Maternal dietary methionine restriction alters the expression of energy metabolism genes in the duckling liver

International audienceBackground In mammals, the nutritional status experienced during embryonic development shapes key metabolic pathways and influences the health and phenotype of the future individual, a phenomenon known as nutritional programming. In farmed birds as well, the quantity and quality of feed offered to the dam can impact the phenotype of the offspring. We have previously reported that a 38% reduction in the intake of the methyl donor methionine in the diet of 30 female ducks during the growing and laying periods - from 10 to 51 weeks of age - reduced the body weight of their 180 mule ducklings compared to that of 190 ducklings from 30 control females. The maternal dietary methionine restriction also altered the hepatic energy metabolism studied in 30 of their ducklings. Thus, their plasma glucose and triglyceride concentrations were higher while their plasma free fatty acid level was lower than those measured in the plasma of 30 ducklings from the control group. The objective of this new study was to better understand how maternal dietary methionine restriction affected the livers of their newly hatched male and female ducklings by investigating the hepatic expression levels of 100 genes primarily targeting energy metabolism, amino acid transport, oxidative stress, apoptotic activity and susceptibility to liver injury. Results Sixteen of the genes studied were differentially expressed between the ducklings from the two groups. Maternal dietary methionine restriction affected the mRNA levels of genes involved in different pathways related to energy metabolism such as glycolysis, lipogenesis or electron transport. Moreover, the mRNA levels of the nuclear receptors PPARGC1B, PPARG and RXRA were also affected. Conclusions Our results show that the 38% reduction in methionine intake in the diet of female ducks during the growing and egg-laying periods impacted the liver transcriptome of their offspring, which may explain the previously observed differences in their liver energy metabolism. These changes in mRNA levels, together with the observed phenotypic data, suggest an early modulation in the establishment of metabolic pathways

Maternal dietary methionine restriction alters hepatic expression of one-carbon metabolism and epigenetic mechanism genes in the ducklings

International audienceAbstract Background Embryonic and fetal development is very susceptible to the availability of nutrients that can interfere with the setting of epigenomes, thus modifying the main metabolic pathways and impacting the health and phenotypes of the future individual. We have previously reported that a 38% reduction of the methyl donor methionine in the diet of 30 female ducks reduced the body weight of their 180 mule ducklings compared to that of 190 ducklings from 30 control females. The maternal methionine-restricted diet also altered plasmatic parameters in 30 of their ducklings when compared to that of 30 ducklings from the control group. Thus, their plasma glucose and triglyceride concentrations were higher while their free fatty acid level and alanine transaminase activity were decreased. Moreover, the hepatic transcript level of 16 genes involved in pathways related to energy metabolism was significantly different between the two groups of ducklings. In the present work, we continued studying the liver of these newly hatched ducklings to explore the impact of the maternal dietary methionine restriction on the hepatic transcript level of 70 genes mostly involved in one-carbon metabolism and epigenetic mechanisms. Results Among the 12 genes ( SHMT1 , GART , ATIC , FTCD , MSRA , CBS , CTH , AHCYL1 , HSBP1 , DNMT3 , HDAC9 and EZH2 ) identified as differentially expressed between the two maternal diet groups ( p -value < 0.05), 3 of them were involved in epigenetic mechanisms. Ten other studied genes ( MTR , GLRX , MTHFR , AHCY , ADK , PRDM2 , EEF1A1 , ESR1 , PLAGL1 , and WNT11 ) tended to be differently expressed (0.05 < p -value < 0.10). Moreover, the maternal dietary methionine restriction altered the number and nature of correlations between expression levels of differential genes for one-carbon metabolism and epigenetic mechanisms, expression levels of differential genes for energy metabolism, and phenotypic traits of ducklings. Conclusion This avian model showed that the maternal dietary methionine restriction impacted both the mRNA abundance of 22 genes involved in one-carbon metabolism or epigenetic mechanisms and the mRNA abundance of 16 genes involved in energy metabolism in the liver of the newly hatched offspring, in line with the previously observed changes in their phenotypic traits

Thermorégulation des porcelets issus de deux lignées divergentes pour l’efficacité alimentaire

