scholarly journals The Suv420h histone methyltransferases regulate PPAR-γ and energy expenditure in response to environmental stimuli

2019 ◽  
Vol 5 (4) ◽  
pp. eaav1472 ◽  
Author(s):  
Simona Pedrotti ◽  
Roberta Caccia ◽  
Maria Victoria Neguembor ◽  
Jose Manuel Garcia-Manteiga ◽  
Giulia Ferri ◽  
...  

Obesity and its associated metabolic abnormalities have become a global emergency with considerable morbidity and mortality. Epidemiologic and animal model data suggest an epigenetic contribution to obesity. Nevertheless, the cellular and molecular mechanisms through which epigenetics contributes to the development of obesity remain to be elucidated. Suv420h1 and Suv420h2 are histone methyltransferases responsible for chromatin compaction and gene repression. Through in vivo, ex vivo, and in vitro studies, we found that Suv420h1 and Suv420h2 respond to environmental stimuli and regulate metabolism by down-regulating peroxisome proliferator–activated receptor gamma (PPAR-γ), a master transcriptional regulator of lipid storage and glucose metabolism. Accordingly, mice lacking Suv420h proteins activate PPAR-γ target genes in brown adipose tissue to increase mitochondria respiration, improve glucose tolerance, and reduce adipose tissue to fight obesity. We conclude that Suv420h proteins are key epigenetic regulators of PPAR-γ and the pathways controlling metabolism and weight balance in response to environmental stimuli.

2019 ◽  
Vol 20 (7) ◽  
pp. 1618 ◽  
Author(s):  
Abeer Fayyad ◽  
Amir Khan ◽  
Sallam Abdallah ◽  
Sara Alomran ◽  
Khalid Bajou ◽  
...  

Obesity is a major risk for diabetes. Brown adipose tissue (BAT) mediates production of heat while white adipose tissue (WAT) function in the storage of fat. Roles of BAT in the treatment of obesity and related disorders warrants more investigation. Peroxisome proliferator activator receptor gamma (PPAR-γ) is the master regulator of both BAT and WAT adipogenesis and has roles in glucose and fatty acid metabolism. Adipose tissue is the major expression site for PPAR-γ. In this study, the effects of rosiglitazone on the brown adipogenesis and the association of MAPK and PI3K pathways was investigated during the in vitro adipogenic differentiation of telomerase transformed mesenchymal stromal cells (iMSCs). Our data indicate that 2 µM rosiglitazone enhanced adipogenesis by over-expression of PPAR-γ and C/EBP-α. More specifically, brown adipogenesis was enhanced by the upregulation of EBF2 and UCP-1 and evidenced by multilocular fatty droplets morphology of the differentiated adipocytes. We also found that rosiglitazone significantly activated MAPK and PI3K pathways at the maturation stage of differentiation. Overall, the results indicate that rosiglitazone induced overexpression of PPAR-γ that in turn enhanced adipogenesis, particularly browning adipogenesis. This study reports the browning effects of rosiglitazone during the differentiation of iMSCs into adipocytes in association with the activation of MAPK and PI3K signaling pathways.


Marine Drugs ◽  
2018 ◽  
Vol 16 (11) ◽  
pp. 431 ◽  
Author(s):  
Rosa Vitale ◽  
Enrico D'Aniello ◽  
Stefania Gorbi ◽  
Andrea Martella ◽  
Cristoforo Silvestri ◽  
...  

Although the chemical warfare between invasive and native species has become a central problem in invasion biology, the molecular mechanisms by which bioactive metabolites from invasive pests influence local communities remain poorly characterized. This study demonstrates that the alkaloid caulerpin (CAU)—a bioactive component of the green alga Caulerpa cylindracea that has invaded the entire Mediterranean basin—is an agonist of peroxisome proliferator-activated receptors (PPARs). Our interdisciplinary study started with the in silico prediction of the ligand-protein interaction, which was then validated by in vivo, ex vivo and in vitro assays. On the basis of these results, we candidate CAU as a causal factor of the metabolic and behavioural disorders observed in Diplodus sargus, a native edible fish of high ecological and commercial relevance, feeding on C. cylindracea. Moreover, given the considerable interest in PPAR activators for the treatment of relevant human diseases, our findings are also discussed in terms of a possible nutraceutical/pharmacological valorisation of the invasive algal biomasses, supporting an innovative strategy for conserving biodiversity as an alternative to unrealistic campaigns for the eradication of invasive pests.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Francesca-Maria Raffaelli ◽  
Julia Resch ◽  
Rebecca Oelkrug ◽  
K. Alexander Iwen ◽  
Jens Mittag

