.

Molecular foundations of chilling-tolerance of modern maize.

BACKGROUND: Recent progress in selective breeding of maize (Zea mays L.) towards adaptation to temperate climate has allowed the production of inbred lines withstanding cold springs with temperatures below 8 °C or even close to 0 °C, indicating that despite its tropical origins maize is not inherently cold-sensitive. RESULTS: Here we studied the acclimatory response of three maize inbred lines of contrasting cold-sensitivity selected basing on multi-year routine field data. The field observations were confirmed in the growth chamber. Under controlled conditions the damage to the photosynthetic apparatus due to severe cold treatment was the least in the cold-tolerant line provided that it had been subjected to prior moderate chilling, i.e., acclimation. The cold-sensitive lines performed equally poorly with or without acclimation. To uncover the molecular basis of the attained cold-acclimatability we performed comparative transcriptome profiling of the response of the lines to the cold during acclimation phase by means of microarrays with a statistical and bioinformatic data analysis. CONCLUSIONS: The analyses indicated three mechanisms likely responsible for the cold-tolerance: acclimation-dependent modification of the photosynthetic apparatus, cell wall properties, and developmental processes. Those conclusions supported the observed acclimation of photosynthesis to severe cold at moderate chilling and were further confirmed by experimentally showing specific modification of cell wall properties and repression of selected miRNA species, general regulators of development, in the cold-tolerant line subjected to cold stress.

Monitoring of dipeptidyl peptidase-IV (DPP-IV) activity in patients with mucopolysaccharidoses types I and II on enzyme replacement therapy - Results of a pilot study.

OBJECTIVES: Mucopolysaccharidoses (MPSs) are a group of rare, inherited metabolic disorders which result from the lack of one of the lysosomal enzymes responsible for the degradation of glycosaminoglycans. Early recognition of MPS is important as it enables prompt implementation of enzyme replacement therapy (ERT). Dipeptidyl peptidase-IV (DPP-IV) is a ubiquitous ectopeptidase which activity has been associated with the cell surface protein CD26. Our aims were to investigate plasma DPP-IV activity in untreated patients with MPS type II in comparison to control individuals and to evaluate changes of DPP-IV during ERT in MPS I or II patients. DESIGN AND METHODS: One MPS I and five MPS II patients were treated with ERT for up to 19 months. DPP-IV activity was measured in plasma with a colorimetric method using Gly-Pro-p-nitroanilide as a substrate. The reference intervals were observed in 17 healthy donors and in 9 MPS II individuals before ERT implementation. RESULTS: DPP-IV activity ranged from 557 to 1959 nmol/ml/h (median and interquartile range: 1453 [955­ 1554], n = 17) in plasma of control samples. In 9 untreated MPS II individuals, DPP-IV activity was higher and ranged from 2565 to 5968 nmol/ml/h (median and interquartile range: 4458 [4031­5161]). In 6 MPS patients receiving ERT, DPP-IV activity ranged from 2984 to 8628 nmol/ml/h. No declining tendency was observed during the treatment. CONCLUSIONS: DPP-IV activity is a good, newa nd valuable biomarker distinguishing between MPS and healthy individuals. However, it is not a useful marker of treatment efficacy and is unsuitable for monitoring.

Neutrophils as a Source of Chitinases and Chitinase-Like Proteins in Type 2 Diabetes.

PURPOSE: The pathophysiological role of human chitinases and chitinase-like proteins (CLPs) is not fully understood. We aimed to determine the levels of neutrophil-derived chitotriosidase (CHIT1), acidic mammalian chitinase (AMCase) and chitinase 3-like protein 1 (YKL-40) in patients with type 2 diabetes (T2D) and verify their association with metabolic and clinical conditions of these patients. METHODS: Neutrophils were obtained from the whole blood by gradient density centrifugation from 94 T2D patients and 40 control subjects. The activities of CHIT1 and AMCase as well as leukocyte elastase (LE) were measured fluorometrically and concentration of YKL-40 immunoenzymatically. Also, routine laboratory parameters in serum/plasma were determined by standard methods. RESULTS: The levels of all three examined proteins were about 2-times higher in diabetic patients in comparison to control subjects. They were significantly correlated with the activity of LE and increased progressively across tertiles of LE activity. Moreover, the activities of CHIT1 and AMCase were significantly correlated with each other. Metabolic compensation of diabetes did not influence the levels of these proteins. In the subgroup of patients with inflammatory evidence only YKL-40 concentration was significantly higher compared to those without inflammation. The highest levels of all three proteins were observed in patients with macroangiopathies. Insulin therapy was associated with lower levels of examined proteins. CONCLUSIONS: We revealed that neutrophils may be an important source of the increased levels of chitinases and CLPs in T2D, and these proteins may participate in inflammatory mechanisms in the course of the disease and consequent development of diabetic angiopathies.

Proteins from the 18 glycosyl hydrolase family are associated with kidney dysfunction in patients with diabetes type 2.

OBJECTIVES: To investigate chitotriosidase (CHIT1) activity and chitinase-3-like protein 1 (YKL-40) concentration in plasma of type 2 diabetic patients and evaluate their relationship with kidney dysfunction. MATERIALS AND METHODS: 94 diabetic subjects and 33 controls were enrolled in the study. Plasma CHIT1 activity and YKL-40 concentration were measured along with routine laboratory parameters. RESULTS: Levels of CHIT1 and YKL-40 in plasma of type 2 diabetic patients increased progressively with the degree of albuminuria. CHIT1 discriminated normoalbuminuric subjects from those with abnormal albuminuria better than YKL-40. CONCLUSIONS: CHIT1represent a supportive biomarker connected with development of diabetic vascular complications, especially kidney dysfunction.