Developmental Sex Differences in the Metabolism of Cardiolipin in Mouse Cerebral Cortex Mitochondria

Cardiolipin (CL) is a mitochondrial-specific phospholipid. CL content and acyl chain composition are crucial for energy production. Given that estradiol induces CL synthesis in neurons, we aimed to assess CL metabolism in the cerebral cortex (CC) of male and female mice during early postnatal life, when sex steroids induce sex-dimorphic maturation of the brain. Despite the fact that total amount of CL was similar, its fatty acid composition differed between males and females at birth. In males, CL was more mature (lower saturation ratio) and the expression of the enzymes involved in synthetic and remodeling pathways was higher, compared to females. Importantly, the sex differences found in CL metabolism were due to the testosterone peak that male mice experience perinatally. These changes were associated with a higher expression of UCP-2 and its activators in the CC of males. Overall, our results suggest that the perinatal testosterone surge in male mice regulates CL biosynthesis and remodeling in the CC, inducing a sex-dimorphic fatty acid composition. In male's CC, CL is more susceptible to peroxidation, likely explaining the testosterone-dependent induction of neuroprotective molecules such as UCP-2. These differences may account for the sex-dependent mitochondrial susceptibility after perinatal hypoxia/ischemia.Instituto de Investigaciones Bioquímicas de La Plat

Developmental Sex Differences in the Metabolism of Cardiolipin in Mouse Cerebral Cortex Mitochondria

Cardiolipin (CL) is a mitochondrial-specific phospholipid. CL content and acyl chain composition are crucial for energy production. Given that estradiol induces CL synthesis in neurons, we aimed to assess CL metabolism in the cerebral cortex (CC) of male and female mice during early postnatal life, when sex steroids induce sex-dimorphic maturation of the brain. Despite the fact that total amount of CL was similar, its fatty acid composition differed between males and females at birth. In males, CL was more mature (lower saturation ratio) and the expression of the enzymes involved in synthetic and remodeling pathways was higher, compared to females. Importantly, the sex differences found in CL metabolism were due to the testosterone peak that male mice experience perinatally. These changes were associated with a higher expression of UCP-2 and its activators in the CC of males. Overall, our results suggest that the perinatal testosterone surge in male mice regulates CL biosynthesis and remodeling in the CC, inducing a sex-dimorphic fatty acid composition. In male's CC, CL is more susceptible to peroxidation, likely explaining the testosterone-dependent induction of neuroprotective molecules such as UCP-2. These differences may account for the sex-dependent mitochondrial susceptibility after perinatal hypoxia/ischemia.Instituto de Investigaciones Bioquímicas de La Plat

The enzymatic determination of glucose in carbonated beverages: a useful tool for the undergraduate students to learn the basis of enzymatic analysis and the comparison of two analytical methods

The importance of enzymatic analysis in biochemistry, clinical chemistry and food chemistry is undoubted. The course "Applied Biochemistry" in our Faculty is aimed to undergraduate students of Chemistry and Biochemistry. In this subject, the principles and applications of enzymatic analysis are presented to the students, who receive a theoretical introductory lecture in the classroom before they carry out an experiment that should be feasible to be solved in a short laboratory period. The experimental protocol here presented, based on the enzymatic determination of glucose in carbonated beverages, has been implemented at the University of Málaga and it has been optimized according to the students’ results and commentaries along the last years. It aims to illustrate basic issues relating enzymatic analysis, including its potential application to food chemistry. Although there are several enzymatic methods that can be used for the determination of glucose, we selected the one based on the coupled reactions of glucose oxidase (GOD; EC 1.1.3.4.) and peroxidase (POD; EC 1.11.1.7.) because the kinetic constants of glucose oxidase allow the mentioned enzymatic reactions to be used in both, the end point and the kinetic enzymatic analysis methods. In this way, data for two different protocols for the determination of glucose concentration are obtained by the students from a single reaction mixture. Students construct a calibration curve for each method using a glucose standard solution, and use them to determine the glucose concentration in the problem solutions. The inclusion of replicate samples in the determination of the glucose concentration of an “ideal problem” (glucose in purified water) is used to illustrate the principles of statistics in the lab, and comparison with the “real value” allows an estimation of the accuracy of each method. The evaluation of glucose concentration in four carbonated beverages: coloured coke and uncoloured tonic sodas (regular or sugarless in both cases) makes student to recognise the appearance of interferences that should be either avoided or eliminated. Since all samples are analysed by means of end-point and kinetic methods, students can discuss the applicability of each method to these specific analytical problems. They are also encouraged to compare both analytical methods in terms of sensitivity, selectivity, accuracy, and time consumed. Chemistry and Biochemistry undergraduate students having performed this experiment in our laboratories have found it formative, interesting and challenging.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

A practice project to prevent the cookbook model as modus operandi for biochemistry laboratory learning

Laboratory learning is a crucial component of chemistry and biochemistry instruction and should be conceived as a way to develop students’ reasoning, technical or practical skills, introducing them into the scientific method principles. Nevertheless, the heavily criticized “expository instruction style”, characterized by a cookbook nature, is still the most widespread style of laboratory instruction in our universities. Alternative learning styles based in the inquiry, discovery and problem-based pedagogical approaches, have been reported to promote students’ problem solving skills, critical thought and self-confidence development. We are currently involved in the Educative Innovation Project PIE17-065, funded by University of Malaga, aimed to improve the teaching practice of Biochemistry laboratory to undergraduate students. Based on an enzymatic analysis of glucose in soft-drinks we have developed a laboratory protocol as a part of a full practice project where students must work before and after the lab session, in order to prevent the cookbook model as modus operandi, therefore preventing the situation where the students get a first glimpse of the experiment protocol whereas they put on their lab coat. The learning activities have been designed to move our students from the passive role that characterizes the step-by-step procedures, to an active and critical attitude that starts before and remains after their laboratory session, also minimizing time, space, and equipment resources. Our results have shown that this experiment has improved the learning of both, future biochemists and chemists, which showed a very positive perception of the whole practical project.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. PIE 17-06

