scholarly journals Curcumin promotes AApoAII amyloidosis and peroxisome proliferation in mice by activating the PPARα signaling pathway

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Jian Dai ◽  
Ying Li ◽  
Fuyuki Kametani ◽  
Xiaoran Cui ◽  
Yuichi Igarashi ◽  
...  

Curcumin is a polyphenol compound that exhibits multiple physiological activities. To elucidate the mechanisms by which curcumin affects systemic amyloidosis, we investigated amyloid deposition and molecular changes in a mouse model of amyloid apolipoprotein A-II (AApoAII) amyloidosis, in which mice were fed a curcumin-supplemented diet. Curcumin supplementation for 12 weeks significantly increased AApoAII amyloid deposition relative to controls, especially in the liver and spleen. Liver weights and plasma ApoA-II and high-density lipoprotein concentrations were significantly elevated in curcumin-supplemented groups. RNA-sequence analysis revealed that curcumin intake affected hepatic lipid metabolism via the peroxisome proliferator-activated receptor (PPAR) pathway, especially PPARα activation, resulting in increased Apoa2 mRNA expression. The increase in liver weights was due to activation of PPARα and peroxisome proliferation. Taken together, these results demonstrate that curcumin is a PPARα activator and may affect expression levels of proteins involved in amyloid deposition to influence amyloidosis and metabolism in a complex manner.

2020 ◽  
Author(s):  
Jian Dai ◽  
Ying Li ◽  
Fuyuki Kametani ◽  
Xiaoran Cui ◽  
Yuichi Igarashi ◽  
...  

AbstractCurcumin is a polyphenol compound that exhibits multiple physiological activities. To elucidate the mechanisms by which curcumin affects systemic amyloidosis, we investigated amyloid deposition and molecular changes in a mouse model of amyloid apolipoprotein A-II (AApoAII) amyloidosis, in which mice were fed a curcumin-supplemented diet. Curcumin supplementation for 12 weeks significantly increased AApoAII amyloid deposition relative to controls, especially in the liver and spleen. Liver weights and plasma ApoA-II and high-density lipoprotein concentrations were significantly elevated in curcumin-supplemented groups. RNA-sequence analysis revealed that curcumin intake affected hepatic lipid metabolism via the peroxisome proliferator-activated receptor (PPAR) pathway, especially PPARα activation, resulting in increased Apoa2 mRNA expression. The increase in liver weights was due to activation of PPARα and peroxisome proliferation. Taken together, these results demonstrate that curcumin is a PPARα activator and may affect expression levels of proteins involved in amyloid deposition to influence amyloidosis and metabolism in a complex manner.


2007 ◽  
Vol 293 (1) ◽  
pp. R70-R77 ◽  
Author(s):  
Sebastian Luci ◽  
Beatrice Giemsa ◽  
Holger Kluge ◽  
Klaus Eder

This study investigated the effect of clofibrate treatment on expression of target genes of peroxisome proliferator-activated receptor (PPAR)-α and various genes of the lipid metabolism in liver and adipose tissue of pigs. An experiment with 18 pigs was performed in which pigs were fed either a control diet or the same diet supplemented with 5 g clofibrate/kg for 28 days. Pigs treated with clofibrate had heavier livers, moderately increased mRNA concentrations of various PPAR-α target genes in liver and adipose tissue, a higher concentration of 3-hydroxybutyrate, and markedly lower concentrations of triglycerides and cholesterol in plasma and lipoproteins than control pigs ( P < 0.05). mRNA concentrations of sterol regulatory element-binding proteins (SREBP)-1 and -2, insulin-induced genes ( Insig) -1 and Insig-2, and the SREBP target genes acetyl-CoA carboxylase, 3-methyl-3-hydroxyglutaryl-CoA reductase, and low-density lipoprotein receptor in liver and adipose tissue and mRNA concentrations of apolipoproteins A-I, A-II, and C-III in the liver were not different between both groups of pigs. In conclusion, this study shows that clofibrate treatment activates PPAR-α in liver and adipose tissue and has a strong hypotriglyceridemic and hypocholesterolemic effect in pigs. The finding that mRNA concentrations of some proteins responsible for the hypolipidemic action of fibrates in humans were not altered suggests that there were certain differences in the mode of action compared with humans. It is also shown that PPAR-α activation by clofibrate does not affect hepatic expression of SREBP target genes involved in synthesis of triglycerides and cholesterol homeostasis in liver and adipose tissue of pigs.


2001 ◽  
Vol 354 (1) ◽  
pp. 225-232 ◽  
Author(s):  
Delphine HOURTON ◽  
Philippe DELERIVE ◽  
Jana STANKOVA ◽  
Bart STAELS ◽  
M. John CHAPMAN ◽  
...  

Regulation of the expression of platelet-activating factor (PAF) receptor by atherogenic lipoproteins might contribute to atherogenesis. We show that progressive oxidation of low-density lipoprotein (LDL) gradually inhibits PAF receptor expression on the macrophage cell surface. We tested the effect of oxidized LDL (oxLDL) on PAF receptor expression in human monocytes that do not contain peroxisome-proliferator-activated receptor γ (PPARγ), a nuclear receptor activated by oxLDL. OxLDL decreased by 50% (P ⩽0.001) and by 29% (P⩽0.05) the binding of PAF and the expression of PAF receptor mRNA respectively. Next we demonstrated that progressive oxidation of LDLs significantly activated PPARα-dependent transcription in transfected mouse aortic endothelial cells. Finally we demonstrated, in mature macrophages, that fenofibrate (20µM), a specific PPARα agonist, but not the specific PPARγ agonist BRL49653 (20nM), significantly decreased both PAF binding and PAF receptor mRNA expression, by 65% and 40% (P⩽0.001) respectively. Additionally, another PPARα agonist, Wy14,643, decreased PAF receptor promoter activity by 70% (P⩽0.05) in transfected THP-1 cells, suggesting the involvement of the proximal promoter region (-980 to -500) containing a series of four nuclear factor (NF)-κB motifs. Thus PPARα might be involved in the down-regulation of PAF receptor gene expression by oxLDLs in human monocytes/macrophages. The oxidation of one or more lipid components of LDLs might result in the formation of natural activators of PPARα. It is hypothesized that such activators might modulate inflammation and apoptosis upon atherogenesis by decreasing the expression of PAF receptor.


