Diet changes alter paternally inherited epigenetic pattern in male Wild guinea pigs.

Epigenetic modifications, of which DNA methylation is the most stable, are a mechanism conveying environmental information to subsequent generations via parental germ lines. The paternal contribution to adaptive processes in the offspring might be crucial, but has been widely neglected in comparison to the maternal one. To address the paternal impact on the offspring's adaptability to changes in diet composition, we investigated if low protein diet (LPD) in F0 males caused epigenetic alterations in their subsequently sired sons. We therefore fed F0 male Wild guinea pigs with a diet lowered in protein content (LPD) and investigated DNA methylation in sons sired before and after their father's LPD treatment in both, liver and testis tissues. Our results point to a 'heritable epigenetic response' of the sons to the fathers' dietary change. Because we detected methylation changes also in the testis tissue, they are likely to be transmitted to the F2 generation. Gene-network analyses of differentially methylated genes in liver identified main metabolic pathways indicating a metabolic reprogramming ('metabolic shift'). Epigenetic mechanisms, allowing an immediate and inherited adaptation may thus be important for the survival of species in the context of a persistently changing environment, such as climate change.

Periplasmic Screening for Artificial Metalloenzymes.

Artificial metalloenzymes represent an attractive means of combining state-of-the-art transition metal catalysis with the benefits of natural enzymes. Despite the tremendous recent progress in this field, current efforts toward the directed evolution of these hybrid biocatalysts mainly rely on the laborious, individual purification of protein variants rendering the throughput, and hence the outcome of these campaigns feeble. We have recently developed a screening platform for the directed evolution of artificial metalloenzymes based on the streptavidin-biotin technology in the periplasm of the Gram-negative bacterium Escherichia coli. This periplasmic compartmentalization strategy comprises a number of compelling advantages, in particular with respect to artificial metalloenzymes, which lead to a drastic increase in the throughput of screening campaigns and additionally are of unique value for future in vivo applications. Therefore, we highlight here the benefits of this strategy and intend to propose a generalized guideline for the development of novel transition metal-based biocatalysts by directed evolution in order to extend the natural enzymatic repertoire.

Influence of polyunsaturated fatty acids on vasoconstrictions induced by 8-iso-PGF(2alpha) and 8-iso-PGE(2).

8-iso-PGF(2alpha) and 8-iso-PGE(2), which are released in vivo by free radical catalyzed peroxidation of arachidonic acid, are equipotent vasoconstrictors in vivo and in vitro. It is assumed that they exert this effect via activation of the thromboxane A(2) (TP) receptor or a TP-receptor-like isoprostane receptor. Increased levels of 8-iso-PGF(2alpha) have been detected in human cardiovascular diseases. It has been found that polyunsaturated fatty acids (PUFAs) have many beneficial effects in cardiovascular diseases, including antivasoconstrictor actions. Therefore, we investigated the influence of perfusions with eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and dihomo-gamma-linolenic acid (DGLA) at final concentrations of 3 and 30 micromol/l on vasoconstriction induced by 8-iso-PGF(2alpha), 8-iso-PGE(2) and the thromboxane A(2) mimetic U 46619 in the vasculature of the isolated perfused rabbit ear. Additionally, the effect of indomethacin (final concentration 3 micromol/l) on the effects of the PUFAs was investigated. Our results show that the PUFAs at a concentration of 30 micromol/l caused a significant inhibition of the vasoconstrictions induced by 8-iso-PGF(2alpha), 8-iso-PGE(2) and U 46619. Furthermore, it can be assumed that a part of the inhibitory effect of DGLA is due to the effect of a cyclooxygenase product, probably PGE(1), because indomethacin reduced the inhibitory effect of DGLA.

Effects of low-molecular-weight dermatan sulfate on coagulation, fibrinolysis and tissue factor pathway inhibitor in healthy volunteers.

Low-molecular-weight (LMW)-dermatan sulfate (Desmin) with the mean molecular weight of 5600 Da has been obtained by limited depolymerization of natural dermatan sulfate. The pharmacokinetic and pharmacodynamic data of 100 and 200 mg were analyzed after intravenous injection and of 50, 100 and 200 mg after subcutaneous injection on tissue factor pathway inhibitor (TFPI) antigen and activity, heparin cofactor (HC) II activity, HeptestTM coagulation value, chromogenic S-2222 anti-factor Xa (aXa) assay, activated partial thromboplastin time (APTT), thrombin clotting time (TCT), plasminogen, tissue plasminogen activator activity (t-PA) and plasminogen activator inhibitor (PAI). After i.v.injection of 100 mg and 200 mg Desmin TFPI antigen and activity increased 2.2- and 2.7-fold, and returned to normal values within 60 and 90 min, respectively. Using the HC II assay the elimination half-lives (T1/2 el) increased from 1.9 h to 3.3 h with increasing doses of LMW-dermatan sulfate. T1/2 el were 4.3 and 6.9 h with the Heptest assay and 3.3 and 5.1 with the aXa method, respectively. APTT, TCT and the fibrinolytic parameters were not modified by either dose of i.v. LMW-dermatan sulfate. After s.c. administration of 100 mg or 200 mg LMW-dermatan sulfate no increase of TFPI antigen or activity was detected. T1/2 el was 5.6 h using HC II method, 11.1 h using Heptest and 7.8 h with the aXa activity. The total clearance was about ten-fold higher when determined by the HC II method compared with Heptest and aXa method. The volume of distribution (VD) increased with increasing doses of s.c. LMW-dermatan sulfate and was highest with the HC II method. Intravenous administration of 100 mg protamine chloride 15 min after i.v. dosing of 100 mg LMW-dermatan sulfate did not modify TFPI, coagulation or fibrinolytic parameters. Further analysis of the complex mechanism of action has to include studies which should explain the low release of TFPI in relation to the antithrombotic effects of LMW-dermatan sulfate.