Maternal obesity during pregnancy and lactation influences offspring obesogenic adipogenesis but not developmental adipogenesis in mice

Obesity is an escalating health crisis of pandemic proportions and by all accounts it has yet to reach its peak. Growing evidence suggests that obesity may have its origins in utero. Recent studies have shown that maternal obesity during pregnancy may promote adipogenesis in offspring. However, these studies were largely based on cell culture models. Whether or not maternal obesity impacts on offspring adipogenesis in vivo remains to be fully established. Furthermore, in vivo adipogenic differentiation has been shown to happen at distinct time periods, one during development (developmental adipogenesis—which is complete by 4 weeks of age in mice) and another in adulthood in response to feeding a high-fat (HF) diet (obesogenic adipogenesis). We therefore set out to determine whether maternal obesity impacted on offspring adipocyte hyperplasia in vivo and whether maternal obesity impacted on developmental or obesogenic adipogenesis, or both. Our findings reveal that maternal obesity is associated with enhanced obesogenic adipogenesis in HF-fed offspring. Interestingly, in newly weaned (4-week-old) offspring, maternal obesity is associated with adipocyte hypertrophy, but there were no changes in adipocyte number. Our results suggest that maternal obesity impacts on offspring obesogenic adipogenesis but does not affect developmental adipogenesis

Identification of robust cardiac reference genes in a mouse model of cardiometabolic disease

Cardiovascular disease is linked to obesity, the metabolic syndrome, and altered 24hour (circadian) rhythms. Although the underlying mechanisms remain undefined, transcriptome analysis in the heart is beginning to provide important insights into the cardiometabolic pathogenesis. The reliability and accuracy of real-time quantitative PCR generated gene expression data is largely dependent on the selection of suitable reference genes (RG), which must be constitutively expressed regardless of cardio-metabolic disease state and time of day. However, many studies do not employ the appropriate selections strategies. In this study we determined the expression stability of seven candidate RGs (GAPDH, YWHAZ, B2M, EIF4A2, ATP5?, ACTB and CYC1) in a mouse model of diet-induced metabolic syndrome in both the day and night, using geNorm qBasePLUS software. RG expression varied in hearts of normal fed versus high fat fed mice, and was also dependant on the time of day. When all experimental variables were considered YWHAZ and ACTB were ranked the most stable and therefore the most suitable genes for generating comparative gene expression data in heart tissue from murine models of cardiometabolic disease. This study provides important information for reference gene selection, and will aid further transcriptome investigations into heart organ functio

Sensitivity of housekeeping genes in the hypothalamus to mismatch in diets between pre- and postnatal periods in mice

Housekeeping genes are used as internal controls in gene expression studies, but their expression levels vary according to tissue types and experimental treatments. A nutritional mismatch between pre- and postnatal periods, wherein the in utero nutritional environment is suboptimal and post-weaning diet is rich in fat, results in altered hypothalamic expression levels of genes that regulate the offspring's physiology, metabolism and behavior. The present study investigated hypothalamic expression of the housekeeping genes glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-actin and 18s ribosomal RNA (18s rRNA) in offspring subjected to this pre- and postnatal dietary mismatch. Pregnant MF1 mice were fed standard chow (C, 18% casein) or protein restricted (PR, 9% casein) diet throughout pregnancy. Weaned offspring were fed to adulthood a high fat (HF, 45% kcal fat) or chow (21% kcal fat) diet to generate the C/HF, C/C, PR/HF and PR/C groups. Hypothalamic and cerebral cortex tissues were collected from these offspring at 16 weeks of age and analyzed for gene transcript levels by quantitative real time PCR. Hypothalamic GAPDH mRNA levels were higher in PR/HF male and female offspring vs. all other groups (p<0.001 in males). Conversely, hypothalamic beta-actin and 18s rRNA levels were similar in all treatment groups and sex. In the cerebral cortex, GAPDH and beta-actin levels were similar in all groups and sex. The result suggests that beta-actin and 18s rRNA are suitable internal controls for gene expression studies in the hypothalamus, while the stability of GAPDH is compromised, under the condition of a nutritional mismatch between pre- and postnatal period

