Hepatic and muscular transcriptomic responses of porcine progeny to gestational diets varying in protein content

Inadequate maternal protein supply during gestation represents an environmental factor that is known to affect physiological signaling pathways and impacts the phenotype of the progeny in animal models and in humans with long-term consequences for growth, function and structure of various tissues. The provoked intrauterine adaptive responses are termed 'Fetal Programming'. Hypothesising that the progeny's transcriptome is persistently altered by maternal diets, we used a porcine model to monitor the longitudinal expression changes in liver and muscle tissue to identify pathways relevant to fetal initiation of postnatal growth and development. Throughout the whole pregnancy nulliparous German landrace sows were fed one of three isoenergetic diets differing in their protein:carbohydrate ratio, resulting in a low protein diet (LP: 6.5 % crude protein), a high protein diet (HP: 30 % crude protein) and an adequate protein diet (AP: 12.1 % crude protein). All progeny was nursed by foster sows that received a standard diet. Postweaning, the progeny was fed standard diets ad libitum. The progeny's liver (n = 192) and muscle tissue M. longissimus dorsi; n = 72) were collected at 94 days post conception (dpc) and 1, 28, and 188 days post natum (dpn) for expression profiling. The analyses included comparisons between dietary groups within ontogenetic stages as well as comparisons between ontogenetic stages within dietary groups to separate diet-specific transcriptional changes and maturation processes. An in utero exposure to adverse gestational protein diets revealed a 'Programming' of the progeny's genome in a diet-, tissue- and stage-dependent manner. Transcriptional alterations during pre- and postnatal development differed considerably among dietary groups, particularly for genes related to energy metabolism, lipid metabolism, cell cycle regulation, organismal and cellular growth, and glucocorticoid receptor signaling. No single gene was found differentially expressed between the groups along all examined stages. The transcriptional responses in both HP and LP progeny were interpreted as the molecular equivalent to developmental plasticity which accounts for adaptation and maintenance of the organismal phenotype and affects signaling pathways related to energy utilisation. Obviously, the 'Fetal Programming' of the genome warrants adaptation processes regarding to compensatory growth, probably at the expense of a predisposition for metabolic disturbances up to adult stages.Transkriptionelle Antworten auf Trächtigkeitsdiäten unterschiedlicher Proteingehalte in porcinen Nachkommen Ungünstige Umwelteinflüsse während der fetalen Entwicklung bewirken eine intrauterine adaptive Antwort mit langfristigen Konsequenzen auf Wachstum, Funktion und Struktur verschiedener Gewebe der Nachkommen. Diese Zusammenhänge werden als 'Fetale Programmierung' bezeichnet. So stellt eine unangepasste maternale Proteinversorgung während der Gestation einen Umweltfaktor dar, der sowohl physiologische Signalwege beeinflusst als auch phänotypische Anpassungen bei Nachkommen von Mensch und Tier hervorruft. In der vorliegenden Arbeit wurde die Hypothese einer persistenten Transkriptomregulation der Nachkommen in Abhängigkeit von der mütterlichen Diät in einem porcinen Model bearbeitet. Ziel war es, molekulare Signalwege und Mechanismen mit Relevanz zur fetalen Initiierung von postnatalem Wachstum und Entwicklung zu identifizieren. Jungsauen der Deutschen Landrasse wurden während der gesamten Trächtigkeit mit einer von drei isoenergetischen Diäten ernährt, die sich in ihrem Protein:Kohlenhydrat-Verhältnis unterschieden. Die experimentellen Gruppen wurden als Niedrigproteindiät (LP, 6% Rohprotein, Protein:Kohlenhydrat 1:10), Hochproteindiät (HP, 30% Rohprotein, Protein:Kohlenhydrat 1:1,3) und adäquate Proteindiät (AP, 12% Rohprotein, Protein:Kohlenhydrat 1:5) bezeichnet. Die Nachkommen wurden von Ammensauen gesäugt, welche mit Standardfutter ernährt wurden. Nach dem Absetzen erhielten die Nachkommen Standardfutter ad libitum. Um Genexpressionsprofile abzubilden, wurde der Nachkommenschaft Leber (n = 192) und Muskelgewebe M. longissimus dorsi; n = 72) am 94. Tag der Trächtigkeit (dpc) sowie am 1., 28., und 188. Lebenstag (dpn) entnommen. Durch das longitudinale Studiendesign konnten sowohl Vergleiche zwischen Diätgruppen innerhalb der ontogenetischen Stadien als auch Vergleiche zwischen ontogenetischen Stadien innerhalb der einzelnen Diätgruppen vorgenommen werden. Auf diese Weise war es möglich, Diät-spezifische transkriptionelle Änderungen von physiologischen Reifungsprozessen zu unterscheiden. Die in utero Exposition zu nicht bedarfsgerechten maternalen Proteindiäten zeigte eine 'Programmierung' des Genoms der Nachkommenschaft in Abhängigkeit von Diät, Gewebe und ontogenetischem Stadium. Die Diät-abhängigen transkriptionellen Regulationen in den Nachkommen umfassten Änderungen des Lipidmetabolismus, der Zellzyklusregulation, des Energiemetabolismus, des organismischen und zellulären Wachstums sowie des Glukokortikoidrezeptor Signalweges. Es wurden keine Gene gefunden, die in allen untersuchten ontogenetischen Stadien eine differentielle Auslenkung zwischen den Diätgruppen aufwiesen. Die transkriptionelle Auslenkung in den HP und LP Nachkommen wurde als molekulares Äquivalent einer Entwicklungsplastizität interpretiert, welche für die Adaptation und den Erhalt des rassetypischen Phänotyps sorgt und daneben Signalwege der Energieausnutzung beeinflusst. Offensichtlich garantiert die 'Fetale Programmierung' des Genoms ein rassespezifisches Wachstum, welches mit einer Prädisposition für metabolische Störungen bis zum Erwachsenenalter einhergeht