AbstractBrown adipose tissue (BAT) thermogenesis is considered a potential target for treatment of obesity and diabetes. In vitro data suggest dopamine receptor signaling as a promising approach; however, the biological relevance of dopamine receptors in the direct activation of BAT thermogenesis in vivo remains unclear. We investigated BAT thermogenesis in vivo in mice using peripheral administration of D1-agonist SKF38393 or D2-agonist Sumanirole, infrared thermography, and in-depth molecular analyses of potential target tissues; and ex vivo in BAT explants to identify direct effects on key thermogenic markers. Acute in vivo treatment with the D1- or D2-agonist caused a short spike or brief decrease in BAT temperature, respectively. However, repeated daily administration did not induce lasting effects on BAT thermogenesis. Likewise, neither agonist directly affected Ucp1 or Dio2 mRNA expression in BAT explants. Taken together, the investigated agonists do not seem to exert lasting and physiologically relevant effects on BAT thermogenesis after peripheral administration, demonstrating that D1- and D2-receptors in iBAT are unlikely to constitute targets for obesity treatment via BAT activation.


2000 ◽  
pp. 71-78 ◽  
Author(s):  
A Gorla-Bajszczak ◽  
C Siegrist-Kaiser ◽  
O Boss ◽  
AG Burger ◽  
CA Meier

OBJECTIVE: Examination of the pattern of expression of peroxisome proliferator-activated receptor (PPAR) isoforms alpha and gamma in a model of obesity. DESIGN: Examination of adipose tissue and primary adipocyte cultures from lean and obese Zucker rats at different ages (28 days and 12 weeks). METHODS: mRNA levels were measured by RNase protection assay.RESULTS: The highest levels of PPARalpha and gamma mRNA were present in brown adipose tissue (BAT), followed by liver and white adipose tissue (WAT) for the alpha and gamma subtypes, respectively, at both ages examined. PPARalpha was expressed 100-fold higher in BAT compared with WAT, and PPARgamma mRNA levels were 2-fold higher in the WAT of obese compared with lean rats. PPARalpha and gamma expression was minimal in m. soleus, although higher levels of PPARgamma were found in the diaphragm. In marked contrast to the findings in vivo, virtually no PPARalpha mRNA could be detected in BAT cultures differentiated in vitro. CONCLUSION: PPARalpha and gamma are most highly expressed in BAT in vivo. However, PPARalpha is undetectable in brown adipose cells in vitro, suggesting that the expression of this receptor is induced by some external stimuli. In addition, the expression of PPARgamma was increased in WAT from young obese animals, compatible with an early adaptive phenomenon. Finally, the presence of PPARgamma mRNA is detectable only in particular muscles, such as the diaphragm, suggesting the possibility of an influence of fiber type on its expression, although exercise did not influence the expression of PPARgamma in other skeletal muscles.


2020 ◽  
Vol 6 (49) ◽  
pp. eabc6250
Author(s):  
Andréa Livia Rocha ◽  
Tanes Imamura de Lima ◽  
Gerson Profeta de Souza ◽  
Renan Oliveira Corrêa ◽  
Danilo Lopes Ferrucci ◽  
...  

MicroRNAs (miRNAs) have been implicated in oxidative metabolism and brown/beige adipocyte identity. Here, we tested whether widespread changes in miRNA expression promoted by treatment with the small-molecule enoxacin cause browning and prevent obesity. Enoxacin mitigated diet-induced obesity in mice, and this was associated with increased energy expenditure. Consistently, subcutaneous white and brown adipose tissues and skeletal muscle of enoxacin-treated mice had higher levels of markers associated with thermogenesis and oxidative metabolism. These effects were cell autonomous since they were recapitulated in vitro in murine and human cell models. In preadipocytes, enoxacin led to a reduction of miR-34a-5p expression and up-regulation of its target genes (e.g., Fgfr1, Klb, and Sirt1), thus increasing FGF21 signaling and promoting beige adipogenesis. Our data demonstrate that enoxacin counteracts obesity by promoting thermogenic signaling and inducing oxidative metabolism in adipose tissue and skeletal muscle in a mechanism that involves, at least in part, miRNA-mediated regulation.