Statin treatment in hypercholesterolemic pregnant mice reduces cardiovascular risk factors in their offspring

Increasing evidence suggests that hypercholesterolemia during pregnancy initiates pathogenic events in the fetus leading to increased risk of cardiovascular disease in the adult offspring. In this study we examined in mice whether pharmacological intervention using statins in late pregnancy could alleviate the detrimental effects of a high-fat, high-cholesterol (45% fat) maternal diet on the health of the dams and their offspring. Pregnant C57 mice on high-fat, high-cholesterol diet were given the 3hydroxy3methylglutaryl-coenzyme A reductase inhibitor pravastatin in the drinking water (5 mg/kg of body weight per day) in the second half of pregnancy and during lactation to lower cholesterol and improve postweaning maternal blood pressure. Weaned offspring were then fed the high-fat, high-cholesterol diet until adulthood (generating dam/offspring dietary groups high-fat, high-cholesterol/high-fat, high-cholesterol and high-fat, high-cholesterol plus pravastatin during the second half of pregnancy and lactation/high-fat, high-cholesterol). These groups were compared with offspring from mothers fed standard chow (control), which were then fed control diet to adulthood (control/control). Compared with high-fat, high-cholesterol, high-fat, high-cholesterol plus pravastatin during second half of pregnancy and lactation dams showed significantly reduced total cholesterol concentrations and reduced systolic blood pressure. The high-fat, high-cholesterol plus pravastatin during second half of pregnancy and lactation/high-fat, high-cholesterol offspring were significantly lighter, less hypertensive, and more active compared with the high-fat, high-cholesterol/high-fat, high-cholesterol group. Total serum and low-density lipoprotein cholesterol concentrations were significantly lower, and high-density lipoprotein cholesterol concentrations were raised in high-fat, high-cholesterol plus pravastatin during the second half of pregnancy and lactation/high-fat, high-cholesterol offspring, compared with the high-fat, high-cholesterol/high-fat, high-cholesterol group. The control/control offspring showed the lowest blood pressure and cholesterol levels. These findings indicate that the cholesterol-lowering effect of statins in pregnant dams consuming a high-fat, high-cholesterol diet leads to reduced cardiovascular risk factors in offspring that are sustained into adulthood

Effect of maternal protein restriction during pregnancy and postweaning high-fat feeding of diet-induced thermogenesis in adult mouse offspring

Purpose Prenatal undernutrition followed by postweaning feeding of a high-fat diet results in obesity in the adult offspring. In this study, we investigated whether diet-induced thermogenesis is altered as a result of such nutritional mismatch. Methods Female MF-1 mice were fed a normal protein (NP, 18 % casein) or a protein-restricted (PR, 9 % casein) diet throughout pregnancy and lactation. After weaning, male offspring of both groups were fed either a high-fat diet (HF; 45 % kcal fat) or standard chow (C, 7 % kcal fat) to generate the NP/C, NP/HF, PR/C and PR/HF adult offspring groups (n = 7–11 per group). Results PR/C and NP/C offspring have similar body weights at 30 weeks of age. Postweaning HF feeding resulted in significantly heavier NP/HF offspring (P < 0.01), but not in PR/HF offspring, compared with their chow-fed counterparts. However, the PR/HF offspring exhibited greater adiposity (P < 0.01) v the NP/HF group. The NP/HF offspring had increased energy expenditure and increased mRNA expression of uncoupling protein-1 and β-3 adrenergic receptor in the interscapular brown adipose tissue (iBAT) compared with the NP/C mice (both at P < 0.01). No such differences in energy expenditure and iBAT gene expression were observed between the PR/HF and PR/C offspring. Conclusions These data suggest that a mismatch between maternal diet during pregnancy and lactation, and the postweaning diet of the offspring, can attenuate diet-induced thermogenesis in the iBAT, resulting in the development of obesity in adulthood

