scholarly journals PPAR-Gamma Activation May Inhibit the In Vivo Degeneration of Bioprosthetic Aortic and Aortic Valve Grafts under Diabetic Conditions

2021 ◽  
Vol 22 (20) ◽  
pp. 11081
Author(s):  
Shintaro Katahira ◽  
Yukiharu Sugimura ◽  
Sophia Grupp ◽  
Robin Doepp ◽  
Jessica Isabel Selig ◽  
...  

Background: We aimed to examine the anti-calcification and anti-inflammatory effects of pioglitazone as a PPAR-gamma agonist on bioprosthetic-valve-bearing aortic grafts in a rat model of diabetes mellitus (DM). Methods: DM was induced in male Wistar rats by high-fat diet with an intraperitoneal streptozotocin (STZ) injection. The experimental group received additional pioglitazone, and controls received normal chow without STZ (n = 20 each group). Cryopreserved aortic donor grafts including the aortic valve were analyzed after 4 weeks and 12 weeks in vivo for analysis of calcific bioprosthetic degeneration. Results: DM led to a significant media proliferation at 4 weeks. The additional administration of pioglitazone significantly increased circulating adiponectin levels and significantly reduced media thickness at 4 and 12 weeks, respectively (p = 0.0002 and p = 0.0107, respectively). Graft media calcification was highly significantly inhibited by pioglitazone after 12 weeks (p = 0.0079). Gene-expression analysis revealed a significant reduction in relevant chondro-osteogenic markers osteopontin and RUNX-2 by pioglitazone at 4 weeks. Conclusions: Under diabetic conditions, pioglitazone leads to elevated circulating levels of adiponectin and to an inhibition of bioprosthetic graft degeneration, including lower expression of chondro-osteogenic genes, decreased media proliferation, and inhibited graft calcification in a small-animal model of DM.

2012 ◽  
Vol 302 (5) ◽  
pp. E532-E539 ◽  
Author(s):  
Haihong Zong ◽  
Michal Armoni ◽  
Chava Harel ◽  
Eddy Karnieli ◽  
Jeffrey E. Pessin

Conventional (whole body) CYP2E1 knockout mice displayed protection against high-fat diet-induced weight gain, obesity, and hyperlipidemia with increased energy expenditure despite normal food intake and spontaneous locomotor activity. In addition, the CYP2E1 knockout mice displayed a marked improvement in glucose tolerance on both normal chow and high-fat diets. Euglycemic-hyperinsulinemic clamps demonstrated a marked protection against high-fat diet-induced insulin resistance in CYP2E1 knockout mice, with enhanced adipose tissue glucose uptake and insulin suppression of hepatic glucose output. In parallel, adipose tissue was protected against high-fat diet-induced proinflammatory cytokine production. Taken together, these data demonstrate that the CYP2E1 deletion protects mice against high-fat diet-induced insulin resistance with improved glucose homeostasis in vivo.


2013 ◽  
Vol 305 (10) ◽  
pp. H1530-H1537 ◽  
Author(s):  
Belinda H. McCully ◽  
Wohaib Hasan ◽  
Cole T. Streiff ◽  
Jennifer C. Houle ◽  
William R. Woodward ◽  
...  

Obesity increases the risk of arrhythmias and sudden cardiac death, but the mechanisms are unknown. This study tested the hypothesis that obesity-induced cardiac sympathetic outgrowth and hyperinnervation promotes the development of arrhythmic events. Male Sprague-Dawley rats (250–275 g), fed a high-fat diet (33% kcal/fat), diverged into obesity-resistant (OR) and obesity-prone (OP) groups and were compared with rats fed normal chow (13% kcal/fat; CON). In vitro experiments showed that both OR and OP rats exhibited hyperinnervation of the heart and high sympathetic outgrowth compared with CON rats, even though OR rats are not obese. Despite the hyperinnervation and outgrowth, we showed that, in vivo, OR rats were less susceptible to arrhythmic events after an intravenous epinephrine challenge compared with OP rats. On examining total and stimulus-evoked neurotransmitter levels in an ex vivo system, we demonstrate that atrial acetylcholine content and release were attenuated in OP compared with OR and CON groups. OP rats also expressed elevated atrial norepinephrine content, while norepinephrine release was suppressed. These findings suggest that the consumption of a high-fat diet, even in the absence of overt obesity, stimulates sympathetic outgrowth and hyperinnervation of the heart. However, normalized cardiac parasympathetic nervous system control may protect the heart from arrhythmic events.