2005 ◽  
Vol 288 (3) ◽  
pp. H1037-H1043 ◽  
Author(s):  
Ernesto L. Schiffrin

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that heterodimerize with the retinoid X receptor and then modulate the function of many target genes. Three PPARs are known: α, β/δ, and γ. The better known are PPAR-α and PPAR-γ, which may be activated by different synthetic agonists, although the endogenous ligands are unknown. PPAR-α is involved in fatty acid oxidation and expressed in the liver, kidney, and skeletal muscle, whereas PPAR-γ is involved in fat cell differentiation, lipid storage, and insulin sensitivity. However, both have been shown to be present in variable amounts in cardiovascular tissues, including endothelium, smooth muscle cells, macrophages, and the heart. The activators of PPAR-α (fibrates) and PPAR-γ (thiazolidinediones or glitazones) antagonized the actions of angiotensin II in vivo and in vitro and exerted cardiovascular antioxidant and anti-inflammatory effects. PPAR activators lowered blood pressure, induced favorable effects on the heart, and corrected vascular structure and endothelial dysfunction in several rodent models of hypertension. Activators of PPARs may become therapeutic agents useful in the prevention of cardiovascular disease beyond their effects on carbohydrate and lipid metabolism. Some side effects, such as weight gain, as well as documented aggravation of advanced heart failure through fluid retention by glitazones, may, however, limit their therapeutic application in prevention of cardiovascular disease.


2009 ◽  
Vol 23 (7) ◽  
pp. 975-988 ◽  
Author(s):  
Francine M. Gregoire ◽  
Fang Zhang ◽  
Holly J. Clarke ◽  
Thomas A. Gustafson ◽  
Dorothy D. Sears ◽  
...  

Abstract MBX-102/JNJ39659100 (MBX-102) is in clinical development as an oral glucose-lowering agent for the treatment of type 2 diabetes. MBX-102 is a nonthiazolidinedione (TZD) selective partial agonist of peroxisome proliferator-activated receptor (PPAR)-γ that is differentiated from the TZDs structurally, mechanistically, preclinically and clinically. In diabetic rodent models, MBX-102 has insulin-sensitizing and glucose-lowering properties comparable to TZDs without dose-dependent increases in body weight. In vitro, in contrast with full PPAR-γ agonist treatment, MBX-102 fails to drive human and murine adipocyte differentiation and selectively modulates the expression of a subset of PPAR-γ target genes in mature adipocytes. Moreover, MBX-102 does not inhibit osteoblastogenesis of murine mesenchymal cells. Compared with full PPAR-γ agonists, MBX-102 displays differential interactions with the PPAR-γ ligand binding domain and possesses reduced ability to recruit coactivators. Interestingly, in primary mouse macrophages, MBX-102 displays enhanced antiinflammatory properties compared with other PPAR-γ or α/γ agonists, suggesting that MBX-102 has more potent transrepression activity. In summary, MBX-102 is a selective PPAR-γ modulator with weak transactivation but robust transrepression activity. MBX-102 exhibits full therapeutic activity without the classical PPAR-γ side effects and may represent the next generation insulin sensitizer.


2016 ◽  
Vol 16 (4) ◽  
pp. 497-511 ◽  
Author(s):  
Hong Wang ◽  
Xi Yan ◽  
Li-Ya Ji ◽  
Xi-Tuan Ji ◽  
Ping Wang ◽  
...  

