Contribution of Large Animals to Translational Research on Prenatal Programming of Obesity and Associated Diseases.

BACKGROUND: The awareness of factors causing obesity and associated disorders has grown up in the last years from genome to a more complicated concept (developmental programming) in which prenatal and early-postnatal conditions markedly modify the phenotype and homeostasis of the individuals and determine juvenile growth, life-time fitness/obesity and disease risks. METHOD: Experimentation in human beings is impeded by ethical issues plus inherent high variability and confounding factors (genetics, lifestyle and socioeconomic heterogeneity) and preclinical studies in adequate translational animal models are therefore decisive. Most of the studies have been performed in rodents, whilst the use of large animals is scarce. Having in mind body-size, handlingeasiness and cost-efficiency, the main large animal species for use in biomedical research are rabbits, sheep and swine. The choice of the model depends on the research objectives. AIMS: To outline the main features of the use of rabbits, sheep and swine and their contributions as translational models in prenatal programming of obesity and associated disorders.

Prenatal Nicotine Exposure Augments Renal Oxidative Stress in Embryos of Pregnant Rats with Reduced Uterine Perfusion Pressure.

BACKGROUND/AIM: Both maternal nicotine (NIC) exposure and placental insufficiency increase oxidative stress in the fetal kidney ensuing fetal programming of renal diseases in adult life. Their combined effects, however, are unknown. We tested the hypothesis that maternal NIC exposure exacerbates renal oxidative stress and injury in fetuses of pregnant rats with placental insufficiency. MATERIALS AND METHODS: Fourteen-day-pregnant rats were subjected to sham operation or reduced uterine perfusion pressure (RUPP) that received either nicotine (20 µg/ml in 1% saccharine) or vehicle (1% saccharine) in their drinking water. At gestational age of 21 days, male fetuses were collected by C-section and sacrificed: plasma and renal cotinine content, extent of renal oxidative stress (4-hydroxynonenal [HNE] and HO-1) and injury (KIM-1) were determined together with the weight of the fetal kidney and fetus. RESULTS: Prenatal NIC exposure resulted in cotinine accumulation in the plasma and kidney of the fetuses, augmented RUPP-associated increase in renal HNE content and HO-1 expression as well as KIM-1 expression. NIC also enhanced RUPP-induced reduction in fetal and fetal kidney weight. CONCLUSION: Prenatal NIC exposure augments the existing renal risk in the growth-restricted fetus, which may contribute to worsening in fetal programming of renal disease.

Maternal fructose drives placental uric acid production leading to adverse fetal outcomes.

Maternal metabolic diseases increase offspring risk for low birth weight and cardiometabolic diseases in adulthood. Excess fructose consumption may confer metabolic risks for both women and their offspring. However, the direct consequences of fructose intake per se are unknown. We assessed the impact of a maternal high-fructose diet on the fetal-placental unit in mice in the absence of metabolic syndrome and determined the association between maternal serum fructose and placental uric acid levels in humans. In mice, maternal fructose consumption led to placental inefficiency, fetal growth restriction, elevated fetal serum glucose and triglyceride levels. In the placenta, fructose induced de novo uric acid synthesis by activating the activities of the enzymes AMP deaminase and xanthine oxidase. Moreover, the placentas had increased lipids and altered expression of genes that control oxidative stress. Treatment of mothers with the xanthine oxidase inhibitor allopurinol reduced placental uric acid levels, prevented placental inefficiency, and improved fetal weights and serum triglycerides. Finally, in 18 women delivering at term, maternal serum fructose levels significantly correlated with placental uric acid levels. These findings suggest that in mice, excess maternal fructose consumption impairs placental function via a xanthine oxidase/uric acid-dependent mechanism, and similar effects may occur in humans.

Placental involvement by non-Hodgkin lymphoma in a Crohn disease patient on long-term thiopurine therapy.

We report the first published case of aggressive diffuse large B-cell (non-Hodgkin) lymphoma in a 35-year-old pregnant woman who had Crohn disease and was taking long-term thiopurine therapy: the patient developed placental insufficiency, and there was intrauterine fetal death.

Arsenic exposure in pregnant mice disrupts placental vasculogenesis and causes spontaneous abortion.