Hypothermia is a factor of piglet neonatal mortality. This study used Infra-Red Thermography (IRT) to assess thermoregulation abilities of piglets from two lines divergent for residual feed intake (RFI). Birth phenotypes (e.g. body weight, rectal temperature, physical measures, vitality test) were recorded from piglets selected for low RFI (more efficient; LRFI; n=34) or high RFI (less efficient; HRFI; n=28). The IRT images were taken at 8, 15, 30 and 60 min post-partum. Temperatures of the ear base and tip, and minimum, maximum and average temperatures of the back (i.e. shoulders to rumps) were extracted with Thermacam Researcher Pro 2.0 and analysed with linear mixed models. No difference in phenotypic data was detected between the two lines. All temperatures increased over time. Rectal temperature of piglets at birth was correlated with the initial temperature of the ear base and the maximum back temperature (0.36 and 0.35, respectively, P < 0.05). Overall, LRFI piglets, compared to HRFI piglets, had higher minimum (28.0 ± 0.2 °C vs 26.8 ± 0.2 °C, respectively, P < 0.001) and average (35.5 ± 0.2 °C vs 34.5 ± 0.1 °C, respectively, P < 0.001) back temperatures. Ear tip temperature decreased in HRFI piglets from 8 to 15 min post-partum, while it increased in LRFI piglets (-1.1 ± 0.4 °C vs 0.5 ± 0.5 °C, respectively, P < 0.05). In conclusion, IRT allowed non-invasive assessment of piglets’ thermoregulation abilities. Piglets selected for low RFI seemed to have better thermoregulation abilities at birth

PROGRAMMATION NUTRITIONNELLE DU METABOLISME HEPATIQUE CHEZ LE CANETON MULARD : ETUDE DE TRANSCRITS

National audienceNutritional programming of hepatic metabolism in mule ducks: a transcript studyIn farmed birds, the quantity and quality of the maternal diet can affect the production performances of theoffspring. We have already shown that maternal dietary methionine restriction (0.25% versus 0.40%) affectsparameters of liver metabolism in mule ducklings. The hepatic expression level of 170 targeted genes allowed usto identify 55 differentially expressed genes between the two groups of ducklings. Among them, some wererelated to energy metabolism and others concerned the one-carbon metabolism and some epigeneticmechanisms. These early changes in transcript levels, together with the observed phenotypic data, suggestmodulation in the establishment of early metabolic pathways that may pave the way for long-term effects onenergy metabolism. Indeed, at 12 weeks of age, mule ducks from the methionine-restricted group showed lowerliver lipid percentage together with a lower abdominal fat weight. After force-feeding, fatty liver weight wasreduced by more than 10% (495 g versus 546 g; P = 0.003). This led us to propose a metabolic interactionscheme linking one-carbon metabolism and energy metabolism. This work thus highlights the link etweenmaternal nutrition and production performance in mule ducksChez les oiseaux, la qualité de l'alimentation maternelle peut impacter les performances de la progéniture. Nous avons ainsi montré que chez le canard mulard, un régime alimentaire maternel restreint en méthionine (0,25% versus 0,40%) affecte certains paramètres du métabolisme hépatique des canetons des deux sexes. Une évaluation du niveau d'expression hépatique de 170 gènes cibles nous a permis d'identifier 55 gènes différentiellement exprimés entre les deux groupes de canetons. Parmi eux, certains concernent le métabolisme énergétique et d'autres concernent le métabolisme du monocarbone et quelques mécanismes épigénétiques. Ces changements des niveaux des transcrits, ainsi que les données phénotypiques observées, suggèrent une modulation dans l'établissement de voies métaboliques précoces pouvant ainsi constituer la base des effets à long terme observés sur le métabolisme énergétique. En effet, à 12 semaines d'âge, les mulards issus de canes restreintes en méthionine ont un taux de lipides hépatiques et un poids de gras abdominal plus faibles et, après gavage, le poids du foie gras est diminué de plus de 10 % (495 g versus 546 g ; P = 0,003). Ceci nous a conduits à proposer un schéma d'interactions métaboliques reliant le métabolisme du monocarbone et le métabolisme énergétique. Ces travaux soulignent le lien entre alimentation maternelle et performances de gavage chez le canard mulard

Placenta and adrenal adaptation according to piglet genetic potential for maturity at birth

Placenta and adrenal adaptation according to piglet genetic potential for maturity at birth. 10. International Conference on Pig Reproduction (ICPR

