scholarly journals Selenate Prevents Adipogenesis through Induction of Selenoprotein S and Attenuation of Endoplasmic Reticulum Stress

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2882 ◽  
Author(s):  
Choon Kim ◽  
Kee-Hong Kim
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Early Stage ◽  
Marker Genes ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Homologous Protein ◽  
Selenoprotein S ◽  
The Individual

The conversion of preadipocytes to adipocytes (adipogenesis) is a potential target to treat or prevent obesity. Selenate, an inorganic form of selenium, elicits diverse health benefits, mainly through its incorporation into selenoproteins. The individual roles of selenium and certain selenoproteins have been reported. However, the effects of selenate treatment on selenoproteins in adipocytes are unclear. In this study, the effects of selenate pretreatment on selenoprotein and endoplasmic reticulum (ER) stress during adipogenesis were examined in vitro. The selenate pretreatment dose-dependently suppressed the adipogenesis of 3T3-L1 preadipocytes. The selenate pretreatment at 50 μM for 24 h almost completely suppressed adipogenesis without cytotoxic effects. The expression of the adipogenic genes peroxisome proliferator-activated receptor gamma, CCAAT-enhancer binding protein alpha, and leptin was suppressed by selenate. This pretreatment also upregulated selenoprotein S (SEPS1), an ER resident selenoprotein that reduces ER stress, and prevented dexamethasone-induced SEPS1 degradation during the early stage of adipogenesis. The selenate-inhibited adipogenesis was associated with an attenuation of ER stress. The expression of the ER stress marker genes was upregulated during the early stage of differentiation, whereas the selenate pretreatment suppressed the mRNA expression of the XBP1 and C/EBP homologous protein. The collective data suggest a preventive role of selenate and SEPS1 in adipogenesis, and support a novel dietary approach to prevent obesity.

scholarly journals Regulation of Adipsin Expression by Endoplasmic Reticulum Stress in Adipocytes

Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 314
Author(s):  
Ka-Young Ryu ◽  
Eon Ju Jeon ◽  
Jaechan Leem ◽  
Jae-Hyung Park ◽  
Hochan Cho
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Peroxisome Proliferator ◽  
Adipose Tissues ◽  
Peroxisome Proliferator Activated Receptor ◽  
Er Stress Response ◽  
Stress Markers ◽  
Transcriptional Reprogramming

Adpsin is an adipokine that stimulates insulin secretion from β-cells and improves glucose tolerance. Its expression has been found to be markedly reduced in obese animals. However, it remains unclear what factors lead to downregulation of adipsin in the context of obesity. Endoplasmic reticulum (ER) stress response is activated in various tissues under obesity-related conditions and can induce transcriptional reprogramming. Therefore, we aimed to investigate the relationship between adipsin expression and ER stress in adipose tissues during obesity. We observed that obese mice exhibited decreased levels of adipsin in adipose tissues and serum and increased ER stress markers in adipose tissues compared to lean mice. We also found that ER stress suppressed adipsin expression via adipocytes-intrinsic mechanisms. Moreover, the ER stress-mediated downregulation of adipsin was at least partially attributed to decreased expression of peroxisome proliferator-activated receptor γ (PPARγ), a key transcription factor in the regulation of adipocyte function. Finally, treatment with chemical chaperones recovered the ER stress-mediated downregulation of adipsin and PPARγ in vivo and in vitro. Our findings suggest that activated ER stress in adipose tissues is an important cause of the suppression of adipsin expression in the context of obesity.

scholarly journals Endoplasmic Reticulum Stress Impaired Uncoupling Protein 1 Expression via the Suppression of Peroxisome Proliferator-Activated Receptor γ Binding Activity in Mice Beige Adipocytes

2019 ◽  
Vol 20 (2) ◽  
pp. 274 ◽  
Author(s):  
Ana Yuliana ◽  
Asumi Daijo ◽  
Huei-Fen Jheng ◽  
Jungin Kwon ◽  
Wataru Nomura ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Uncoupling Protein ◽  
Peroxisome Proliferator ◽  
Uncoupling Protein 1 ◽  
Peroxisome Proliferator Activated Receptor ◽  
Beige Adipocytes ◽  
Ucp1 Expression ◽  
Er Homeostasis

