scholarly journals The differential effects of the timing of maternal nutrient restriction in the ovine placenta on glucocorticoid sensitivity, uncoupling protein 2, peroxisome proliferator-activated receptor-γ and cell proliferation

Reproduction ◽  
2009 ◽  
Vol 138 (3) ◽  
pp. 601-608 ◽  
Author(s):  
M Yiallourides ◽  
S P Sebert ◽  
V Wilson ◽  
D Sharkey ◽  
S M Rhind ◽  
...  

Nutrient restriction (NR) during critical windows of pregnancy has differential effects on placento-fetal growth and development. Our study, therefore, investigated developmental and metabolic adaptations within the ovine placenta following NR at different critical windows during the first 110 days of gestation (term=147 days). Thus, the effects of NR on cell proliferation, glucocorticoid sensitivity, IGF1 and 2 receptor, peroxisome proliferator-activated receptor γ (PPARG), and uncoupling protein (UCP)2 gene expression in the placenta were examined. Singleton bearing sheep (n=4–8 per group) were fed either 100% of their total metabolizable energy requirements throughout the study or 50% of this amount between 0–30, 31–65, 66–110, and 0–110 days gestation. A significant reduction in cell proliferation and increased gene expression for the glucocorticoid and IGF2 receptors, PPARG, and UCP2 were detected in placentae sampled from mothers who were nutrient restricted between days 66 and 110 of gestation, only, relative to controls. This window of gestation coincides with the maximum placental growth and the start of exponential growth of the fetus when there are substantially increased metabolic demands on the placenta compared with earlier in gestation. Consequently, increased glucocorticoid sensitivity and suppressed IGF2 action could contribute to a switch in the placenta from proliferation to differentiation, thereby improving its nutrient transfer capacity. Upregulation of PPARG and UCP2 would promote placental fatty acid metabolism thereby limiting glucose utilization. These compensatory placental responses may serve to maintain fetal growth but could result in adverse adaptations such as the early onset of the metabolic syndrome in later life.

Endocrinology ◽  
2006 ◽  
Vol 147 (10) ◽  
pp. 4695-4704 ◽  
Author(s):  
Neus Pedraza ◽  
Meritxell Rosell ◽  
Joan Villarroya ◽  
Roser Iglesias ◽  
Frank J. Gonzalez ◽  
...  

Uncoupling protein-3 (UCP3) is a member of the mitochondrial carrier family expressed preferentially in skeletal muscle and heart. It appears to be involved in metabolic handling of fatty acids in a way that minimizes excessive production of reactive oxygen species. Fatty acids are powerful regulators of UCP3 gene transcription. We have found that the role of peroxisome proliferator-activated receptor-α (PPARα) on the control of UCP3 gene expression depends on the tissue and developmental stage. In adults, UCP3 mRNA expression is unaltered in skeletal muscle from PPARα-null mice both in basal conditions and under the stimulus of starvation. In contrast, UCP3 mRNA is down-regulated in adult heart both in fed and fasted PPARα-null mice. This occurs despite the increased levels of free fatty acids caused by fasting in PPARα-null mice. In neonates, PPARα-null mice show impaired UCP3 mRNA expression in skeletal muscle in response to milk intake, and this is not a result of reduced free fatty acid levels. The murine UCP3 promoter is activated by fatty acids through either PPARα or PPARδ but not by PPARγ or retinoid X receptor alone. PPARδ-dependent activation could be a potential compensatory mechanism to ensure appropriate expression of UCP3 gene in adult skeletal muscle in the absence of PPARα. However, among transcripts from other PPARα and PPARδ target genes, only those acutely induced by milk intake in wild-type neonates were altered in muscle or heart from PPARα-null neonates. Thus, PPARα-dependent regulation is required for appropriate gene regulation of UCP3 as part of the subset of fatty-acid-responsive genes in neonatal muscle and heart.


2020 ◽  
Vol 10 (2) ◽  
pp. 106-117
Author(s):  
Maryam Mostafavian ◽  
◽  
Ahmad Abdi ◽  
Javad Mehrabani ◽  
Alireza Barari ◽  
...  