Paradoxical signaling regulates structural plasticity in dendritic spines

Transient spine enlargement (3-5 min timescale) is an important event associated with the structural plasticity of dendritic spines. Many of the molecular mechanisms associated with transient spine enlargement have been identified experimentally. Here, we use a systems biology approach to construct a mathematical model of biochemical signaling and actin-mediated transient spine expansion in response to calcium-influx due to NMDA receptor activation. We have identified that a key feature of this signaling network is the paradoxical signaling loop. Paradoxical components act bifunctionally in signaling networks and their role is to control both the activation and inhibition of a desired response function (protein activity or spine volume). Using ordinary differential equation (ODE)-based modeling, we show that the dynamics of different regulators of transient spine expansion including CaMKII, RhoA, and Cdc42 and the spine volume can be described using paradoxical signaling loops. Our model is able to capture the experimentally observed dynamics of transient spine volume. Furthermore, we show that actin remodeling events provide a robustness to spine volume dynamics. We also generate experimentally testable predictions about the role of different components and parameters of the network on spine dynamics

Sr-isotope analysis of speleothems by LA-MC-ICP-MS: High temporal resolution and fast data acquisition

Speleothems are well established climate archives. A wide array of geochemical proxies, including stable isotopes and trace elements are present within speleothems to reconstruct past climate variability. However, each proxy is influenced by multiple factors, often hampering robust interpretation. Sr isotope ratios (87Sr/86Sr) can provide useful information about water residence time and water mixing in the host rock, as they are not fractionated during calcite precipitation. Laser ablation multi-collector-inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) has rarely been used for determination of Sr isotope signatures in speleothems, as speleothems often do not possess appropriately high concentrations of Sr to facilitate this analysis. Yet the advantages of this approach include rapid data acquisition, higher spatial resolution, larger sample throughput and the absence of chemical treatment prior to analysis. We present LA-MC-ICP-MS Sr isotope data from two speleothems from Morocco (Grotte de Piste) and India (Mawmluh Cave), and we compare linescan and spot analysis ablation techniques along speleothem growth axes. The analytical uncertainty of our LA-MC-ICP-MS Sr data is comparable to studies conducted on other carbonate materials. The results of both ablation techniques are reproducible within analytical error, implying that this technique yields robust results when applied to speleothems. In addition, several comparative measurements of different carbonate reference materials (i.e. MACS-3, JCt-1, JCp-1), including tests with standard bracketing and comparison of the 87Sr/86Sr ratios with a nanosecond laser ablation system and a state-of-the-art femtosecond laser ablation system, highlight the robustness of the method

A High Protein Diet during Pregnancy Affects Hepatic Gene Expression of Energy Sensing Pathways along Ontogenesis in a Porcine Model

In rodent models and in humans the impact of gestational diets on the offspring's phenotype was shown experimentally and epidemiologically. The underlying programming of fetal development was shown to be associated with an increased risk of degenerative diseases in adulthood, including the metabolic syndrome. There are clues that diet-dependent modifications of the metabolism during fetal life can persist until adulthood. This leads to the hypothesis that the offspring's transcriptomes show short-term and long-term changes depending on the maternal diet. To this end pregnant German landrace gilts were fed either a high protein diet (HP, 30% CP) or an adequate protein diet (AP, 12% CP) throughout pregnancy. Hepatic transcriptome profiles of the offspring were analyzed at prenatal (94 dpc) and postnatal stages (1, 28, 188 dpn). Depending on the gestational dietary exposure, mRNA expression levels of genes related to energy metabolism, N-metabolism, growth factor signaling pathways, lipid metabolism, nucleic acid metabolism and stress/immune response were affected either in a short-term or in a long-term manner. Gene expression profiles at fetal stage 94 dpc were almost unchanged between the diets. The gestational HP diet affected the hepatic expression profiles at prenatal and postnatal stages. The effects encompassed a modulation of the genome in terms of an altered responsiveness of energy and nutrient sensing pathways. Differential expression of genes related to energy production and nutrient utilization contribute to the maintenance of development and growth performance within physiological norms, however the modulation of these pathways may be accompanied by a predisposition for metabolic disturbances up to adult stages

