The role of the G-protein coupled receptor 120 (GPR120) on the FGF21 system in white and brown adipose tissues

[eng] Obesity prevalence has tripled in the last fifty years. For this reason, it is considered the pandemic of the century. It is characterized by the accumulation of metabolic abnormalities triggered by an increase in the size of fat depots in the body. Hence, new therapies to pursue an amelioration of metabolic abnormalities and adipose tissue dysfunction caused by this energy imbalance are being explored. The tissue responsible for the storage of fat is adipose tissue and it was considered just as an energy reservoir until recently. Currently, it is known to be actively involved in energy homeostasis at the same time that it fulfills endocrine functions. Adipose tissue is divided into two main types, white adipose tissue (WAT) and brown adipose tissue (BAT). While energy storage is the main role of WAT, BAT is able to dissipate energy in the form of heat leading to an increased energy expenditure. Surprisingly, it has been reported that WAT has the ability to recruit cells of the brown phenotype and thus increase its energy expenditure in a process denominated as browning. BAT activity and WAT browning are important components of energy expenditure and therefore potential therapeutic targets for the treatment of obesity and its comorbidities. In this work, we show that GPR120 activation, a membrane receptor for polyunsaturated fatty acids (PUFAs), promotes BAT thermogenic activity and WAT browning. The tissue that reported the highest levels of GPR120 expression is BAT, followed by colon and WAT different deposits. In addition, it was discovered that thermal stress (cold exposure) causes an induction in the expression of GPR120 in adipose depots. Likewise, the activation of GPR120 induces an increase in oxygen consumption. Conversely, mice deficient of GPR120 show decreased temperature and UCP1 expression in neonatal BAT and decreased browning after cold exposure in adult WAT. The administration of natural or synthetic agonists of GPR120, such as omega-3 PUFAs or GW9508, induced brown and beige adipocyte differentiation as well as their thermogenic activation and glucose oxidation. This activation by n-3 PUFAs was dependent of GPR120 expression. In addition to these findings, it was revealed that the activation of GPR120 induces the expression and release of fibroblast growth factor-21 (FGF21) by BAT and WAT at the same time that it increases plasma FGF21 levels. FGF21 is a hormonal factor able to induce thermogenic activation of BAT and browning of WAT, both associated with an improvement in metabolic conditions. In the absence of GPR120, the levels of FGF21 under cold stress conditions are decreased. Furthermore, n-3 PUFAs and synthetic agonists do not induce the expression and release of FGF21 in animals and cells deficient of GPR120. Regarding the effects on the activation of BAT, browning of WAT and the increase in glucose oxidation by the activation of GPR120, these are all compromised in mice or adipocytes lacking FGF21. Therefore, it is concluded that GPR120 activation induces BAT thermogenic activity and WAT browning through a mechanism that involves the induction of FGF21.[spa] La obesidad es pandemia del siglo XXI y se caracteriza por desencadenar anomalías metabólicas debido al exceso de grasa almacenada en el organismo. Ello urge la exploración de nuevas terapias para su tratamiento. El tejido adiposo (TA) ha pasado de considerarse solo un depósito de energía a ser relacionado con el mantenimiento de la homeostasis energética. Se divide en dos tipos, tejido adiposo blanco (TAB) y tejido adiposo marrón (TAM). El primero sirve como almacén de energía y el segundo produce calor debido al desacoplamiento de la cadena respiratoria resultando en un gasto energético incrementado. El TAB tiene la capacidad de reclutar células del fenotipo marrón en un proceso denominado pardeamiento. La actividad del TAM y el pardeamiento del TAB son componentes importantes del gasto energético y blancos terapéuticos para el tratamiento de la obesidad. GPR120 es un receptor de membrana para ácidos grasos poliinsaturados (PUFAs) que demostró promover la activación del TAM y el pardeamiento del TAB. El TAM es el tejido que expresa GPR120 principalmente y el estrés térmico causa una inducción en la expresión de GPR120 en los depósitos adiposos. Conjuntamente, la activación de GPR120 induce la actividad termogénica del TAM y pardeamiento del TAB. Inversamente, los ratones deficientes de GPR120 muestran una activación de la termogénesis disminuida tras la exposición al frío. Además, la activación de GPR120 ha mostrado inducir la diferenciación de adipocitos marrón y beige así como su activación termogénica. Dicha activación conlleva a la inducción en la expresión y liberación del factor de crecimiento fibroblástico-21 (FGF21) por el TA así como un aumento en los niveles en sangre. FGF21 es un factor hormonal capaz de inducir la termogénesis en el TA y de mejorar las condiciones metabólicas. Los animales deficientes de GPR120 muestran niveles de FGF21 disminuidos tras la exposición a frío mientras que la falta de FGF21 comprometió la inducción de la termogénesis tras la activación de GPR120 en ratones y adipocitos. Se concluyó que la activación de GPR120 induce la actividad termogénica de la grasa marrón y el pardeamiento de la grasa blanca a través de la inducción de FGF21

