Pyrroloquinoline quinone nutritional status alters lysine metabolism and modulates mitochondrial DNA content in the mouse and rat

Pyrroloquinoline quinone (PQQ) added to purified diets devoid of PQQ improves indices of perinatal development in rats and mice. Herein, PQQ nutritional status and lysine metabolism are described, prompted by a report that PQQ functions as a vitamin-like enzymatic cofactor important in lysine metabolism (Nature 422 [2003] 832). Alternatively, we propose that PQQ influences lysine metabolism, but by mechanisms that more likely involve changes in mitochondrial content. PQQ deprivation in both rats and mice resulted in a decrease in mitochondrial content. In rats, alpha-aminoadipic acid (alphaAA), which is derived from alpha-aminoadipic semialdehyde (alphaAAS) and made from lysine in mitochondria, and the plasma levels of amino acids known to be oxidized in mitochondria (e.g., Thr, Ser, and Gly) were correlated with changes in the liver mitochondrial content of PQQ-deprived rats, but not PQQ-supplemented rats. In contrast, the levels of NAD dependent alpha-aminoadipate-delta-semialdehyde dehydrogenase (AASDH), a cytosolic enzyme important to alphaAA production from alphaAAS, was not influenced by PQQ dietary status. Moreover, the levels of U26 mRNA were not significantly changed even when diets differed markedly in PQQ and dietary lysine content. U26 mRNA levels were measured, because of U26's proposed, albeit questionable role as a PQQ-dependent enzyme involved in alphaAA formation.     

Neuroprotective Effects of Methyl-3-O-methyl gallate Against Sodium Fluoride-Induced Oxidative Stress in the Brain of Rats

Methyl-3-O-methyl gallate (M3OMG) is a rare natural product that showed promising in vitro antioxidant activities. In this study, the protective role of synthetic M3OMG against sodium fluoride (NaF)-induced oxidative stress in rat brain was evaluated. Animals were treated with either M3OMG (10 and 20 mg/kg i.p.), vitamin C (10 mg/kg i.p.) as the standard antioxidant or the vehicle (5 % dimethyl sulfoxide; 1 ml/kg) for 1 week. Oxidative stress was induced in the brain by adding 600 ppm NaF in the drinking water for 7 days. At the end of the treatment period, the levels of thiobarbituric acid reactive substances (TBARS), reduced glutathione and the activities of antioxidant enzymes (superoxide dismutase and catalase) were evaluated in brain homogenates. M3OMG treatment mitigated the NaF-induced oxidative stress through normalization of the level of TBARS, reduced levels of glutathione and by the restoration of the diminished antioxidant enzyme activities. In conclusion, M3OMG could have a potential for treating neurotoxicity induced by fluoride or related environmental pollutants.     

Effects of Arsenic on Growth, Photosynthetic Activity, and Accumulation in Two New Hyperaccumulating Populations of Isatis cappadocica Desv.

The effect of arsenic on leaf photosynthetic rate, growth responses, and accumulation capability of Isatis cappadocica Desv., a Brassica collected from Iranian arsenic-contaminated mine spoils and control populations, was investigated. Both populations of I. cappadocica were considerably more tolerant than the reference Brassica species (Descurainia sophia). The 1,000 μM arsenate exposure inhibited root growth completely in D. sophia, but only by 50 and 40 % in the nonmine and mine populations of I. cappadocica, respectively. Furthermore, the chlorophyll contents of both populations of I. cappadocica were not statistically different, especially when plants were exposed to 5–800 μM As. The chlorophyll a fluorescence kinetics (F _v/F _m) and electron transfer rate values of treated I. cappadocica populations remained unaffected, indicating normal photosynthetic efficiency and strength of plants in the presence of arsenic. After 28 days of exposure to 1,300 μM As, shoot arsenic concentrations of mine and nonmine populations reached 310 and 345 mg kg^?1, respectively, with the arsenic transfer factor and bioaccumulation greater than 1.0. According to these results, it was shown that I. cappadocica had strong tolerance to and the capability to hyperaccumulate arsenic; therefore, it is a potential As hyperaccumulator.     

The Role of α7 Nicotinic Acetylcholine Receptor in Modulation of Heart Rate Dynamics in Endotoxemic Rats

Previous reports have indicated that artificial stimulation of the vagus nerve reduces systemic inflammation in experimental models of sepsis. This phenomenon is a part of a broader cholinergic anti-inflammatory pathway which activates the vagus nerve to modulate inflammation through activation of alpha7 nicotinic acetylcholine receptors (α7nACHR). Heart rate variability represents the complex interplay between autonomic nervous system and cardiac pacemaker cells. Reduced heart rate variability and increased cardiac cycle regularity is a hallmark of clinical conditions that are associated with systemic inflammation (e.g. endotoxemia and sepsis). The present study was aimed to assess the role of α7nACHR in modulation of heart rate dynamics during systemic inflammation. Systemic inflammation was induced by injection of endotoxin (lipopolysaccharide) in rats. Electrocardiogram and body temperature were recorded in conscious animals using a telemetric system. Linear and non-linear indices of heart rate variability (e.g. sample entropy and fractal-like temporal structure) were assessed. RT-PCR and immunohistochemistry studies showed that α7nACHR is expressed in rat atrium and is mainly localized at the endothelial layer. Systemic administration of an α7nACHR antagonist (methyllycaconitine) did not show a significant effect on body temperature or heart rate dynamics in naïve rats. However, α7nACHR blockade could further reduce heart rate variability and elicit a febrile response in endotoxemic rats. Pre-treatment of endotoxemic animals with an α7nACHR agonist (PHA-543613) was unable to modulate heart rate dynamics in endotoxemic rats but could prevent the effect of endotoxin on body temperature within 24 h experiment. Neither methyllycaconitine nor PHA-543613 could affect cardiac beating variability of isolated perfused hearts taken from control or endotoxemic rats. Based on our observations we suggest a tonic role for nicotinic acetylcholine receptors in modulation of heart rate dynamics during systemic inflammation.     