Endoplasmic reticulum (ER) homeostasis is critical in maintaining metabolic regulation. Once it is disrupted due to accumulated unfolded proteins, ER homeostasis is restored via activation of the unfolded protein response (UPR); hence, the UPR affects diverse physiological processes. However, how ER stress influences adipocyte functions is not well known. In this study, we investigated the effect of ER stress in thermogenic capacity of mice beige adipocytes. Here, we show that the expression of uncoupling protein 1 (Ucp1) involved in thermoregulation is severely suppressed under ER stress conditions (afflicted by tunicamycin) in inguinal white adipose tissue (IWAT) both in vitro and in vivo. Further investigation showed that extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) were both activated after ER stress stimulation and regulated the mRNA levels of Ucp1 and peroxisome proliferator-activated receptor γ (Pparγ), which is known as a Ucp1 transcriptional activator, in vitro and ex vivo. We also found that Pparγ protein was significantly degraded, reducing its recruitment to the Ucp1 enhancer, thereby downregulating Ucp1 expression. Additionally, only JNK inhibition, but not ERK, rescued the Pparγ protein. These findings provide novel insights into the regulatory effect of ER stress on Ucp1 expression via Pparγ suppression in beige adipocytes.

Abstract 70: PPARdelta Agonist GW1516 Attenuates Diet-Induced Dyslipidemia, Insulin Resistance and Aortic Inflammation in Ldlr -/- Mice

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Lazar Bojic ◽  
Dawn Telford ◽  
Brian Sutherland ◽  
Cynthia Sawyez ◽  
Jane Edwards ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Er Stress ◽  
Proinflammatory Cytokines ◽  
Map Kinases ◽  
Fasting Blood Glucose ◽  
M2 Macrophage ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Arginase 1

Objective: The peroxisome proliferator-activated receptor (PPAR) delta has been implicated in systemic lipid homeostasis and inflammation. However, the role of PPARdelta agonists as anti-atherogenic agents remains unclear. In the present study, we used low-density lipoprotein receptor-null mice (Ldlr-/-) fed a high fat (HF) diet to test the hypothesis that a selective PPARdelta agonist corrects metabolic dysregulation and attenuates inflammation associated with atherosclerosis. Methods and Results: Ldlr -/- mice were fed chow or HF (42% fat, 0.2% cholesterol) for 4 weeks. Subsequently, the HF group was fed either HF or HF plus GW1516 (3mg/kg/d) for a further 8 weeks. Fasting plasma triglyceride, total cholesterol and free fatty acids were significantly decreased (-50%) by intervention with GW1516. In addition, GW1516 normalized fasting blood glucose and improved glucose and insulin tolerance. GW1516 also enhanced total energy expenditure compared to HF-fed mice. In the aorta, ER-stress markers CHOP and GRP78 were significantly elevated in HF-fed mice, which were markedly attenuated by GW1516-intervention. Aortae of HF-fed mice also showed marked elevations in the expression of proinflammatory cytokines including Ccl3, Il1beta, Icam1, Tnf, Il6 and Ccl2. Furthermore, HF-aortae, compared to chow, displayed reduced expression of the M2 macrophage marker arginase-1(Arg1). Intervention with GW1516 significantly attenuated aortic expression of all examined proinflammatory cytokines, and restored Arg1 expression. Enhanced MAPKerk signalling and decreased AKT/FoxO1 signalling are known to induce inflammatory cytokine expression in vitro. HF-feeding induced phosphorylation (p) of the MAP kinases ERK1/2 and p38 and dampened levels of pAKT and pFoxO1 in the aorta. In contrast, aortae of GW1516-treated animals displayed normalized levels of pERK1/2, p-p38, pAKT and pFoxO1. Conclusions: These studies demonstrate that PPARdelta activation ameliorates dyslipidemia and insulin resistance in HF-fed Ldlr -/- mice. Furthermore, PPARdelta activation inhibits aortic ER-stress as well as dysregulation of MAPK and AKT/FoxO1 signalling induced by HF-feeding, resulting in inhibition of the inflammatory response within the aorta.

scholarly journals Peroxisome Proliferator-Activated Receptor γ Activation Restores Islet Function in Diabetic Mice through Reduction of Endoplasmic Reticulum Stress and Maintenance of Euchromatin Structure

2009 ◽  
Vol 29 (8) ◽  
pp. 2053-2067 ◽  
Author(s):  
Carmella Evans-Molina ◽  
Reiesha D. Robbins ◽  
Tatsuyoshi Kono ◽  
Sarah A. Tersey ◽  
George L. Vestermark ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Molecular Mechanisms ◽  
Serum Insulin ◽  
Peroxisome Proliferator ◽  
Islet Function ◽  
Direct Role ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ppar Γ