Animals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 7 ◽  
Author(s):  
Fardos Hassan ◽  
Elshimaa Roushdy ◽  
Asmaa Kishawy ◽  
Asmaa Zaglool ◽  
Hammed Tukur ◽  
...  

The effects of rutin on growth performance, hematological and biochemical profiles, antioxidant capacity, economics and the relative expression of selected antioxidants and lipid-related genes were studied in broiler chickens over 42 days. A total of 200 one-day-old female Ross-308 broiler chickens were distributed into four groups, with five replicates of 10 individuals per replicate. They were fed with 0 (control), 0.25, 0.5 or 1 g rutin/kg supplementation in their basal diet. Dietary rutin supplementation, especially the 1 g/kg diet, increased body weight gain, the protein efficiency ratio (p < 0.001) and both white blood cell and lymphocyte counts (p < 0.001). However, it had no effect on total protein, albumin, globulin, or alanine transaminase. A high concentration of rutin (0.5 and 1 g/kg) also significantly reduced serum total cholesterol, triacylglycerol and low-density lipoprotein cholesterol concentrations (p < 0.001), as well as malondialdehyde concentrations (p = 0.001). A high concentration diet also increased the activity of superoxide dismutase, catalase and glutathione peroxidase. Of the lipid-related genes examined, acetyl CoA carboxylase and fatty acid synthase were significantly down-regulated in the livers of rutin-fed individuals, whereas carnitine palmitoyl transferase 1 and peroxisome proliferator-activated receptor alpha were significantly up-regulated. Therefore, rutin supplementation at 1 g/kg has the potential to improve the productive performance and health status of broiler chickens.


2021 ◽  
Vol 49 (11) ◽  
pp. 030006052110550
Author(s):  
Xing Wang ◽  
Shuchun Chen ◽  
Dan Lv ◽  
Zelin Li ◽  
Luping Ren ◽  
...  

Objective To investigate the effect of liraglutide on the browning of white fat and the suppression of obesity via regulating microRNA (miR)-27b in vivo and in vitro. Methods Sprague-Dawley rats were fed a high-fat (HF) diet and 3T3-L1 pre-adipocytes were differentiated into mature white adipocytes. Rats and mature adipocytes were then treated with different doses of liraglutide. The mRNA and protein levels of browning-associated proteins, including uncoupling protein 1 (UCP1), PR domain containing 16 (PRDM16), CCAAT enhancer binding protein β (CEBPβ), cell death-inducing DFFA-like effector A (CIDEA) and peroxisome proliferator-activated receptor-γ-coactivator 1α (PGC-1α), were detected using quantitative real-time polymerase chain reaction and Western blotting. Results Liraglutide decreased body weight and reduced the levels of blood glucose, triglyceride and low-density lipoprotein cholesterol in HF diet-fed rats. Liraglutide increased the levels of UCP1, PRDM16, CEBPβ, CIDEA and PGC-1α in vivo and vitro. The levels of miR-27b were upregulated in HF diet-fed rats, whereas liraglutide reduced the levels of miR-27b. In vitro, overexpression of miR-27b decreased the mRNA and protein levels of UCP1, PRDM16, CEBPβ, CIDEA and PGC-1α. Transfection with the miR-27b mimics attenuated the effect of liraglutide on the browning of white adipocytes. Conclusion Liraglutide induced browning of white adipose through regulation of miR-27b.


Nutrients ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 280 ◽  
Author(s):  
Anne-Marie Lundsgaard ◽  
Andreas M. Fritzen ◽  
Bente Kiens

It is well recognized that whole-body fatty acid (FA) oxidation remains increased for several hours following aerobic endurance exercise, even despite carbohydrate intake. However, the mechanisms involved herein have hitherto not been subject to a thorough evaluation. In immediate and early recovery (0–4 h), plasma FA availability is high, which seems mainly to be a result of hormonal factors and increased adipose tissue blood flow. The increased circulating availability of adipose-derived FA, coupled with FA from lipoprotein lipase (LPL)-derived very-low density lipoprotein (VLDL)-triacylglycerol (TG) hydrolysis in skeletal muscle capillaries and hydrolysis of TG within the muscle together act as substrates for the increased mitochondrial FA oxidation post-exercise. Within the skeletal muscle cells, increased reliance on FA oxidation likely results from enhanced FA uptake into the mitochondria through the carnitine palmitoyltransferase (CPT) 1 reaction, and concomitant AMP-activated protein kinase (AMPK)-mediated pyruvate dehydrogenase (PDH) inhibition of glucose oxidation. Together this allows glucose taken up by the skeletal muscles to be directed towards the resynthesis of glycogen. Besides being oxidized, FAs also seem to be crucial signaling molecules for peroxisome proliferator-activated receptor (PPAR) signaling post-exercise, and thus for induction of the exercise-induced FA oxidative gene adaptation program in skeletal muscle following exercise. Collectively, a high FA turnover in recovery seems essential to regain whole-body substrate homeostasis.


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