scholarly journals Overcompensation of CoA Trapping by Di(2-ethylhexyl) Phthalate (DEHP) Metabolites in Livers of Wistar Rats

2021 ◽  
Vol 22 (24) ◽  
pp. 13489
Author(s):  
David Hala ◽  
Lene H. Petersen ◽  
Duane B. Huggett ◽  
Michelle A. Puchowicz ◽  
Henri Brunengraber ◽  
...  

Di(2-ethylhexyl) phthalate (DEHP) is commonly used as a plasticizer in various industrial and household plastic products, ensuring widespread human exposures. Its routine detection in human bio-fluids and the propensity of its monoester metabolite to activate peroxisome proliferator activated receptor-α (PPARα) and perturb lipid metabolism implicate it as a metabolic disrupter. In this study we evaluated the effects of DEHP exposure on hepatic levels of free CoA and various CoA esters, while also confirming the metabolic activation to CoA esters and partial β-oxidation of a DEHP metabolite (2-ethyhexanol). Male Wistar rats were exposed via diet to 2% (w/w) DEHP for fourteen-days, following which hepatic levels of free CoA and various CoA esters were identified using liquid chromatography-mass spectrometry. DEHP exposed rats showed significantly elevated free CoA and increased levels of physiological, DEHP-derived and unidentified CoA esters. The physiological CoA ester of malonyl-CoA and DEHP-derived CoA ester of 3-keto-2-ethylhexanoyl-CoA were the most highly elevated, at eighteen- and ninety eight-times respectively. We also detected sixteen unidentified CoA esters which may be derivative of DEHP metabolism or induction of other intermediary metabolism metabolites. Our results demonstrate that DEHP is a metabolic disrupter which affects production and sequestration of CoA, an essential cofactor of oxidative and biosynthetic reactions.

Author(s):  
Soundarya Priyadharsini K. ◽  
Nirmala P. ◽  
Ashok Kumar P. ◽  
Krishna Prasad T.

Background: Hyperlipidemia is a well known risk factor for cardiovascular disease, especially atherosclerotic coronary artery disease. Peroxisome proliferator activated receptor α (PPARα), a member of this nuclear receptor family, has emerged as an important player in this scenario, with evidence supporting a central co-ordinated role in the regulation of fatty acid oxidation, lipid and lipoprotein metabolism and inflammatory and vascular responses, all of which would be predicted to reduce atherosclerotic risk. The low-density lipoprotein (LDL) receptor (LDLR) is the primary pathway for removal of cholesterol from the circulation, and its activity is meticulously governed by intracellular cholesterol levels. Hence in this study we investigated the effect of Lutein on PPARα and LDLR expression in liver of wistar rats.Methods: Male Wistar rats were divided into 6 groups of 6 each. Group I served as control. Group II III, IV, V and VI rats were received high cholesterol diet. Group III was treated with Atorvastatin 5mg/kg. Group IV, V and VI rats were treated with 25mg/kg, 50mg/kg and 100mg/kg of Lutein. After 16 weeks, liver tissue samples were collected from all the groups of animals to evaluate the expression of PPARα and LDLR.Results: The expression of Peroxisome proliferator activated receptor α and low-density lipoprotein (LDL) receptor (LDLR) was significantly increased in Lutein treated hypercholesterolemic male wistar rats.Conclusions: The results of this study indicate that Lutein activates LDL receptor and PPARα in hypercholesterolemic male wistar rats.


2021 ◽  
pp. 56-69
Author(s):  
Derya Köseoğlu ◽  
Gülnur Take ◽  
Banu Aktaş Yılmaz ◽  
Erdal Kan ◽  
Nuri Çakır

Background: Osteoporosis is a metabolic skeletal disease with low bone mass and bone microarchitectural disorganization. Thiazolidinediones (TZD) increase insulin sensitivity through activation of peroxisome proliferator-activated receptor gamma (PPARγ). One of the most important side effects of this drugs is its effects on bone, especially in postmenopausal women. The purpose of this study was to evaluate the effect of diabetes mellitus (DM), insulin, and TZDs on bone in postmenopausal Wistar rats. Methods: Sixteen postmenopausal Wistar rats were divided into four groups: (i) control group, (ii) Streptozotocin-induced DM group without treatment, (iii) Streptozotocin-induced DM group with insulin therapy, and (iv) Streptozotocin-induced DM group receiving rosiglitazone. Pictures of the obtained samples were taken under computer-equipped photo-light microscope, and bone tissue ratios were calculated in an area of 1 mm2. In this area, trabecular thicknesses were measured from six randomly selected regions. In addition, femoral neck regions were determined by measuring the farthest distance. Results: Compared to the control group, trabecular thicknesses were decreased in the uncontrolled DM and rosiglitazone groups. In the rosiglitazone-treated group, trabecular thickness was decreased compared to the uncontrolled DM group. The histological examination of the bones showed that uncontrolled DM and rosiglitazone treatment negatively affected the osteoblast and osteocyte activity. Insulin-treated group had a similar histologic examination compared to the control group. Conclusion: Our study showed that DM had unfavorable effects on bones, and rosiglitazone further exerts this effect. However, the negative effect of DM may be neutralized with the use of insulin. Keywords: diabetes mellitus, bone, osteoporosis, bone histomorphometry, rosiglitazone, insulin, thiazolidinediones


2001 ◽  
Vol 277 (6) ◽  
pp. 4098-4103 ◽  
Author(s):  
Fiona M. Campbell ◽  
Ray Kozak ◽  
Alese Wagner ◽  
Judith Y. Altarejos ◽  
Jason R. B. Dyck ◽  
...  