Nuclear RNA surveillance complexes silence HIV-1 transcription

<div><p>Expression from the HIV-1 LTR can be repressed in a small population of cells, which contributes to the latent reservoir. The factors mediating this repression have not been clearly elucidated. We have identified a network of nuclear RNA surveillance factors that act as effectors of HIV-1 silencing. RRP6, MTR4, ZCCHC8 and ZFC3H1 physically associate with the HIV-1 TAR region and repress transcriptional output and recruitment of RNAPII to the LTR. Knock-down of these factors in J-Lat cells increased the number of GFP-positive cells, with a concomitant increase in histone marks associated with transcriptional activation. Loss of these factors increased HIV-1 expression from infected PBMCs and led to reactivation of HIV-1 from latently infected PBMCs. These findings identify a network of novel transcriptional repressors that control HIV-1 expression and which could open new avenues for therapeutic intervention.</p></div

RRP6, MTR4, ZFC3H1/ZCCHC8 silence LTR-driven transcription.

<p>(A) HeLa-LTR-luc cells were transfected with siRNAs directed against RRP6, MTR4, ZFC3H1, ZCCHC8, ZFC3H1+ZCCHC8 or a control siRNA (Scr). Cell extracts were harvested at 60 hr and analyzed by immunoblotting using the antibodies indicated. Values shown above the blots represent the intensity of the bands relative to the control transfection (Scr) samples, which were set to 100%. (B) Schematic diagram showing the locations of primers used to amplify sequences by Q-PCR. The <i>luciferase</i> reporter gene is shown as a white box. TAR RNA stem-loop is indicated at the 5’ end of the transcript. Primers used to amplify TAR and coding region sequences are indicated on the figure. (C) Total RNA isolated from cells described in A was analyzed by RT-q-PCR using the oligonucleotide pairs indicated, and GAPDH. The amount of the indicated mRNA was normalized to the amount of GAPDH mRNA in each sample, and the values were normalized to those for the control transfection (Scr), which was attributed a value of 1. Data represent mean ± SEM obtained from 3 independent experiments (**<i>P</i> < 0.01, *<i>P</i> < 0.05, independent Student’s <i>t</i> test). (D) HeLa-LTR-luc cells transfected with the indicated siRNAs were analyzed by nuclear run-on transcription. RT-q-PCR was performed using the indicated primer pairs. Results are shown relative to a control sample (scr), which was attributed a value of 1. Data represent mean ± SEM obtained from 3 independent experiments (**<i>P</i> < 0.01, *<i>P</i> < 0.05, independent Student’s <i>t</i> test). (E) HeLa-LTR-luc cells transfected with the indicated siRNAs were analyzed by chromatin immunoprecipitation for RNAPII. PCR was performed using the indicated primer pairs. Results are shown relative to an IgG control. Data represent mean ± SEM obtained from 3 independent experiments (**<i>P</i> < 0.01, *<i>P</i> < 0.05, independent Student’s <i>t</i> test).</p

Ablation of RRP6, MTR4 and ZFC3H1/ZCCHC8 stimulates LTR-directed transcript abundance.

<p>(A) HeLa-LTR-luc cells were transfected with siRNAs directed against RRP6, MTR4, ZFC3H1, ZCCHC8 or a control siRNA (Scr). Cell extracts were harvested at 60 hr post-transfection and analyzed by luciferase assay and immunoblotting using the antibodies indicated. Values shown above the blots represent the intensity of the bands relative to the control transfection (Scr) samples, which were set to 100%. Fold activation was calculated relative to the control transfection (Scr), which was attributed a value of 1. Data represent mean ± SEM obtained from 3 independent experiments (**<i>P</i> < 0.01, *<i>P</i> < 0.05, independent Student’s <i>t</i> test). (B) HeLa-LTR-luc cells were transfected with siRNAs directed against ZFC3H1, ZCCHC8 either alone or in combination, or a control siRNA (Scr). Cell extracts were harvested at 60 hr post-transfection and analyzed by luciferase assay and immunoblotting using the antibodies indicated. Values shown above the blots represent the intensity of the bands relative to the control transfection (Scr) samples, which were set to 100%. Fold activation was calculated relative to the control transfection (Scr), which was attributed a value of 1. Data represent mean ± SEM obtained from 3 independent experiments (**<i>P</i> < 0.01, *<i>P</i> < 0.05, independent Student’s <i>t</i> test).</p