Nutrients ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 880 ◽  
Author(s):  
Mónica Sánchez-Tapia ◽  
Jonathan Martínez-Medina ◽  
Armando R Tovar ◽  
Nimbe Torres

It is difficult to know if the cause for obesity is the type of sweetener, high fat (HF) content, or the combination of sweetener and fat. The purpose of the present work was to study different types of sweeteners; in particular, steviol glycosides (SG), glucose, fructose, sucrose, brown sugar, honey, SG + sucrose (SV), and sucralose on the functionality of the adipocyte. Male Wistar rats were fed for four months with different sweeteners or sweetener with HF added. Taste receptors T1R2 and T1R3 were differentially expressed in the tongue and intestine by sweeteners and HF. The combination of fat and sweetener showed an additive effect on circulating levels of GIP and GLP-1 except for honey, SG, and brown sugar. In adipose tissue, sucrose and sucralose stimulated TLR4, and c-Jun N-terminal (JNK). The combination of HF with sweeteners increased NFκB, with the exception of SG and honey. Honey kept the insulin signaling pathway active and the smallest adipocytes in white (WAT) and brown (BAT) adipose tissue and the highest expression of adiponectin, PPARγ, and UCP-1 in BAT. The addition of HF reduced mitochondrial branched-chain amino transferase (BCAT2) branched-chain keto acid dehydrogenase E1 (BCKDH) and increased branched chain amino acids (BCAA) levels by sucrose and sucralose. Our data suggests that the consumption of particular honey maintained functional adipocytes despite the consumption of a HF diet.


Author(s):  
Marco Giammanco ◽  
Stefania Aiello ◽  
Alessandra Casuccio ◽  
Maurizio La Guardia ◽  
Luca Cicero ◽  
...  

Experimental studies have highlighted that the administration of 3,5-diiodo-L-thyronine (T2) to rats fed diets rich in lipids induces a decrease of cholesterol and triglycerides plasma levels and body weight (BW) without inducing liver steatosis. On the basis of these observations we carried out some experimental <em>in vivo</em> studies to assess the effects of multiple high doses of T2 on the pituitary thyroid axis of rats fed diet rich in lipids. Fifteen male Wistar rats were divided into three groups of five animals each. The first group (N group) received standard diet, the second group was fed with a high fat diet (HFD group), while the third group (HFDT2 group) was additionally given T2 intraperitoneally at a dose level of 70 µg/100 g of BW three times a week up to four weeks. At the end of the treatment, blood sample from each animal was collected, centrifuged and the serum was stored at -20°C. The serum concentrations of thyroidstimulating hormone (TSH), triiodothyronine, thyroxine, adrenocorticotropic hormone, triglycerides, cholesterol, glucose, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase were then determined. In addition, liver of rats was examined by histology in order to assess the presence and degree of steatosis. The administration of T2 to rats fed with a high fat diet suppressed TSH secretion (P=0.013) while no steatosis was observed in the liver of these animals. Our data show that multiple administrations of high doses of T2 to rats fed diets rich in lipid inhibit TSH secretion and prevent the onset of liver steatosis in these animals.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Sheng-Lung Hsu ◽  
Hsien-Hui Chung ◽  
I-Hung Chen ◽  
Yat-Ching Tong

Objective. To investigate the change of loperamide-induced prostate relaxation in rats fed with high-fat diet (HFD).Materials and Methods. Adult male Wistar rats were divided into 2 groups: (1) control rats fed with normal chow and (2) rats fed with HFD for 6 months. The prostate was removed for histology study. Isolated prostate strips were hung in organ bath and precontracted with 1 μmol/L phenylephrine or 50 mmol/L KCl. The relaxation responses to loperamide 0.1 to 10 μmol/L were recorded. Western blotting analyses were performed for prostateμ-opioid receptors (MOR) and ATP-sensitive potassium (KATP) channel proteins: sulfonylurea receptor (SUR) and inwardly rectifying potassium channel (Kir) 6.2 subunits.Results. Body weight, prostate weight, plasma levels of glucose, insulin, triglyceride, and cholesterol, as well as systolic blood pressure, were significantly increased in the HFD rats. Histology showed prostatic hyperplasia in the HFD rat prostate. Prostatic relaxation induced by loperamide was markedly reduced in HFD when compared to the control. Protein expressions of MOR, SUR, and Kir 6.2 were decreased in HFD-fed rats.Conclusion. Loperamide-induced prostate relaxation is decreased in HFD rats due to reduced MOR andKATPchannel expressions.


Diabetologia ◽  
2020 ◽  
Vol 64 (1) ◽  
pp. 129-141
Author(s):  
Marie-Sophie Nguyen-Tu ◽  
Aida Martinez-Sanchez ◽  
Isabelle Leclerc ◽  
Guy A. Rutter ◽  
Gabriela da Silva Xavier