ABSTRACT The nuclear receptor peroxisome proliferator-activated receptor γ (PPAR-γ) is an important target in diabetes therapy, but its direct role, if any, in the restoration of islet function has remained controversial. To identify potential molecular mechanisms of PPAR-γ in the islet, we treated diabetic or glucose-intolerant mice with the PPAR-γ agonist pioglitazone or with a control. Treated mice exhibited significantly improved glycemic control, corresponding to increased serum insulin and enhanced glucose-stimulated insulin release and Ca2+ responses from isolated islets in vitro. This improved islet function was at least partially attributed to significant upregulation of the islet genes Irs1, SERCA, Ins1/2, and Glut2 in treated animals. The restoration of the Ins1/2 and Glut2 genes corresponded to a two- to threefold increase in the euchromatin marker histone H3 dimethyl-Lys4 at their respective promoters and was coincident with increased nuclear occupancy of the islet methyltransferase Set7/9. Analysis of diabetic islets in vitro suggested that these effects resulting from the presence of the PPAR-γ agonist may be secondary to improvements in endoplasmic reticulum stress. Consistent with this possibility, incubation of thapsigargin-treated INS-1 β cells with the PPAR-γ agonist resulted in the reduction of endoplasmic reticulum stress and restoration of Pdx1 protein levels and Set7/9 nuclear occupancy. We conclude that PPAR-γ agonists exert a direct effect in diabetic islets to reduce endoplasmic reticulum stress and enhance Pdx1 levels, leading to favorable alterations of the islet gene chromatin architecture.

Constitutive activation of p46JNK2 is indispensable for C/EBPδ induction in the initial stage of adipogenic differentiation

2017 ◽  
Vol 474 (20) ◽  
pp. 3421-3437 ◽  
Author(s):  
Joji Kusuyama ◽  
Tomokazu Ohnishi ◽  
Kenjiro Bandow ◽  
Muhammad Subhan Amir ◽  
Kaori Shima ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Energy Homeostasis ◽  
Early Stage ◽  
Adipogenic Differentiation ◽  
Endocrine System ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Initial Stage

Adipogenic differentiation plays a vital role in energy homeostasis and endocrine system. Several transcription factors, including peroxisome proliferator-activated receptor gamma 2 and CCAAT–enhancer-binding protein (C/EBP) α, β, and δ, are important for the process, whereas the stage-specific intracellular signal transduction regulating the onset of adipogenesis remains enigmatic. Here, we explored the functional role of c-jun N-terminal kinases (JNKs) in adipogenic differentiation using in vitro differentiation models of 3T3-L1 cells and primary adipo-progenitor cells. JNK inactivation with either a pharmacological inhibitor or JNK2-specific siRNA suppressed adipogenic differentiation, characterized by decreased lipid droplet appearance and the down-regulation of Adiponectin, fatty acid protein 4 (Fabp4), Pparg2, and C/ebpa expressions. Conversely, increased adipogenesis was observed by the inducible overexpression of p46JNK2 (JNK2-1), whereas it was not observed by that of p54JNK2 (JNK2-2), indicating a distinct role of p46JNK2. The essential role of JNK appears restricted to the early stage of adipogenic differentiation, as JNK inhibition in the later stages did not influence adipogenesis. Indeed, JNK phosphorylation was significantly induced at the onset of adipogenic differentiation. As for the transcription factors involved in early adipogenesis, JNK inactivation significantly inhibited the induction of C/ebpd, but not C/ebpb, during the initial stage of adipogenic differentiation. JNK activation increased C/ebpd mRNA and protein expression through the induction and phosphorylation of activating transcription factor 2 (ATF2) that binds to a responsive element within the C/ebpd gene promoter region. Taken together, these data indicate that constitutive JNK activity is specifically required for the initial stage differentiation events of adipocytes.

scholarly journals The Human Lipodystrophy Gene Product Berardinelli-Seip Congenital Lipodystrophy 2/Seipin Plays a Key Role in Adipocyte Differentiation

Endocrinology ◽  
2009 ◽  
Vol 150 (10) ◽  
pp. 4552-4561 ◽  
Author(s):  
Weiqin Chen ◽  
Vijay K. Yechoor ◽  
Benny Hung-Junn Chang ◽  
Ming V. Li ◽  
Keith L. March ◽  
...  
Keyword(s):  
Adipocyte Differentiation ◽  
Early Stage ◽  
Short Hairpin Rna ◽  
Peroxisome Proliferator ◽  
Fat Cell ◽  
Hairpin Rna ◽  
Peroxisome Proliferator Activated Receptor ◽  
Morphogenetic Protein ◽  
Short Hairpin