Gliomas are the most common primary malignant brain tumor with poor prognosis, characterized by a highly heterogeneous cell population, extensive proliferation, and migration. A lot of molecular mechanisms regulate gliomas development and invasion, including abnormal expression of oncogenes and variation of epigenetic modification. MicroRNAs could affect cell growth and functions. Several reports have demonstrated that miR-139 plays multifunctions in kinds of solid tumors through different pathways. However, the antitumor mechanisms of this miR-139 are not unveiled in detail. In this study, we not only validated the low expression level of miR-139 in glioma tissues and cell lines but also detected the effect of miR-139 on modulating gliomas proliferation and invasion both in vitro and in vivo. We identified insulin-like growth factor 1 receptor, associate of Myc 1, and peroxisome proliferator-activated receptor γ coactivator 1β as direct targets of miR-139 and the levels of them were all inversely correlated with miR-139 in gliomas. Insulin like growth factor 1 receptor promoted gliomas invasion through Akt signaling and increased proliferation in the peroxisome proliferator-activated receptor γ coactivator 1β-dependent way. Associate of Myc 1 also facilitated gliomas progression by activating c-Myc pathway. Overexpression of the target genes could retrieve the antitumor function of miR-139, respectively, in different degrees. The nude mice transplantation tumor experiment displayed that glioma cells stably expressed miR-139 growth much slower in vivo than the negative control cells. Taken together, these findings suggested miR-139 acted as a favorable factor against gliomas progression and uncovered a novel regulatory mechanism, which may provide a new evidenced prognostic marker and therapeutic target for gliomas.


2003 ◽  
Vol 373 (1) ◽  
pp. 155-165 ◽  
Author(s):  
Aline MEIRHAEGHE ◽  
Vivion CROWLEY ◽  
Carol LENAGHAN ◽  
Christopher LELLIOTT ◽  
Kath GREEN ◽  
...  

PGC1α is a co-activator involved in adaptive thermogenesis, fatty-acid oxidation and gluconeogenesis. We describe the identification of several isoforms of a new human PGC1α homologue, cloned independently and named PGC1β. The human PGC1β gene is localized to chromosome 5, has 13 exons and spans more than 78 kb. Two different 5′ and 3′ ends due to differential splicing were identified by rapid amplification of cDNA ends PCR and screening of human cDNA libraries. We show that PGC1β variants in humans, mice and rats are expressed predominantly in heart, brown adipose tissue, brain and skeletal muscle. PGC1β expression, unlike PGC1α, is not up-regulated in brown adipose tissue in response to cold or obesity. Fasting experiments showed that PGC1α, but not PGC1β, is induced in liver and this suggests that only PGC1α is involved in the hepatic gluconeogenesis. No changes in PGC1β gene expression were observed associated with exercise. Human PGC1β-1a and −2a isoforms localized to the cell nucleus and, specifically, the isoform PGC1β-1a co-activated peroxisome-proliferator-activated receptor-γ, -α and the thyroid hormone receptor β1. Finally, we show that ectopic expression PGC1β leads to increased mitochondrial number and basal oxygen consumption. These results suggest that PGC1β may play a role in constitutive adrenergic-independent mitochondrial biogenesis.


2020 ◽  
Author(s):  
Anthony R. Angueira ◽  
Alexander P. Sakers ◽  
Lan Cheng ◽  
Rojesh Shrestha ◽  
Chihiro Okada ◽  
...  

SummaryBrown adipose tissue can expend large amounts of energy and thus increasing its amount or activity is a promising therapeutic approach to combat metabolic disease. In humans, major deposits of brown fat cells are found intimately associated with large blood vessels, corresponding to perivascular adipose tissue (PVAT). However, the cellular origins of PVAT are poorly understood. Here, we applied single cell transcriptomic analyses, ex vivo adipogenesis assays, and genetic fate mapping in vivo to determine the identity of perivascular adipocyte progenitors. We found that thoracic PVAT initially develops from a fibroblastic lineage, comprising progenitor cells (Pdgfra+;Ly6a+;Pparg−) and preadipocytes (Pdgfra+;Ly6a−;Pparg+). Progenitors and preadipocytes in PVAT shared transcriptional similarity with analogous cell types in white adipose tissue, pointing towards a conserved adipose cell lineage hierarchy. Interestingly, the aortic adventitia of adult animals contained a novel population of adipogenic smooth muscle cells (Myh11+; Pdgfra−; Pparg+) possessing the capacity to generate adipocytes in vitro and in vivo. Taken together, these studies define distinct populations of fibroblastic and smooth muscle progenitor cells for thermogenic PVAT, providing a crucial foundation for developing strategies to augment brown fat activity.


Sign in / Sign up

Export Citation Format

Share Document