A low protein diet during pregnancy provokes a lasting shift of hepatic expression of genes related to cell cycle throughout ontogenesis in a porcine model

<p>Abstract</p> <p>Background</p> <p>In rodent models and in humans the impact of gestational diets on the offspring's phenotype was shown experimentally and epidemiologically. Adverse environmental conditions during fetal development provoke an intrauterine adaptive response termed 'fetal programming', which may lead to both persistently biased responsiveness to extrinsic factors and permanent consequences for the organismal phenotype. This leads to the hypothesis that the offspring's transcriptome exhibits short-term and long-term changes, depending on the maternal diet. In order to contribute to a comprehensive inventory of genes and functional networks that are targets of nutritional programming initiated during fetal life, we applied whole-genome microarrays for expression profiling in a longitudinal experimental design covering prenatal, perinatal, juvenile, and adult ontogenetic stages in a porcine model. Pregnant sows were fed either a gestational low protein diet (LP, 6% CP) or an adequate protein diet (AP, 12% CP). All offspring was nursed by foster sows receiving standard diets. After weaning, all offspring was fed standard diets <it>ad libitum</it>.</p> <p>Results</p> <p>Analyses of the hepatic gene expression of the offspring at prenatal (94 <it>dies post conceptionem</it>, dpc) and postnatal stages (1, 28, 188 <it>dies post natum</it>, dpn) included comparisons between dietary groups within stages as well as comparisons between ontogenetic stages within diets to separate diet-specific transcriptional changes and maturation processes. We observed differential expression of genes related to lipid metabolism (e.g. Fatty acid metabolism, Biosynthesis of steroids, Synthesis and degradation of ketone bodies, FA elongation in mitochondria, Bile acid synthesis) and cell cycle regulation (e.g. Mitotic roles of PLK, G1/S checkpoint regulation, G2/M DNA damage checkpoint regulation). Notably, at stage 1 dpn no regulation of a distinct pathway was found in LP offspring.</p> <p>Conclusions</p> <p>The transcriptomic modulations point to persistent functional demand on the liver towards cell proliferation in the LP group but not in the AP group at identical nutritional conditions during postnatal life due to divergent 'programming' of the genome. Together with the observation that the offspring of both groups did not differ in body weight but in body composition and fat content, the data indicate that the activity of various genes led to diverse partitioning of nutrients among peripheral and visceral organs and tissues.</p

Association of Digoxin With Interstage Mortality: Results From the Pediatric Heart Network Single Ventricle Reconstruction Trial Public Use Dataset

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139107/1/jah31279.pd

Chlorophylls of the c family: absolute configuration and inhibition of NADPH:protochlorophyllide oxidoreductase

AbstractUsing circular dichroism (CD) spectroscopy, the stereochemistry at C-132 of members of the chlorophyll (Chl) c family, namely Chls c1, c2, c3 and [8-vinyl]-protochlorophyllide a (Pchlide a) was determined. By comparison with spectra of known enantiomers, all Chl c members turned out to have the (R) configuration, which is in agreement with considerations drawn from chlorophyll biosynthesis. Except for a double bond in the side chain at C-17, the chemical structure of Chl c1 is identical with Pchlide a, the natural substrate of the light-dependent NADPH:protochlorophyllide oxidoreductase (POR). Thus, lack of binding to the active site due to the wrong configuration at C-132, which had been proposed previously, cannot be an explanation for inactivity of Chl c in this enzymic reaction. Our results show rather that Chl c1 is a competitive inhibitor for this enzyme, tested with Pchlide a and Zn-protopheophorbide a (Zn-Ppheide a) as substrates

Analysis of meat quality traits and gene expression profiling of pigs divergent in residual feed intake

peer-reviewedResidual feed intake (RFI), the difference between actual feed intake and predicted feed requirements, is suggested to impact various aspects of meat quality. The objective of this study was to investigate the molecular mechanisms underpinning the relationship between RFI and meat quality. Technological, sensory and nutritional analysis as well as transcriptome profiling were carried out in Longissimus thoracis et lumborum muscle of pigs divergent in RFI (n = 20). Significant differences in sensory profile and texture suggest a minor impairment of meat quality in more efficient pigs. Low RFI animals had leaner carcasses, greater muscle content and altered fatty acid profiles compared to high RFI animals. Accordingly, differentially expressed genes were enriched in muscle growth and lipid & connective tissue metabolism. Differences in protein synthesis and degradation suggest a greater turnover of low RFI muscle, while divergence in connective tissue adhesion may impact tenderness. Fatty acid oxidation tending towards decrease could possibly contribute to reduced mitochondrial activity in low RFI muscle