Clinical and Neuropsychological Correlates of Prefrailty Syndrome

Physical frailty is closely associated with cognitive impairment. We aim to investigate the neuropsychological profiles of prefrail and non-frail dementia-free community-dwelling older adults using a comprehensive neuropsychological evaluation, and to examine the association between specific frailty criteria and clinical and neuropsychological scores. Participants completed a comprehensive standardized neuropsychological evaluation (covering cognitive domains such as memory, executive functions, language and attention), and frailty assessment. Frailty was assessed according to biological criteria: unintentional weight loss, exhaustion, low physical activity, slowness, and weakness. The sample comprised 60 dementia-free community-dwelling adults, aged 65 years or older (range 65-89 years; 60.0% women). Forty-two participants were classified as robust (no frailty criteria present), and 18 as prefrail (1 or 2 frailty criteria present). We explored neurocognitive differences between the groups and examined the association between specific criteria of frailty phenotype and clinical and neuropsychological outcomes with bivariate tests and multivariate models. Prefrail participants showed poorer cognitive performance than non-frail participants in both memory and non-memory cognitive domains. However, delayed episodic memory was the only cognitive subdomain that remained significant after controlling for age, gender, and educational level. Gait speed was significantly associated with general cognitive performance, immediate memory, and processing speed, while grip strength was associated with visual episodic memory and visuoconstructive abilities. Both gait speed and grip strength were negatively associated with depressive scores. Our results suggest that prefrailty is associated with cognitive dysfunction. The fact that specific cognitive domains may be susceptible to subclinical states of physical frailty may have important clinical implications. Indeed, early detection of specific cognitive dysfunctions may allow opportunities for reversibility

Epigenetic rather than genetic factors may explain phenotipic divergence between coastal populations of diploid and tetraploid Limonium spp. (Plumbaginaceae) in Portugal

Research ArticleBackground: The genus Limonium Miller comprises annual and perennial halophytes that can produce sexual and/or asexual seeds (apomixis). Genetic and epigenetic (DNA methylation) variation patterns were investigated in populations of three phenotypically similar putative sexual diploid species (L. nydeggeri, L. ovalifolium, L. lanceolatum), one sexual tetraploid species (L. vulgare) and two apomict tetraploid species thought to be related (L. dodartii, L. multiflorum). The extent of morphological differentiation between these species was assessed using ten diagnostic morphometric characters. Results: A discriminant analysis using the morphometric variables reliably assigns individuals into their respective species groups. We found that only modest genetic and epigenetic differentiation was revealed between species by Methylation Sensitive Amplification Polymorphism (MSAP). However, whilst there was little separation possible between ploidy levels on the basis of genetic profiles, there was clear and pronounced interploidy discrimination on the basis of epigenetic profiles. Here we investigate the relative contribution of genetic and epigenetic factors in explaining the complex phenotypic variability seen in problematic taxonomic groups such as Limonium that operate both apomixis and sexual modes of reproduction. Conclusions: Our results suggest that epigenetic variation might be one of the drivers of the phenotypic divergence between diploid and tetraploid taxa and discuss that intergenome silencing offers a plausible mechanistic explanation for the observed phenotypic divergence between these microspecies. These results also suggest that epigenetic profiling offer an additional tool to infer ploidy level in stored specimens and that stable epigenetic change may play an important role in apomict evolution and species recognitioninfo:eu-repo/semantics/publishedVersio

Learning contract, co-operative and flipped learning as useful tools for studying metabolism

Es el Abstract de una comunicación a un congreso internacional sobre educaciónUndergraduate students in Biology identify Metabolic Biochemistry as a particularly difficult subject. This is due to the fact that students need to interconnect properly all the contents of its syllabus throughout their study of the subject in order to get a global insight of the complex regulatory features controlling metabolic pathways within the metabolic network under different physiologic and pathologic conditions, as well as metabolism as a whole. Due to these objective difficulties, a high percentage of our students face the study of this subject as a very hard task beyond their forces and capacities. This perception leads to high rates of premature dropout. In previous years, less than 40% of all the registered students attended the examinations of Metabolic Biochemistry (a subject in the second year of the Degree of Biology at our University). Even worse, less than 25% of our students passed the exams. From the academic year 2015/16 on, we are developing innovative teaching projects (PIE15-163 and PIE17-145, funded by University of Malaga) aimed to increase our student loyalty to the subject (and hence to increase their attendance to exams) and to help them to learn more effectively metabolism and its regulation. These innovative teaching projects are based on the use of several powerful tools: a learning contract and problem-based learning within the framework of group tasks promoting an actual collaborative learning in a flipped classroom. The present communication will show the implementation of the PIE15-163 and PIE17-145 projects and some results obtained from them.This work was supported by Malaga University funds granted to the educational innovation project PIE17-145. The attendance to the END2018 International Conference on Education and New Developments (June 2018, Budapest, Hungary) has received a grant from "I Plan Propio Integral de Docencia. Universidad de Málaga"]

Influence of climate variables on resin yield and secretory structures in tapped Pinus pinaster Ait. in central Spain

The role of climate and soil water availability on resin yield was evaluated. Resin yield increased with temperature, radiation and evapotranspiration values. Resin yield and axial canal size were correlated with water deficit in spring. Above a certain threshold of cumulated water deficit, summer rainfall favored resin yield. Stand density and soil quality affected the relations between climate and resin yield