Structural stability of myoglobin and glycomyoglobin: a comparative molecular dynamics simulation study

Glycoproteins are formed as the result of enzymatic glycosylation or chemical glycation in the body, and produced in vitro in industrial processes. The covalently attached carbohydrate molecule(s) confer new properties to the protein, including modified stability. In the present study, the structural stability of a glycoprotein form of myoglobin, bearing a glucose unit in the N-terminus, has been compared with its native form by the use of molecular dynamics simulation. Both structures were subjected to temperatures of 300 and 500 K in an aqueous environment for 10 ns. Changes in secondary structures and RMSD were then assessed. An overall higher stability was detected for glycomyoglobin, for which the most stable segments/residues were highlighted and compared with the native form. The simple addition of a covalently bound glucose is suggested to exert its stabilizing effect via increased contacts with surrounding water molecules, as well as a different pattern of interactions with neighbor residues.

Electronic supplementary material

The online version of this article (doi:10.1007/s10867-015-9383-2) contains supplementary material, which is available to authorized users.     

Inequalities in Maternal Health Care Utilization in Sub-Saharan African Countries: A Multiyear and Multi-Country Analysis

To assess social inequalities in the use of antenatal care (ANC), facility based delivery (FBD), and modern contraception (MC) in two contrasting groups of countries in sub-Saharan Africa divided based on their progress towards maternal mortality reduction. Six countries were included in this study. Three countries (Ethiopia, Madagascar, and Uganda) had <350 MMR in 2010 with >4.5% average annual reduction rate while another three (Cameroon, Zambia, and Zimbabwe) had >550 MMR in 2010 with only <1.5% average annual reduction rate. All of these countries had at least three rounds of Demographic and Health Surveys (DHS) before 2012. We measured rate ratios and differences, as well as relative and absolute concentration indices in order to examine within-country geographical and wealth-based inequalities in the utilization of ANC, FBD, and MC. In the countries which have made sufficient progress (i.e. Ethiopia, Madagascar, and Uganda), ANC use increased by 8.7, 9.3 and 5.7 percent, respectively, while the utilization of FBD increased by 4.7, 0.7 and 20.2 percent, respectively, over the last decade. By contrast, utilization of these services either plateaued or decreased in countries which did not make progress towards reducing maternal mortality, with the exception of Cameroon. Utilization of MC increased in all six countries but remained very low, with a high of 40.5% in Zimbabwe and low of 16.1% in Cameroon as of 2011. In general, relative measures of inequalities were found to have declined overtime in countries making progress towards reducing maternal mortality. In countries with insufficient progress towards maternal mortality reduction, these indicators remained stagnant or increased. Absolute measures for geographical and wealth-based inequalities remained high invariably in all six countries. The increasing trend in the utilization of maternal care services was found to concur with a steady decline in maternal mortality. Relative inequality declined overtime in countries which made progress towards reducing maternal mortality.     

Genetic and environmental effects on age at menarche,and its relationship with reproductive health in twins

INTRODUCTION:

Menarche or first menstrual period is a landmark in reproductive life span and it is the most prominent change of puberty. The timing of menarche can be under the influence of genes as well as individual environmental factors interacting with genetic factors.

OBJECTIVE:

Our study objectives were (a) to investigate the heritability of age of menarche in twins, (b) to obtain the association between age of menarche and childhood factors, and reproductive events/behavior, (c) to examine whether or not having a male co-twin affects early/late menarche.

METHODOLOGY:

A group of female-female identical (n = 108, 54 pairs), non-identical twins (n = 68, 34 pairs) and 17 females from opposite-sex twin sets were identified from twin registries of Malaysia and Iran. Genetic analysis was performed via two methods of Falconers’ formula and maximum likelihood.

RESULTS:

Heritability was found to be 66% using Falconers’ formula and 15% using univariate twin analysis. Model analysis revealed that shared environmental factors have a major contribution in determining the age of menarche (82%) followed by non-shared environment (18%).

DISCUSSION:

Result of this study is consistent with that of the literature. Timing of menarche could be under the influence of shared and non-shared environmental effects. Hirsutism was found to have a higher frequency among subjects with late menarche. There was no significant difference in age of menarche between females of opposite-sex twins and females of same-sex twins.

CONCLUSION:

It is concluded that twin models provide a powerful means of examining the total genetic contribution to age of menarche. Longitudinal studies of twins may clarify the type of environmental effects that determine the age of menarche.     

Effects of Sowing Time and Chemical,Organic, and Biological Fertilizer Sources on Yield Components and Antioxidant Properties of Dragon’s Head (Lallemantia iberica (M. Bieb.) Fisch. & C. A. Mey)

Journal of Plant Growth Regulation - The effects of winter and spring sowing and chemical, organic, and biological fertilizer sources were studied on yield components and antioxidant properties of...