Fattening chips: hypertrophy, feeding, and fasting of human white adipocytes in vitro

Abstract Liver X receptors (LXRs) are nuclear receptors with established roles in cholesterol, lipid, and carbohydrate metabolism, although their function in adipocytes is not well characterized. Increased adipose tissue mass in obesity is associated with increased adipocyte lipolysis. Fatty acids (FA) generated by lipolysis can be oxidized by mitochondrial β-oxidation, reesterified, or released from the adipocyte. The latter results in higher circulating levels of free FAs, in turn causing obesity-related metabolic complications. However, mitochondrial β-oxidation can at least in part counteract an increased output of FA into circulation. In this study, we provide evidence that activation of LXRs up-regulates mitochondrial β-oxidation in both human and murine white adipocytes. We also show that the expression of a kinase regulating the cellular fuel switch, pyruvate dehydrogenase kinase 4 (PDK4), is up-regulated by the LXR agonist GW3965 in both in vitro differentiated human primary adipocytes and differentiated murine 3T3-L1 cells. Moreover, activation of LXR causes PDK4-dependent phosphorylation of the pyruvate dehydrogenase complex, thereby decreasing its activity and attenuating glucose oxidation. The specificity of the GW3965 effect on oxidation was confirmed by RNA interference targeting LXRs. We propose that LXR has an important role in the regulation of substrate oxidation and the switch between lipids and carbohydrates as cellular fuel in both human and murine white adipocytes.

Download Full-text

Glutamine metabolism in white adipocytes incubated in vitro

Biochemical Society Transactions ◽

10.1042/bst0151071 ◽

1987 ◽

Vol 15 (6) ◽

pp. 1071-1071 ◽

Cited By ~ 4

Author(s):

RUI CURI ◽

JOHN M. KOWALCHUK ◽

ERIC A. NEWSHOLME

Keyword(s):

Glutamine Metabolism ◽

White Adipocytes

Download Full-text

Liraglutide suppresses obesity and promotes browning of white fat via miR-27b in vivo and in vitro

Journal of International Medical Research ◽

10.1177/03000605211055059 ◽

2021 ◽

Vol 49 (11) ◽

pp. 030006052110550

Author(s):

Xing Wang ◽

Shuchun Chen ◽

Dan Lv ◽

Zelin Li ◽

Luping Ren ◽

...

Keyword(s):

Uncoupling Protein ◽

Density Lipoprotein ◽

Peroxisome Proliferator ◽

Sprague Dawley ◽

Peroxisome Proliferator Activated Receptor ◽

Protein Levels ◽

White Adipocytes ◽

White Fat

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.

Download Full-text

Betatrophin knockdown induces beiging and mitochondria biogenesis of white adipocytes

Journal of Endocrinology ◽

10.1530/joe-19-0447 ◽

2020 ◽

Vol 245 (1) ◽

pp. 93-100 ◽

Cited By ~ 1

Author(s):

Zhe-Zhen Liao ◽

Xiao-Yan Qi ◽

Ya-Di Wang ◽

Jiao-Yang Li ◽

Qian-Qian Gu ◽

...

Keyword(s):

Signaling Pathway ◽

Ampk Signaling ◽

White Adipocytes ◽

Beige Adipocytes ◽

Beige Fat ◽

Mitochondria Biogenesis ◽

Paracrine Actions ◽

White Fat

Remodeling of energy-storing white fat into energy-consuming beige fat has led to a promising new approach to alleviate adiposity. Several studies have shown adipokines can induce white adipose tissue (WAT) beiging through autocrine or paracrine actions. Betatrophin, a novel adipokine, has been linked to energy expenditure and lipolysis but not clearly clarified. Here, we using high-fat diet-induced obesity to determine how betatrophin modulate beiging and adiposity. We found that betatrophin-knockdown mice displayed less white fat mass and decreased plasma TG and NEFA levels. Consistently, inhibition of betatrophin leads to the phenotype change of adipocytes characterized by increased mitochondria contents, beige adipocytes and mitochondria biogenesis-specific markers both in vivo and in vitro. Of note, blocking AMP-activated protein kinase (AMPK) signaling pathway is able to abolish enhanced beige-like characteristics in betatrophin-knockdown adipocytes. Collectively, downregulation of betatrophin induces beiging in white adipocytes through activation of AMPK signaling pathway. These processes suggest betatrophin as a latent therapeutic target for obesity.

Download Full-text

27 CLONING OF ADULT PIGS USING SCRIPTAID TREATMENT AND PREOVULATORY EMBRYO TRANSFER

Reproduction Fertility and Development ◽

10.1071/rdv23n1ab27 ◽

2011 ◽

Vol 23 (1) ◽

pp. 120

Author(s):

M. Albornoz ◽

C. Colato ◽

N. El-Beyrouthi ◽

F. Mellano ◽

A. Mellano ◽

...