2015 ◽  
Vol 35 (2) ◽  
pp. 755-766 ◽  
Author(s):  
Agnieszka Mikłosz ◽  
Bartłomiej Łukaszuk ◽  
Adrian Chabowski ◽  
Filip Rogowski ◽  
Krzysztof Kurek ◽  
...  

Background: Thyroid hormones (THs) are key regulators of cardiac physiology as well as modulators of different cellular signals including the sphingomyelin/ceramide pathway. The objective of this study was to examine the effect of hyperthyroidism on the metabolism of sphingolipids in the muscle heart. Methods: Male Wistar rats were treated for 10 days with triiodothyronine (T3) at a dose of 50µg/100g of body weight. Animals were then anaesthetized and samples of the left ventricle were excised. Results: We have demonstrated that prolonged, in vivo, T3 treatment increased the content of sphinganine (SFA), sphingosine (SFO), ceramide (CER) and sphingomyelin (SM), but decreased the level of sphingosine-1-phosphate (S1P) in cardiac muscle. Accordingly, the changes in sphingolipids content were accompanied by a lesser activity of neutral sphingomyelinase and without significant changes in ceramidases activity. Hyperthyroidism also induced activation of AMP-activated protein kinase (AMPK) with subsequently increased expression of mitochondrial proteins: cytochrome c oxidase IV (COX IV), β-hydroxyacyl-CoA dehydrogenase (β-HAD), carnityne palmitoyltransferase I (CPT I) and nuclear peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α). Conclusions: We conclude that prolonged T3 treatment increases sphingolipids metabolism which is reflected by higher concentration of SFA and CER in heart muscle. Furthermore, hyperthyroidism-induced increase in heart sphingomyelin (SM) concentration might be one of the mechanisms underlying maintenance of CER at relatively low level by its conversion to SM together with decreased S1P content.


Author(s):  
Karilyn E. Sant ◽  
Hadley M. Moreau ◽  
Larissa M. Williams ◽  
Haydee M. Jacobs ◽  
Anna M. Bowsher ◽  
...  

Abstract Mono-2-ethylhexyl phthalate (MEHP) is the primary metabolite of the ubiquitous plasticizer and toxicant, di-2-ethylhexyl phthalate. MEHP exposure has been linked to abnormal development, increased oxidative stress, and metabolic syndrome in vertebrates. Nuclear factor, Erythroid 2 Like 2 (Nrf2), is a transcription factor that regulates gene expression in response to oxidative stress. We investigated the role of Nrf2a in larval steatosis following embryonic exposure to MEHP. Wild-type and nrf2a mutant (m) zebrafish embryos were exposed to 0 or 200 μg/l MEHP from 6 to either 96 (histology) or 120 hours post fertilization (hpf). At 120 hpf, exposures were ceased and fish were maintained in clean conditions until 15 days post fertilization (dpf). At 15 dpf, fish lengths and lipid content were examined, and the expression of genes involved in the antioxidant response and lipid processing was quantified. At 96 hpf, a subset of animals treated with MEHP had vacuolization in the liver. At 15 dpf, deficient Nrf2a signaling attenuated fish length by 7.7%. MEHP exposure increased hepatic steatosis and increased expression of peroxisome proliferator-activated receptor alpha target fabp1a1. Cumulatively, these data indicate that developmental exposure alone to MEHP may increase risk for hepatic steatosis and that Nrf2a does not play a major role in this phenotype.


2019 ◽  
Vol 127 (2) ◽  
pp. 027003 ◽  
Author(s):  
Hussein Shoaito ◽  
Julia Petit ◽  
Audrey Chissey ◽  
Nicolas Auzeil ◽  
Jean Guibourdenche ◽  
...  

2009 ◽  
Vol 296 (5) ◽  
pp. E1120-E1132 ◽  
Author(s):  
Christelle Veyrat-Durebex ◽  
Xavier Montet ◽  
Manlio Vinciguerra ◽  
Asllan Gjinovci ◽  
Paolo Meda ◽  
...  

The inbred Lou/C rat, originating from the Wistar strain, has been described as a model of resistance to diet-induced obesity, but little is known about its metabolism. Since this knowledge could provide some clues about the etiology of obesity/insulin resistance, this study aimed at characterizing glucose and lipid metabolism in Lou/C vs. Wistar rats. This was achieved by performing glucose and insulin tolerance tests, euglycemic hyperinsulinemic clamps, and characterization of intracellular insulin signaling in skeletal muscle. Substrate-induced insulin secretion was evaluated using perfused pancreas and isolated islets. Finally, body fat composition and the expression of various factors involved in lipid metabolism were determined. Body weight and caloric intake were lower in Lou/C than in Wistar rats, whereas food efficiency was similar. Improved glucose tolerance of Lou/C rats was not related to increased insulin output but was related to improved insulin sensitivity/responsiveness in the liver and in skeletal muscles. In the latter tissue, this was accompanied by improved insulin signaling, as suggested by higher activation of the insulin receptor and of the Akt/protein kinase B pathway. Fat deposition was markedly lower in Lou/C than in Wistar rats, especially in visceral adipose tissue. In the inguinal adipose depot, expression of uncoupling protein-1 was detected in Lou/C but not in Wistar rats, in keeping with a higher expression of peroxisome proliferator-activated receptor-γ coactivator-1 in these animals. The Lou/C rat is a valuable model of spontaneous food restriction with associated improved insulin sensitivity. Independently from its reduced caloric intake, it also exhibits a preferential channeling of nutrients toward utilization rather than storage.


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