Abstract Aims/hypothesis Transcription factor 7-like 2 (TCF7L2) is a downstream effector of the Wnt/β-catenin signalling pathway implicated in type 2 diabetes risk through genome-wide association studies. Although its expression is critical for adipocyte development, the potential roles of changes in adipose tissue TCF7L2 levels in diabetes risk are poorly defined. Here, we investigated whether forced changes in Tcf7l2 expression in adipocytes affect whole body glucose or lipid metabolism and crosstalk between disease-relevant tissues. Methods Tcf7l2 was selectively ablated in mature adipocytes in C57BL/6J mice using Cre recombinase under Adipoq promoter control to recombine Tcf7l2 alleles floxed at exon 1 (referred to as aTCF7L2 mice). aTCF7L2 mice were fed normal chow or a high-fat diet for 12 weeks. Glucose and insulin sensitivity, as well as beta cell function, were assessed in vivo and in vitro. Levels of circulating NEFA, selected hormones and adipokines were measured using standard assays. Results Reduced TCF7L2 expression in adipocytes altered glucose tolerance and insulin secretion in male but not in female mice. Thus, on a normal chow diet, male heterozygote knockout mice (aTCF7L2het) exhibited impaired glucose tolerance at 16 weeks (p = 0.03) and increased fat mass (1.4 ± 0.1-fold, p = 0.007) but no changes in insulin secretion. In contrast, male homozygote knockout (aTCF7L2hom) mice displayed normal body weight but impaired oral glucose tolerance at 16 weeks (p = 0.0001). These changes were mechanistically associated with impaired in vitro glucose-stimulated insulin secretion (decreased 0.5 ± 0.1-fold vs control mice, p = 0.02) and decreased levels of the incretins glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide (0.6 ± 0.1-fold and 0.4 ± 0.1-fold vs control mice, p = 0.04 and p < 0.0001, respectively). Circulating levels of plasma NEFA and fatty acid binding protein 4 were increased by 1.3 ± 0.1-fold and 1.8 ± 0.3-fold vs control mice (p = 0.03 and p = 0.05, respectively). Following exposure to a high-fat diet for 12 weeks, male aTCF7L2hom mice exhibited reduced in vivo glucose-stimulated insulin secretion (0.5 ± 0.1-fold vs control mice, p = 0.02). Conclusions/interpretation Loss of Tcf7l2 gene expression selectively in adipocytes leads to a sexually dimorphic phenotype, with impairments not only in adipocytes, but also in pancreatic islet and enteroendocrine cells in male mice only. Our findings suggest novel roles for adipokines and incretins in the effects of diabetes-associated variants in TCF7L2, and further illuminate the roles of TCF7L2 in glucose homeostasis and diabetes risk.


2020 ◽  
Vol 17 (2) ◽  
pp. 192
Author(s):  
RONALDO LAU ◽  
SULISTIANA PRABOWO ◽  
RIAMI RIAMI

<p align="justify"><strong>ABSTRACT</strong><strong></strong></p><p align="justify"><strong>Background</strong>: High fat diet increase the absorption of lipid in the intestinum, that can lead to increase LDL cholesterol level in the blood. Sea grapes extract (<em>Caulerpa racemosa</em>) contains antioxidant polyphenolic group that can reduce MTP and ACAT-2 in the body that can decrease LDL cholesterol level in the blood.The purpose of this study is to know the effect of sea grapes extract  on decreasing LDL cholesterol of white male Wistar rats (<em>Rattus norvegicus</em>) fed with high fat diet.</p><p align="justify"><strong>Method</strong>:  24 white male Wistar rats, that divided into 3 groups: 1) group of rats fed with standard diet for 28 days; 2) group of rats fed with high fat diet for 28 days; 3) group of rats fed with high fat diet for 28 days and given 10 gram/kg body weight/day of sea grapes extract on 15<sup>th</sup>-28<sup>th</sup> days. Then the blood LDL cholesterol level measured on the 29<sup>th</sup> day.</p><p align="justify"><strong>Result :</strong> One-Way ANOVA Test showed there was significant difference (p=0.004) of LDL level between the group of rats fed with standard diet (12.37 mg/dl) compared to group of rats fed with high fat diet (17.87 mg/dl). There was significant difference (p=0.001) of LDL level between the group of rats fed with high fat diet (17.87 mg/dl) compared to group of rats fed with high fat diet and sea grapes extract (10.12 mg/dl).</p><p align="justify"><strong>Conclusion: </strong>high fat diet significantly increase blood LDL cholesterol level and sea grapes extract (<em>Caulerpa racemosa</em>) significantly decrease blood LDL cholesterol level.</p><p align="justify"> </p><p align="justify"><strong>Keywords :</strong>Sea grapes extract, LDL cholesterol, high fat diet</p>


2019 ◽  
Vol 70 (6) ◽  
pp. 1983-1987
Author(s):  
Cristian Trambitas ◽  
Anca Maria Pop ◽  
Alina Dia Trambitas Miron ◽  
Dorin Constantin Dorobantu ◽  
Flaviu Tabaran ◽  
...  

Large bone defects are a medical concern as these are often unable to heal spontaneously, based on the host bone repair mechanisms. In their treatment, bone tissue engineering techniques represent a promising approach by providing a guide for osseous regeneration. As bioactive glasses proved to have osteoconductive and osteoinductive properties, the aim of our study was to evaluate by histologic examination, the differences in the healing of critical-sized calvarial bone defects filled with bioactive glass combined with adipose-derived mesenchymal stem cells, compared to negative controls. We used 16 male Wistar rats subjected to a specific protocol based on which 2 calvarial bone defects were created in each animal, one was filled with Bon Alive S53P4 bioactive glass and adipose-derived stem cells and the other one was considered control. At intervals of one week during the following month, the animals were euthanized and the specimens from bone defects were histologically examined and compared. The results showed that this biomaterial was biocompatible and the first signs of osseous healing appeared in the third week. Bone Alive S53P4 bioactive glass could be an excellent bone substitute, reducing the need of bone grafts.


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