Effect of maternal obesity and preconceptional weight loss on male and female offspring metabolism and olfactory performance in mice

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. According to the “developmental origins of health and disease” (DOHaD) concept, maternal obesity predisposes the offspring to non-communicable diseases in adulthood. While a preconceptional weight loss (WL) is recommended for obese women, its benefits on the offspring have been poorly addressed. We evaluated whether preconceptional WL was able to reverse the adverse effects of maternal obesity in a mouse model, exhibiting a modification of foetal growth and of the expression of genes encoding epigenetic modifiers in liver and placenta. We tracked metabolic and olfactory behavioural trajectories of offspring born to control, obese or WL mothers. After weaning, the offspring were either put on a control diet (CD) or a high-fat (HFD). After only few weeks of HFD, the offspring developed obesity, metabolic alterations and olfactory impairments, independently of maternal context. However, male offspring born to obese mother gained even more weight under HFD than their counterparts born to lean mothers. Preconceptional WL normalized the offspring metabolic phenotypes but had unexpected effects on olfactory performance: a reduction in olfactory sensitivity, along with a lack of fasting-induced, olfactory-based motivation. Our results confirm the benefits of maternal preconceptional WL for male offspring metabolic health but highlight some possible adverse outcomes on olfactory-based behaviours

Construction of an expression vector for the fission yeast Schizosaccharomyces pombe.

We have isolated and characterized a S. pombe promoter using a functional heterologous gene product assay. Random S. pombe genomic fragments were cloned upstream from the promoterless 'lacZ gene and tested in vivo for their efficiency to promote expression of the beta-galactosidase protein in the fission yeast. An efficient S. pombe promoter called 54/1 was isolated and shown to drive up to 5% of total protein synthesis as beta-galactosidase. The structure and nucleotide sequence of this promoter were determined, precise localization of its mRNA transcriptional start points established. Translational fusion of the Pseudomonas putida XylE gene with the 54/1 gene was shown to allow expression of catechol oxidase activity in S. pombe. An expression vector suitable for transcriptional fusions was then constructed from engineered 54/1 promoter sequences and used to drive expression of the E. coli Tn5 ble gene, thus confering resistance to the fission yeast against bleomycin and phleomycin antibiotics

Artificial milk preference of newborn lambs is prenatally influenced by transfer of the flavor from the maternal diet to the amniotic fluid

International audienceThe present study examined in lambs whether exposure to flavors derived from pregnant mother‘s diet and transferred to amniotic fluid (AF) could induce a preference for artificial milk containing one of these flavors. To test this hypothesis, cumin was added to the maternal diet in the last month of gestation. Preference for artificial milk containing p-cymene, one of the chemosensory compounds of cumin, was tested within the first two days after birth in maternally deprived lambs born from mothers fed a cumin-flavored diet (Cumin group), or an unflavored diet (Control group). Aromatic profile of AF from cumin-fed mothers was analyzed by GC-MS/MS to determine whether p-cymene could be detected. While the control group avoided the flavored artificial milk on day 1, the Cumin group did not and showed a preference for the cumin-scented formula on day 2. GC-MS/MS profile of AF revealed that four of the main volatile cumin compounds, p-cymene, p-cymenene, β-pinene and γ-terpinene were present in variable amounts in all samples, p-cymene being the most frequently detected. These findings indicate that newborn lambs can memorize flavors from the mother's diet present in AF and that prenatal experience influences their preference for an artificial milk containing one specific flavor

Amplification of the electrochemical signal of an olfactory receptor based biosensor by in situ generated gold nanoparticles

International audienceIn this work we present a biosensor based on olfactory receptors as a new bioelectronic device for detecting the presence and for measuring the concentration of specific odorants. To increase the surface of transducers, and consequently amplify the electrochemical signal, we generated gold nanoparticles on the surface of gold electrode. The characterization of the nanoparticles modified electrode surface allow to determine an increase of the surface area by a factor of 2.6 +/-. 0.4 (n = 4). Nanosomes from yeast containing olfactory receptor OR1740 with a cmyc tag were put in contact with the anti-cmyc antibody modified electrodes. Immobilization of nanosomes led to an increase in charge transfer resistance. This effect is amplified in the presence of gold nanoparticles by a factor of 3 +/- 0.5

A novel Detection Strategy for Odorant Molecules Based on Controlled Bioengineering of Rat Olfactory Receptor I7

In this study, we report a dose-dependent detection of odorant molecules in solution by rat olfactory receptor I7 (OR I7) in its membrane fraction. The OR I7 is immobilized on a gold electrode by multilayer bioengineering based on a mixed self-assembled monolayer and biotin/avidin system, which allows for a well-controlled immobilization of the bioreceptor within its lipid environment. The odorant detection is electronically performed in a quantitative manner by electrochemical impedance spectroscopy

Immobilization of rhodopsin on a self-assembled multilayer and its specific detection by electrochemical impedance spectroscopy.

Rhodopsin, the G protein coupled receptor (GPCR) which mediates the sense of vision, was prepared from calf eyes and used as receptor enriched membrane fraction. In this study it was immobilized onto gold electrode by two different techniques: Langmuir–Blodgett (LB) and a strategy based on a self-assembled multilayer. We demonstrated that Langmuir and LB films of rhodopsin are not stable. Thus, in this study a new protein multilayer was prepared on gold electrode by building up layer-by-layer a self-assembled multilayer. It is composed of a mixed self-assembled monolayer formed by MHDA and biotinyl-PE, followed by a biotin–avidin system which allows binding of biotinylated antibody specific to rhodopsin. The immobilization of rhodopsin in membrane fraction, by the specific antibody bound previously on selfassembled multilayer, was monitored with electrochemical impedance spectroscopy (EIS). In addition, the specificity and sensitivity of this self-assembled multilayer system to the presence of rhodopsin were investigated. No effect was observed when the system was in contact with olfactory receptor I7 in membrane fraction used for control measurements. All these results demonstrate that rhodopsin can be immobilized efficiently, specifically, quantitatively and stably on gold electrode through the self-assembled multilayer

Towards the Realization of Nanobiosensors Based on G Protein-Coupled Receptors

reserved19C. Pennetta; V. Akimov; E. Alfinito; L. Reggiani; T. Gorojankina; J. Minic; E. Pajot-Augy; M. A. Persuy and R. Salesse; I. Casuso; A. Errachid; G. Gomila; O. Ruiz; J. Samitier; Y. Hou; N. Jaffrezic; G. Ferrari; L. Fumagalli; M. Sampietro;C., Pennetta; V., Akimov; E., Alfinito; L., Reggiani; T., Gorojankina; J., Minic; E., Pajot Augy; M. A., Persuy; R., Salesse; I., Casuso; A., Errachid; G., Gomila; O., Ruiz; J., Samitier; Y., Hou; N., Jaffrezic; Ferrari, Giorgio; Fumagalli, Laura; Sampietro, Marc

Advances in the Production, Immobilization and Electrical Characterization of Olfactory Receptors for Olfactory Nanobiosensor Development

The animal olfactory system represents the gold standard of olfactory biosensors with its capability to identify and discriminate thousands of odorant compounds. In order to mimic the performances of natural olfactory sensors it is necessary to develop methods and techniques for the production, immobilization and electrical characterization of olfactory receptors. We present in this paper some of the advances we obtained in these fields