Building of a flexible microfluidic plasmo-nanomechanical biosensor for live cell analysis

Biosensor devices can constitute an advanced tool for monitoring and study complex dynamic biological processes, as for example cellular adhesion. Cellular adhesion is a multipart process with crucial implications in physiology (i.e. immune response, tissue nature, architecture maintenance, or behaviour and expansion of tumor cells). This work focuses on offering a controlled methodology in order to fabricate a flexible plasmo-nanomechanical biosensor placed within a microfluidic channel as a new tool for future cell adhesion studies. We designed, fabricated, and optically and mechanically characterized this novel optical biosensor. As a proof-of-concept of its functionality, the biosensor was employed to observe fibroblasts adhesion in a cell culture. The device is configured by an hexagonal array of flexible rigid/soft polymeric nanopillars capped with plasmonic gold nanodisks integrated inside a microfluidic channel. The fabrication employs low-cost and large-scale replica molding techniques using two different polymers materials (EPOTECK OG142 and 310 M). By using those materials the spring constant of the polymer nanopillars (k) can be fabricated from 1.19E-02 [N/m] to 5.35E+00 [N/m] indicating different mechanical sensitivities to shear stress. Therefore, the biosensor has the feasibility to mimic soft and rigid tissues important for the description of cellular nanoscale behaviours. The biosensor exhibits a suitable bulk sensitivity of 164 nm or 206 nm/refractive index unit respectively, depending on the base material. The range of calculated forces goes from ≈1.98 nN to ≈.942 μN. This supports that the plasmo-nanomechanical biosensors could be employed as novel tool to study living cells behavior

Differential effects of dolutegravir, bictegravir and raltegravir in adipokines and inflammation markers on human adipocytes

Altres ajuts: European Regional Development Fund (FEDER); Gilead. European Union NextGeneration EU/PRTR.Aims: To assess the potential direct effects of the integrase strand-transfer inhibitors (INsTIs) dolutegravir, bictegravir, and raltegravir, drugs used as treatment for people living with human immunodeficiency virus (PLWH), on human adipose cells. Main methods: Drugs were added to the differentiation medium of human Simpson-Golabi-Behmel syndrome (SGBS) adipose cells and morphological adipogenesis was monitored for 10 days. Also, adipocytes were exposed to drugs following differentiation (day 14). The gene expression levels of selected adipogenesis markers, adipocyte metabolism markers, adipokines, and cytokines were determined by quantitative-reverse transcription polymerase-chain reaction. The release of adiponectin and leptin into the culture medium was measured using specific enzyme-linked immunosorbent assay, and release of interleukin-6 and chemokine (C[sbnd]C motif) ligand-2 using Multiplex assays. Key findings: Overall morphological adipogenesis was unaltered by INsTIs. The expression of adipogenesis marker genes (peroxisome proliferator-activated receptor-Ɣ and lipoprotein lipase) was slightly reduced in dolutegravir-treated differentiating adipocytes. Bictegravir repressed gene expression and the release of pro-inflammatory cytokines in differentiating adipocytes. Dolutegravir and raltegravir increased interleukin-6 gene expression, but only dolutegravir increased interleukin-6 release. Dolutegravir repressed adiponectin expression and release in differentiating adipocytes and had a similar but milder effect on leptin. Drug treatment of mature adipocytes reduced adiponectin gene expression in response to dolutegravir. Significance: The INsTIs studied do not have a significant effect on human adipose cell differentiation but exert distinct effects on gene expression and secretion of adipokines and cytokines. These findings will help understand and manage the effects of INsTI-containing treatments on body weight and metabolic dysregulation in PLWH