Keyword(s):

Embryo Transfer ◽

Cell Lines ◽

Fibroblast Cell ◽

Cloning Efficiency ◽

Cell Stage ◽

Expected Time ◽

Reconstructed Embryos ◽

Adult Cell ◽

Skin Biopsies

There is growing interest in the use of swine in biomedical research. Cloning from cultured somatic cells (SCNT) has been the preferred method to generate genetically modified swine models. In a recent report, swine cloning efficiency was increased by treatment of reconstructed embryos with the inhibitor of deacetylase enzymes Scriptaid (Zhao et al. 2010 Cel. Reprog. 12, 75). Also, the timing of SCNT-embryo transfer with respect to the recipient’s expected time of ovulation was shown to affect cloning efficiency, whereas preovulatory embryo transfer resulted in a higher rate of cloned piglets born compared to postovulatory embryo transfer (Petersen et al. 2008 Cloning Stem Cells 10, 355). Therefore, our objective was to combine Scriptaid treatment and preovulatory embryo transfer in the same protocol for swine cloning. Cumulus–oocyte complexes aspirated from 3- to 6-mm diameter follicles were matured in vitro under standard conditions (Martinez Diaz et al. 2010 Cel. Reprog. 12, 85) and used as host oocytes for SCNT. Fibroblast cell lines were established from skin biopsies collected from 2 adult boars and cultured in DMEM supplemented with 10% FBS and 1% antibiotics. Oocytes were micromanipulated in Tyrode’s lactate-pyruvate-HEPES medium supplemented with 7.5 μg mL–1 cytochalasin B (CB) and electrically fused using a single DC pulse of 1.6 kV cm–1 for 70 μs. Activation was performed using ionomycin (15 μM/5 min) followed by exposure to CB (7.5 μg mL–1) and cyclohexemide (10 μg mL–1) for 5 h in porcine zygote medium (PZM-3; Yoshioka et al. 2002 Biol. Reprod. 66, 112). Reconstructed embryos were exposed to 500 nM Scriptaid for 10 to 12 h starting after ionomycin treatment. Oocytes were then washed and cultured in PZM-3 medium until transfer. Peripubertal recipient gilts were synchronized by oral administration of altrenogest (Regu-Mate®; 20 mg day–1) for 12 days, followed by 1.000 IU eCG injected on the last day of altrenogest treatment and 500 IU hCG 72 h later. 1-cell stage embryos were transferred into the oviduct after ∼20 h from hCG injection or 22 h before the expected ovulation time. Pregnancy was confirmed and monitored by ultrasonography and parturition was induced by injecting PGF2α at Day 115 of pregnancy. A total of 840 reconstructed embryos were transferred into 10 gilts [average 84 (range 60–110) embryos/gilt]. 4 gilts (40%) were detected to be pregnant 4 weeks after transfer, and 2 (20%) delivered 1 (1100 g) and 2 (950 and 850 g) healthy cloned piglets. The number of embryos transferred to these 2 gilts was 85 and 70. These results confirm that Scriptaid treatment and preovulatory embryo transfer can be applied in the same cloning protocol to produce cloned piglets from adult cell lines. To our knowledge, these are the first cloned pigs produced in Latin America.

Download Full-text

Effect of phytochemicals on phase II enzyme expression in infant human primary skin fibroblast cells

British Journal Of Nutrition ◽

10.1017/s0007114512000554 ◽

2012 ◽

Vol 108 (12) ◽

pp. 2158-2165 ◽

Cited By ~ 8

Author(s):

Eliz Warwick ◽

Aedín Cassidy ◽

Bryan Hanley ◽

Zeina E. Jouni ◽

Yongping Bao

Keyword(s):

Phase Ii ◽

Developmental Stages ◽

Later Life ◽

Phase Ii Enzymes ◽

Protein Levels ◽

Metabolic Plasticity ◽

Mrna Induction ◽

Age Related ◽

Adult Cell

Phase II metabolising enzymes enable the metabolism and excretion of potentially harmful substances in adults, but to date it is unclear whether dietary phytochemicals can induce phase II enzymes differently between adults and infants. We investigated the expression of phase II enzymes in an in vitro model of primary skin fibroblasts at three different developmental stages, 1 month, 2 years and adult, to examine potential differences in age-related phase II enzymes in response to different phytochemicals (5–20 μm) including sulphoraphane, quercetin and catechin. Following phytochemical treatment, a significant increase in mRNA of glutathione S-transferase A1 (GSTA1) and NAD(P)H:quinone oxidoreductase 1 (NQO1) was observed, with the most marked increases seen in response to sulphoraphane (3–10-fold for GSTA1, P = 0·001, and 6–35-fold for NQO1, P = 0·001–0·017). Catechin also induced 3–5-fold changes in NQO1 transcription, whereas quercetin had less effect on NQO1 mRNA induction in infant cells. Moreover, NQO1 protein levels were significantly increased in 2-year-old and adult cell models in response to sulphoraphane treatment. These results suggest that metabolic plasticity and response to xenobiotics may be different in infants and adults; and therefore the inclusion of phytochemicals in the infant diet may modulate their induction of phase II metabolism, thereby providing increased protection from potentially harmful xenobiotics in later life.