Objective: Decreased physical activity coupled with increased High‐Fat Diet (HFD) intake prompts obesity. Current research suggests that changing White Adipose Tissue (WAT) to brown promotes energy expenditure to counter obesity. The purpose of this study was to investigate the effects of aerobic Progressive training and Capsaicin (Cap) on Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and Uncoupling protein-1 (UPC-1) gene expression in rat fed a high-fat diet. Methods: 40 male Wistar rats aged 8-12 weeks, were fed a Normal Diet (ND) (n=8) or HFD (n=32) for 8 weeks. After 8 weeks, rats were divided into 5 groups: ND, HFD, High-Fat Diet-Training (HFDT), High-Fat Diet-Capsaicin (HFDCap), high-fat diet-training-capsaicin (HFDTCap). Training groups have performed a progressive aerobic running program on a motor-driven treadmill for eight weeks. Capsaicin (4 mg/kg/day) were administered orally, by gavage, once a day. PGC-1α and UCP-1 gene expression levels in the VAT were measured by Real-time PCR method. Results: The results of this study showed that PGC-1α and UCP-expression was decreased in HFD group compared to ND group. Also, the expression of PGC-1α and UPC-1 in HFDT, HFDCap and HFDTCap groups was significantly increased compared to HFD. The expression of PGC-1α and UPC-1 in HFDTCap was also significantly increased compared to HFDT and HFDCap groups. Conclusion: Possibly, eight weeks of progressive training combined with capsaicin administration has an effect on the browning of visceral adipose tissue in HFD rats by increasing expression of PGC-1α and UCP-1.


2005 ◽  
Vol 389 (1) ◽  
pp. 47-56 ◽  
Author(s):  
M. Carmen CARMONA ◽  
Elayne HONDARES ◽  
M. Luisa RODRÍGUEZ DE LA CONCEPCIÓN ◽  
Víctor RODRÍGUEZ-SUREDA ◽  
Julia PEINADO-ONSURBE ◽  
...  

C/EBPβ (CCAAT/enhancer-binding protein β) is a transcriptional regulator of the UCP1 (uncoupling protein-1) gene, the specific marker gene of brown adipocytes that is responsible for their thermogenic capacity. To investigate the role of C/EBPβ in brown fat, we studied the C/EBPβ-null mice. When placed in the cold, C/EBPβ−/− mice did not maintain body temperature. This cold-sensitive phenotype occurred, although UCP1 and PGC-1α (peroxisome-proliferator-activated receptor γ co-activator-1α) gene expression was unaltered in brown fat of C/EBPβ−/− mice. The UCP1 gene promoter was repressed by the truncated inhibitory C/EBPβ isoform LIP (liver-enriched transcriptional inhibitory protein, the truncated inhibitory C/EBPβ isoform). Since C/EBPβ-null mice lack both C/EBPβ isoforms, active LAP (liver-enriched transcriptional activatory protein, the active C/EBPβ isoform) and LIP, the absence of LIP may have a stronger effect than the absence of LAP upon UCP1 gene expression. Gene expression for UCP2 and UCP3 was not impaired in all tissues analysed. In primary brown adipocytes from C/EBPβ−/− mice, induction of gene expression by noradrenaline was preserved. In contrast, the expression of genes related to lipid storage was impaired, as was the amount of triacylglycerol mobilized after acute cold exposure in brown fat from C/EBPβ−/− mice. LPL (lipoprotein lipase) activity was also impaired in brown fat, but not in other tissues of C/EBPβ−/− mice. LPL protein levels were also diminished, but this effect was independent of changes in LPL mRNA, suggesting that C/EBPβ is involved in the post-transcriptional regulation of LPL gene expression in brown fat. In summary, defective thermoregulation owing to the lack of C/EBPβ is associated with the reduced capacity to supply fatty acids as fuels to sustain brown fat thermogenesis.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 340-340
Author(s):  
Murase Yuko ◽  
Fesseha Meseret ◽  
Abbaspour Nazanin ◽  
Young Hong Mee