GPR120 controls neonatal brown adipose tissue thermogenic induction

Adaptive induction of thermogenesis in brown adipose tissue (BAT) is essential for the survival of mammals after birth. We herein show that G-coupled receptor protein-120 (GPR120) expression is dramatically induced after birth in mouse BAT. GPR120 expression in neonatal BAT is the highest among GPR120-expressing tissues in mouse at any developmental stage tested. The induction of GPR120 in neonatal BAT is caused by the postnatal thermal stress rather than by the initiation of suckling. GPR120-null neonates were found to be relatively intolerant to cold: close to one-third did not survive at 21ºC, but all such pups survived at 25ºC. Heat production in BAT was significantly impaired in GPR120-null pups. Deficiency in GPR120 did not modify brown adipocyte morphology or the anatomical architecture of BAT, as assessed by electron microscopy, but instead impaired the expression of UCP1 and the fatty acid oxidation capacity of neonatal BAT. Moreover, GPR120 deficiency impaired FGF21 gene expression in BAT and reduced plasma FGF21 levels. These results indicate that GPR120 is essential for neonatal adaptive thermogenesis through the control of the FGF21 system

Oral administration of a new HRI activator as a new strategy to improve high-fat-died-induced glucose intolerance, hepatic steatosis and hypertriglyceridemia through FGF21

BACKGROUND AND PURPOSE Fibroblast growth factor 21 (FGF21) has emerged as a therapeutic strategy for treating type 2 diabetes mellitus due to its antidiabetic effects, and this has led to the development of FGF21 longacting analogs. These compounds have some limitations, including requiring subcutaneous injection and their prolonged pharmacodynamic effect compared with native FGF21, which might be responsible for their reported side effects. EXPERIMENTAL APPROACH We have previously demonstrated that intraperitoneal administration of heme-regulated eukaryotic translation initiation factor 2α (eIF2α) kinase (HRI) activators increases hepatic and circulating levels of FGF21. In this study, we examined the effects of oral administration of a new HRI activator, EPB-53, on high-fat diet (HFD)-induced glucose intolerance, hepatic steatosis, and hypertriglyceridemia, compared with metformin. KEY RESULTS Administration of EPB-53 administration for the last two weeks, to mice fed a HFD for 10 weeks, reduced body weight gain, improved glucose intolerance, and prevented hepatic steatosis and hypertriglyceridemia; whereas metformin only ameliorated glucose intolerance. Moreover, EPB- 53, similarly to the reported effects of FGF21, reduced lipogenesis in cultured human hepatocytes and in the liver of mice fed a HFD. Administration of EPB-53 to Fgf21-knockout mice had no effects, demonstrating that its efficacy is dependent on this hormone. CONCLUSIONS AND IMPLICATIONS Overall, the findings of this study demonstrate that oral administration of HRI activators is a promising strategy for the treatment of type 2 diabetes mellitus and non-alcoholic fatty liver disease by increasing FGF21

Differential effects of dolutegravir, bictegravir and raltegravir in adipokines and inflammation markers on human adipocytes.

Aims: To assess the potential direct effects of the integrase strand-transfer inhibitors (INsTIs) dolutegravir, bictegravir, and raltegravir, drugs used as treatment for people living with human immunodeficiency virus (PLWH), on human adipose cells. Main methods: Drugs were added to the differentiation medium of human Simpson-Golabi-Behmel syndrome (SGBS) adipose cells and morphological adipogenesis was monitored for 10 days. Also, adipocytes were exposed to drugs following differentiation (day 14). The gene expression levels of selected adipogenesis markers, adipocyte metabolism markers, adipokines, and cytokines were determined by quantitative-reverse transcription polymerase-chain reaction. The release of adiponectin and leptin into the culture medium was measured using specific enzyme-linked immunosorbent assay, and release of interleukin-6 and chemokine (CC motif) ligand-2 using Multiplex assays. Key findings: Overall morphological adipogenesis was unaltered by INsTIs. The expression of adipogenesis marker genes (peroxisome proliferator-activated receptor-Ɣ and lipoprotein lipase) was slightly reduced in dolutegravir-treated differentiating adipocytes. Bictegravir repressed gene expression and the release of pro-inflammatory cytokines in differentiating adipocytes. Dolutegravir and raltegravir increased interleukin-6 gene expression, but only dolutegravir increased interleukin-6 release. Dolutegravir repressed adiponectin expression and release in differentiating adipocytes and had a similar but milder effect on leptin. Drug treatment of mature adipocytes reduced adiponectin gene expression in response to dolutegravir. Significance: The INsTIs studied do not have a significant effect on human adipose cell differentiation but exert distinct effects on gene expression and secretion of adipokines and cytokines. These findings will help understand and manage the effects of INsTI-containing treatments on body weight and metabolic dysregulation in PLWH