Arsenic is an abundant toxicant in ground water and soil around areas with extractive industries. Human epidemiological studies have shown that arsenic exposure is linked to developmental defects and miscarriage. The placenta is known to utilize vasculogenesis to develop its circulation. The hypothesis tested here states the following: arsenic exposure causes placental dysmorphogenesis and defective placental vasculogenesis resulting in placental insufficiency and subsequent spontaneous abortion. To test this hypothesis, pregnant mice were exposed to sodium arsenite (AsIII) through drinking water from conception through weanling stages. Neonatal assessment of birth rates, pup weights, and litter sizes in arsenic exposed and control mothers revealed that AsIII-exposed mothers had only 40% the fecundity of controls. Preterm analysis at E12.5 revealed a loss of fecundity at E12.5 from either 20 ppm or greater exposures to AsIII. There was no loss of fecundity at E7.5 suggesting that spontaneous abortion occurs during placentation. Histomorphometry on E12.5 placentae from arsenic-exposed mice revealed placental dysplasia especially in the vasculature. These results suggest that arsenic toxicity is causative for mammalian spontaneous abortion by virtue of aberrant placental vasculogenesis and placental insufficiency.

Effects of Aroclor 1254 on the expression of rat placental PRL-family genes.

This study was performed to investigate the effects of Aroclor 1254 (A1254), a commercial polychlorinated biphenyl mixture, on the expression of rat placental prolactin (PRL) family genes and reproductive activity. Placental lactogen-Iv and -II, and prolactin-like protein-A and -C mRNA levels were significantly decreased in the placentas of A1254-treated rats in a dose-dependent manner. The mRNA levels of Pit-1alpha and beta isotypes, which are involved in the regulation of PRL family gene expression, were also decreased in the A1254-treated rat placenta. In the rat placental junctional zone, high-dose A1254 (25 mg/kg B.W.) treatment reduced the number of spongiotrophoblasts, cells in which the PRL family genes are expressed. Finally, maternal exposure to A1254 was shown to have significant toxic effects on reproductive activity, including embryonic and placental growth retardation, delay of parturition, and reduction of the number of pups per litter. The results of the present study indicated that A1254 has an inhibitory effect on PRL family, Pit-1alpha, and beta gene expression in the rat placenta, leading to significant toxic effects on reproductive activity in rats.

Placental toxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in mice.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a well-known model substance for inducing in humans and monkeys a severe extrapyramidal syndrome similar to Parkinson's disease. The neurotoxic action of MPTP can be exerted not only in adult animals but also during fetal development by diaplacental passage. Here we show that, during the gestation period of mice, the placenta is another important target organ of MPTP cytotoxicity. Pregnant NMRI mice on gestation day 15 received a single intraperitoneal dose of 20, 40, or 60 mg/kg MPTP. Developmental parameters of the fetuses and the placentas were determined on gestation day 18. Placental weight was consistently reduced in all experimental groups. Histology showed conspicuous alterations of the labyrinth layer; at 20 mg/kg MPTP there was already a significant reduction of the trabecular diameters and from 40 mg/kg onwards, severe necrosis of the syncytial trophoblast cells. In addition, there were necrotic alterations of the cells of the visceral yolk sac. The toxic effects are confined to the placenta at the doses used in the present experiments, leading at just 60 mg/kg to a marked placental insufficiency syndrome.

Ethanol-associated selective fetal malnutrition: a contributing factor in the fetal alcohol syndrome.

The pathogenesis of the FAS, particularly the characteristic IUGR, may be due in part to ethanol-related placental injury. Ethanol and/ or acetaldehyde may impair placental transfer of nutrients essential for growth, e.g., amino acids. Such restriction could occur regardless of maternal nutritional status: selective fetal malnutrition. Impairment of placental nutrient transport at critical phases of fetal organogenesis could compound any direct fetotoxic effects of ethanol or acetaldehyde. The effect of ethanol upon human placental hormone synthesis and transport of vitamins, minerals, glucose, and nucleic acid precursors awaits further investigation. Similarly, potential interactions between ethanol and other xenobiotics commonly abused by alcoholics require clarification.

[Beta blockaders and general pathology]. / Bêta-bloquants et pathologie générale

The authors review the literature on the undesirable side effects of beta blockaders (excluding the cardiovascular system) and report the new therapeutic propects in psychiatry and in various metabolic disorders. The necessity of sufficient follow up made us choose propanolol as reference product without neglecting acebutolol, pindolol and oxprenolol.

[Morphometric studies of the human placenta under the influence of sex steroids]. / Morphometrische Untersuchungen der menschlichen Plazenta unter dem Einfluss synthetischer Sexualsteroide.

Placentas of different gestational age from women with oral contraception in the early phase of gravidity were studied morphometrically. An elevated risk for a placental insufficiency could not be found.