Abstract Objectives Watermelon is high in L-citrulline, a precursor for L-arginine, which in turn may reduce the risk of colorectal cancer (CRC). Research has shown that L-arginine inhibits the hyperproliferation of colorectal tumor cells as a marker for CRC. The objective of this study was, therefore, to examine the effects of watermelon powder supplementation on colonic cell proliferation and their gene expression. The hypothesis was that watermelon powder supplementation would reduce CRC risk by regulating colonic expression of genes related to epithelial cell proliferation. Methods Thirty-two 21-day-old, male, Sprague Dawley rats were randomly assigned to one of the following isocaloric diets: 0.5% watermelon powder, 0.36% L-arginine, and control for 9 weeks. All animals were injected with azoxymethane (15 mg/kg body weight). Colonic cell proliferation was measured using ki-67 immunohistochemistry, and colonic gene expression was determined using a quantitative real-time polymerase chain reaction (PCR). Results Both watermelon powder and L-arginine groups exhibited lower proliferating index (P = 0.041) and lower proliferative zone (P = 0.041). In addition, watermelon powder and L-arginine supplementation upregulated p21Waf1/Cip1 gene expression (P = 0.048). There were no significant differences in the expression of Cyclin D1, Cyclin-dependent kinase 2 (CDK2), Cyclin-dependent kinase 4 (CDK4), and Peroxisome proliferator-activated receptor γ (PPARγ). Conclusions These results suggest that watermelon or L-arginine supplementation may decrease the risk of CRC as they both reduced proliferation by upregulating a cyclin-dependent kinase inhibitor. Additional markers for gene expression involving cell proliferation are needed to confirm the present findings. Funding Sources National Watermelon Promotion Board (NWPB 15–16) National Cancer Institutes of Health (U54CA132384 for SDSU and U54132379 for UCSD).


2015 ◽  
Vol 36 (6) ◽  
pp. 2466-2479 ◽  
Author(s):  
XiaoLe Xu ◽  
Mengzi He ◽  
Tingting Liu ◽  
Yi Zeng ◽  
Wei Zhang

Background/Aims: salusin-ß is considered to be a potential pro-atherosclerotic factor. Regulation and function of vascular smooth muscle cells (VSMCs) are important in the progression of atherosclerosis. Peroxisome proliferator-activated receptor gamma (PPARγ) exerts a vascular protective role beyond its metabolic effects. Salusin-ß has direct effects on VSMCs. The aim of the present study was to assess the effect of salusin-ß on PPARγ gene expression in primary cultured rat VSMCs. Methods: Western blotting analysis, real-time PCR and transient transfection approach were used to determine expression of target proteins. Specific protein knockdown was performed with siRNA transfection. Cell proliferation was determined by 5-bromo-2'-deoxyuridine incorporation. The levels of inflammation indicators interleukin-6 (IL-6) and tumor necrosis factor-a (TNF-a) were determined using enzyme-linked immunosorbent assay. Results: Salusin-ß negatively regulated PPARγ gene expression at protein, mRNA and gene promoter level in VSMCs. The inhibitory effect of salusin-ß on PPARγ gene expression contributed to salusin-ß-induced VSMCs proliferation and inflammation in vitro. IγBa-NF-γB activation, but not NF-γB p50 or p65, mediated the salusin-ß-induced inhibition of PPARγ gene expression. Salusin-ß induced nuclear translocation of histone deacetylase 3 (HDAC3). HDAC3 siRNA prevented salusin-ß-induced PPARγ reduction. Nuclear translocation of HDAC3 in response to salusin-ß was significantly reversed by an IγBa inhibitor BAY 11-7085. Furthermore, IγBa-HDAC3 complex was present in the cytosol of VSMCs but interrupted after salusin-ß treatment. Conclusion: IγBa-HDAC3 pathway may contribute to salusin-ß-induced inhibition of PPARγ gene expression in VSMCs.


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