Maresin 1 activates brown adipose tissue and promotes browning of white adipose tissue in mice

Objective Maresin 1 (MaR1) is a docosahexaenoic acid-derived proresolving lipid mediator with insulin-sensitizing and anti-steatosis properties. Here, we aim to unravel MaR1 actions on brown adipose tissue (BAT) activation and white adipose tissue (WAT) browning. Methods MaR1 actions were tested in cultured murine brown adipocytes and in human mesenchymal stem cells (hMSC)-derived adipocytes. In vivo effects of MaR1 were tested in diet-induced obese (DIO) mice and lean WT and Il6 knockout (Il6−/−) mice. Results In cultured differentiated murine brown adipocytes, MaR1 reduces the expression of inflammatory genes, while stimulates glucose uptake, fatty acid utilization and oxygen consumption rate, along with the upregulation of mitochondrial mass and genes involved in mitochondrial biogenesis and function and the thermogenic program. In Leucine Rich Repeat Containing G Protein-Coupled Receptor 6 (LGR6)-depleted brown adipocytes using siRNA, the stimulatory effect of MaR1 on thermogenic genes was abrogated. In DIO mice, MaR1 promotes BAT remodeling, characterized by higher expression of genes encoding for master regulators of mitochondrial biogenesis and function and iBAT thermogenic activation, together with increased M2 macrophage markers. In addition, MaR1-treated DIO mice exhibit a better response to cold-induced BAT activation. Moreover, MaR1 induces a beige adipocyte signature in inguinal WAT of DIO mice and in hMSC-derived adipocytes. MaR1 potentiates Il6 expression in brown adipocytes and BAT of cold exposed lean WT mice. Interestingly, the thermogenic properties of MaR1 were abrogated in Il6−/− mice. Conclusions These data reveal MaR1 as a novel agent that promotes BAT activation and WAT browning by regulating thermogenic program in adipocytes and M2 polarization of macrophages. Moreover, our data suggest that LGR6 receptor is mediating MaR1 actions on brown adipocytes, and that IL-6 is required for the thermogenic effects of MaR1

Hepatitis C virus seroprevalence in the general female population from 8 countries

Background: Hepatitis C virus (HCV) infection is a significant global health issue because it is widespread and persistent and can cause serious liver diseases. Objectives: The aim of this study is to estimate HCV prevalence in women from the general population in different geographical areas worldwide and to assess the potential role of sexual behaviour in the virus transmission. Study design: Each participating centre recruited a random sample of women from the general population aged from less than 20 to more than 75 years. The study included 8130 women from 8 countries with information on sociodemographic factors, reproductive and sexual behaviour, smoking habit and HPV DNA through individual interviews. A blood sample was also collected to perform serological tests. We estimated the prevalence ratios associated to HCV to evaluate the effect of sexual behaviour in viral transmission. Results: Women were reactive to a minimum of two HCV antigens, including at least one non structural protein were considered as positive (33% of the samples were classified as positive, 40% as negative, and 27% as indeterminate (N = 402), that were considered as not positive). The age-adjusted HCV seroprevalence varied significantly by regions (0.3% in Argentina to 21.1% in Nigeria). We found no association between HCV prevalence and age, educational level, smoking habit and any of the available variables for sexual behaviour and reproductive history. Conclusions: This large study showed heterogeneous distribution of HCV seroprevalence in female and provides evidence of the null impact of sexual behaviour in HCV transmission. (C) 2015 Elsevier B.V. All rights reserved

Maresin 1 activates brown adipose tissue and promotes browning of white adipose tissue in mice