Abstract Mutations in the Berardinelli-Seip congenital lipodystrophy 2 gene (BSCL2) are the underlying defect in patients with congenital generalized lipodystrophy type 2. BSCL2 encodes a protein called seipin, whose function is largely unknown. In this study, we investigated the role of Bscl2 in the regulation of adipocyte differentiation. Bscl2 mRNA is highly up-regulated during standard hormone-induced adipogenesis in 3T3-L1 cells in vitro. However, this up-regulation does not occur during mesenchymal stem cell (C3H10T1/2 cells) commitment to the preadipocyte lineage. Knockdown of Bscl2 by short hairpin RNA in C3H10T1/2 cells has no effect on bone morphogenetic protein-4-induced preadipocyte commitment. However, knockdown in 3T3-L1 cells prevents adipogenesis induced by a standard hormone cocktail, but adipogenesis can be rescued by the addition of peroxisome proliferator-activated receptor-γ agonist pioglitazone at an early stage of differentiation. Interestingly, pioglitazone-induced differentiation in the absence of standard hormone is not associated with up-regulated Bscl2 expression. On the other hand, short hairpin RNA-knockdown of Bscl2 largely blocks pioglitazone-induced adipose differentiation. These experiments suggest that Bscl2 may be essential for normal adipogenesis; it works upstream or at the level of peroxisome proliferator-activated receptor-γ, enabling the latter to exert its full activity during adipogenesis. Loss of Bscl2 function thus interferes with the normal transcriptional cascade of adipogenesis during fat cell differentiation, resulting in near total loss of fat or lipodystrophy.

scholarly journals Roles and Therapeutic Implications of Endoplasmic Reticulum Stress and Oxidative Stress in Cardiovascular Diseases

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1167
Author(s):  
Yan Zhou ◽  
Dharmani Devi Murugan ◽  
Haroon Khan ◽  
Yu Huang ◽  
Wai San Cheang
Keyword(s):  
Oxidative Stress ◽  
Endoplasmic Reticulum ◽  
Cardiovascular Diseases ◽  
Er Stress ◽  
Metabolic Diseases ◽  
Critical Role ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Therapeutic Implications ◽  
And Oxidative Stress

In different pathological states that cause endoplasmic reticulum (ER) calcium depletion, altered glycosylation, nutrient deprivation, oxidative stress, DNA damage or energy perturbation/fluctuations, the protein folding process is disrupted and the ER becomes stressed. Studies in the past decade have demonstrated that ER stress is closely associated with pathogenesis of obesity, insulin resistance and type 2 diabetes. Excess nutrients and inflammatory cytokines associated with metabolic diseases can trigger or worsen ER stress. ER stress plays a critical role in the induction of endothelial dysfunction and atherosclerosis. Signaling pathways including AMP-activated protein kinase and peroxisome proliferator-activated receptor have been identified to regulate ER stress, whilst ER stress contributes to the imbalanced production between nitric oxide (NO) and reactive oxygen species (ROS) causing oxidative stress. Several drugs or herbs have been proved to protect against cardiovascular diseases (CVD) through inhibition of ER stress and oxidative stress. The present article reviews the involvement of ER stress and oxidative stress in cardiovascular dysfunction and the potential therapeutic implications.

scholarly journals Adiponectin Improves In Vitro Development of Cloned Porcine Embryos by Reducing Endoplasmic Reticulum Stress and Apoptosis

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 473
Author(s):  
Muhammad Rosyid Ridlo ◽  
Eui Hyun Kim ◽  
Anukul Taweechaipaisankul ◽  
Byeong Chun Lee ◽  
Geon A. Kim
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Early Stage ◽  
Formation Rate ◽  
Cell Number ◽  
Control Group ◽  
Cleavage Rate ◽  
Cell Stage ◽  
The Impact

The main factor of embryonic demise is endoplasmic reticulum (ER) stress. Successful attenuation of ER stress results in an improvement in embryo development. We studied the impact of adiponectin in the in vitro culture (IVC) of porcine embryos derived from parthenogenetic activation and somatic cell nuclear transfer (SCNT). The first experiment revealed that 15 and 30 μg/mL adiponectin treatments improved cleavage, blastocyst rates, and total cell number (TCN) of parthenogenetic embryos and reduced the expression of XBP1 compared to the 5 μg/mL adiponectin treatment and control groups (p < 0.05). The second experiment showed that cleavage rate, blastocyst formation rate, and TCN of blastocysts were improved in the 15 μg/mL adiponectin treatment group compared with the control group, with significantly reduced XBP1 expression in ≥4-cell stage SCNT embryos and blastocysts (p < 0.05). Treatment with 15 μg/mL adiponectin significantly improved the expression of XBP1 and reduced the expression of ER stress-related genes (uXBP1, sXBP1, PTPN1, and ATF4), increased the expression levels of pluripotency-related genes (Nanog and SOX2), and decreased apoptosis-related gene expression (Caspase-3). These results suggest that 15 μg/mL adiponectin enhanced the in vitro developmental capacity of early-stage SCNT porcine embryos by reducing ER stress and apoptosis.

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