A high fat "Western-style" diet induces AMD-like features in Wildtype mice

Scope: The intake of a “Western-style” diet rich in fats is linked with developing retinopathies including age-related macular degeneration (AMD). Wildtype mice are given a high fat diet (HFD) to determine how unhealthy foods can bring about retinal degeneration. Methods and results: Following weaning, female C57BL/6 mice are maintained on standard chow (7% kcal fat, n = 29) or a HFD (45% kcal fat, n = 27) for 12 months. Animals were sacrificed following electroretinography (ERG) and their eyes analyzed by histology, confocal immunofluorescence, and transmission electron microscopy. HFD mice become obese, but showed normal retinal function compared to chow-fed controls. However, diminished β3tubulin labeling of retinal cross-sections indicated fewer/damaged neuronal processes in the inner plexiform layer. AMD-linked proteins clusterin and TIMP3 accumulated in the retinal pigment epithelium (RPE) and Bruch's membrane (BrM). Neutral lipids also deposited in the outer retinae of HFD mice. Ultrastructural analysis revealed disorganized photoreceptor outer segments, collapsed/misaligned RPE microvilli, vacuoles, convoluted basolateral RPE infolds and BrM changes. Basal laminar-like deposits were also present alongside abnormal choroidal endothelial cells. Conclusions: We show that prolonged exposure to an unhealthy “Western-style” diet alone can recapitulate early-intermediate AMD-like features in wildtype mice, highlighting the importance of diet and nutrition in the etiology of sight-loss.</p

Photoperiodic regulation of leptin resistance in the seasonally breeding Siberian hamster (Phodopus sungorus)

Seasonal Siberian hamsters lose fat reserves, decrease body weight and leptin concentrations, and suppress reproduction on short-day photoperiod (SD). Chronic leptin infusion at physiological doses caused body weight and fat loss in SD animals but was ineffective in long-day (LD) hamsters. Using ovariectomized estrogen-treated females, we tested the hypothesis that responsiveness to leptin is regulated by photoperiod. On SD, hypothalamic neuropeptide Y, agouti-related peptide, and cocaine- and amphetamine-regulated transcript gene expression in the arcuate nucleus did not exhibit significant changes, and despite SD-induced fat loss, the catabolic peptide proopiomelanocortin was down-regulated. Food restriction of LD-housed animals caused significant reduction of fat reserves and serum leptin concentrations to SD levels, suppressed serum gonadotropins, and induced increased anabolic (neuropeptide Y, agouti-related peptide) and decreased catabolic (proopiomelanocortin, cocaine- and amphetamine-regulated transcript) gene expression in the arcuate nucleus. Leptin infusion in food-restricted animals had no effect on fat reserves or gonadotropins and did not modulate neuropeptide gene expression. Also, leptin treatment did not blunt the refeeding responses or weight and fat gain in LD-housed food-restricted animals. In conclusion, our results strongly suggest that hypothalamic responses to leptin are regulated primarily by photoperiod, rather than seasonal changes in fat reserves, sex steroids, or leptin concentrations.<br/

Combination therapy using potassium channels openers and nifedipine in human myometrium in vitro

The influence of the pregnancy hormone progesterone on macrophage activation is well studied due to the existence of macrophages within the female reproductive tract and uterus during pregnancy. The production of nitric oxide (NO) from L-arginine, occurs via the action of the enzyme nitric oxide synthase-2 (NOS2) and can be induced experimentally by LPS. Progesterone downregulates NO production through binding the glucocorticoid receptor, in order to limit infl ammation. Arginase I also uses L-arginine as a substrate resulting in the production of L-ornithine and urea as a by-product. Induction of arginase I is typically associated with stimulation with the Th2 associated cytokines IL-4 and IL-13. The aim of this work was to investigate the ability of progesterone to modulate arginase gene expression and enzyme activity in murine macrophages