[Objective]: Maresin 1 (MaR1) is a docosahexaenoic acid-derived proresolving lipid mediator with insulin-sensitizing and anti-steatosis properties. Here, we aim to unravel MaR1 actions on brown adipose tissue (BAT) activation and white adipose tissue (WAT) browning. [Methods]: MaR1 actions were tested in cultured murine brown adipocytes and in human mesenchymal stem cells (hMSC)-derived adipocytes. In vivo effects of MaR1 were tested in diet-induced obese (DIO) mice and lean WT and Il6 knockout (Il6−/−) mice. [Results]: In cultured differentiated murine brown adipocytes, MaR1 reduces the expression of inflammatory genes, while stimulates glucose uptake, fatty acid utilization and oxygen consumption rate, along with the upregulation of mitochondrial mass and genes involved in mitochondrial biogenesis and function and the thermogenic program. In Leucine Rich Repeat Containing G Protein-Coupled Receptor 6 (LGR6)-depleted brown adipocytes using siRNA, the stimulatory effect of MaR1 on thermogenic genes was abrogated. In DIO mice, MaR1 promotes BAT remodeling, characterized by higher expression of genes encoding for master regulators of mitochondrial biogenesis and function and iBAT thermogenic activation, together with increased M2 macrophage markers. In addition, MaR1-treated DIO mice exhibit a better response to cold-induced BAT activation. Moreover, MaR1 induces a beige adipocyte signature in inguinal WAT of DIO mice and in hMSC-derived adipocytes. MaR1 potentiates Il6 expression in brown adipocytes and BAT of cold exposed lean WT mice. Interestingly, the thermogenic properties of MaR1 were abrogated in Il6−/− mice. [Conclusions]: These data reveal MaR1 as a novel agent that promotes BAT activation and WAT browning by regulating thermogenic program in adipocytes and M2 polarization of macrophages. Moreover, our data suggest that LGR6 receptor is mediating MaR1 actions on brown adipocytes, and that IL-6 is required for the thermogenic effects of MaR1.The authors received support for the current study from Ministerio de Ciencia e Innovación/Agencia Estatal de Investigación, Spain, MCIN/AEI/10.13039/501100011033 (grants BFU2012-36089 to MJM-A; BFU2015-65937-R to MJM-A, SL-C; PID2019-106982RB-I00 to MJM-A; SAF2017-83813-C3-1-R to LH and PID2021-122766OB-I00 to AMV), cofinanced by the European Regional Development Fund (ERDF); Dept. of Health, Navarra Government (67–2015) to MJM-A; Merck Health Foundation to LH; CIBEROBN (CB12/03/30002; CB06/03/0001; CB06/03/0025) and CIBERDEM (CB07/08/0033) from ISCIII (Spain). “Juan de la Cierva” Grant to MF-G (IJCI-2016-30025) funded by MCIN/AEI/10.13039/501100011033. Predoctoral grant to LML (Asociación de Amigos, Universidad de Navarra/“la Caixa” Banking Foundation) and to LM-F (FPI, BES-2013-064970). S.Q.-V. is supported by a fellowship from the Vicente Lopez Program (Eurecat).Peer reviewe

Reciprocal Effects of Antiretroviral Drugs Used To Treat HIV Infection on the Fibroblast Growth Factor 21/β-Klotho System

Following antiretroviral therapy, HIV-infected patients show increased circulating levels of the antidiabetic hormone fibroblast growth factor 21 (FGF21). In contrast, the expression of the FGF21-obligatory coreceptor β-Klotho (KLB) is reduced in target tissues. This situation is comparable to the FGF21 resistance status observed in obesity and type 2 diabetes. Here, we performed the first systematic study of the effects of distinct members of different antiretroviral drug classes on the FGF21/KLB system in human hepatic, adipose, and skeletal muscle cells. Most protease inhibitors and the nonnucleoside reverse transcriptase inhibitor efavirenz induced FGF21 gene expression. Neither nucleoside reverse transcriptase inhibitors nor the viral entry inhibitor maraviroc had any effect. Among the integrase inhibitors, elvitegravir significantly induced FGF21 expression, whereas raltegravir had minor effects only in adipose cells. In human hepatocytes and adipocytes, known target cells of FGF21 action, efavirenz, elvitegravir, and the lopinavir-ritonavir combination exerted inhibitory effects on KLB gene expression. Drug treatments that elicited FGF21 induction/KLB repression were those found to induce endoplasmic reticulum (ER) stress and oxidative stress. Notably, the pharmacological agents thapsigargin and tunicamycin, which induce these stress pathways, mimicked the effects of drug treatments. Moreover, pharmacological inhibitors of either ER or oxidative stress significantly impaired lopinavir-ritonavir-induced regulation of FGF21, but not KLB. In conclusion, the present in vitro screen study identifies the antiretroviral drugs that affect FGF21/KLB expression in human cells. The present results could have important implications for the management of comorbidities resulting from side effects of specific antiretroviral drugs for the treatment of HIV-infected patients