Download Full-text

Fruit of Gardenia jasminoides Induces Mitochondrial Activation and Non-Shivering Thermogenesis through Regulation of PPARγ

Antioxidants ◽

10.3390/antiox10091418 ◽

2021 ◽

Vol 10 (9) ◽

pp. 1418

Author(s):

Woo Yong Park ◽

Gahee Song ◽

Ja Yeon Park ◽

Kwan-Il Kim ◽

Kwang Seok Ahn ◽

...

Keyword(s):

Uncoupling Protein ◽

Exposure Model ◽

Peroxisome Proliferator ◽

Peroxisome Proliferator Activated Receptor ◽

Gardenia Jasminoides ◽

White Adipocytes ◽

Beige Adipocytes ◽

Underlying Mechanisms ◽

Induced Changes

The extract of the Gardenia jasminoides fruit (GJFE) can been consumed as an herbal tea or used as a yellow dye. Recently, studies report that GFJE exerts inhibitory effects on lipid accumulation and adipogenesis in white adipocytes. We evaluated the thermogenic actions of GJFE by focusing on mitochondrial activation and studying the underlying mechanisms. To investigate the role of GJFE on thermogenesis in mice, we used an acute cold exposure model. After 2 weeks of feeding, the cold tolerance of GJFE-fed mice was notably increased compared to PBS-fed mice. This was due to an increase in thermogenic proteins in the inguinal white adipose tissue of the cold-exposed mice. Moreover, GJFE significantly increased thermogenic factors such as peroxisome proliferator-activated receptor gamma (PPARγ), uncoupling protein 1 (UCP1), and PPARγ coactivator 1 alpha (PGC1α) in vitro as well. Factors related to mitochondrial abundance and functions were also induced by GJFE in white and beige adipocytes. However, the treatment of PPARγ inhibitor abolished the GJFE-induced changes, indicating that activation of PPARγ is critical for the thermogenic effect of GJFE. In conclusion, GJFE induces thermogenic action by activating mitochondrial function via PPARγ activation. Through these findings, we suggest GJFE as a potential anti-obesity agent with a novel mechanism involving thermogenic action in white adipocytes.

Download Full-text

Reversine: A Synthetic Purine with a Dual Activity as a Cell Dedifferentiating Agent and a Selective Anticancer Drug

Current Medicinal Chemistry ◽

10.2174/0929867326666190103120725 ◽

2020 ◽

Vol 27 (21) ◽

pp. 3448-3462

Author(s):

Marco Piccoli ◽

Andrea Ghiroldi ◽

Michelle M. Monasky ◽

Federica Cirillo ◽

Giuseppe Ciconte ◽

...

Keyword(s):

Stem Cells ◽

Current Knowledge ◽

Embryonic Stem ◽

Cell Types ◽

Cancer Drug ◽

Anti Cancer ◽

Adult Cell ◽

Induced Pluripotent

The development of new therapeutic applications for adult and embryonic stem cells has dominated regenerative medicine and tissue engineering for several decades. However, since 2006, induced Pluripotent Stem Cells (iPSCs) have taken center stage in the field, as they promised to overcome several limitations of the other stem cell types. Nonetheless, other promising approaches for adult cell reprogramming have been attempted over the years, even before the generation of iPSCs. In particular, two years before the discovery of iPSCs, the possibility of synthesizing libraries of large organic compounds, as well as the development of high-throughput screenings to quickly test their biological activity, enabled the identification of a 2,6-disubstituted purine, named reversine, which was shown to be able to reprogram adult cells to a progenitor-like state. Since its discovery, the effect of reversine has been confirmed on different cell types, and several studies on its mechanism of action have revealed its central role in inhibitory activity on several kinases implicated in cell cycle regulation and cytokinesis. These key features, together with its chemical nature, suggested a possible use of the molecule as an anti-cancer drug. Remarkably, reversine exhibited potent cytotoxic activity against several tumor cell lines in vitro and a significant effect in decreasing tumor progression and metastatization in vivo. Thus, 15 years since its discovery, this review aims at critically summarizing the current knowledge to clarify the dual role of reversine as a dedifferentiating agent and anti-cancer drug.

Download Full-text

Gomisin N from Schisandra chinensis Ameliorates Lipid Accumulation and Induces a Brown Fat-Like Phenotype through AMP-Activated Protein Kinase in 3T3-L1 Adipocytes

International Journal of Molecular Sciences ◽

10.3390/ijms21062153 ◽

2020 ◽

Vol 21 (6) ◽

pp. 2153

Author(s):

Kippeum Lee ◽

Yeon-Joo Lee ◽

Kui-Jin Kim ◽

Sungwoo Chei ◽

Heegu Jin ◽

...

Keyword(s):

Protein Kinase ◽

Lipid Accumulation ◽

Uncoupling Protein ◽

Brown Adipocyte ◽

Acid Oxidation ◽

Schisandra Chinensis ◽

White Adipocytes ◽

Gomisin N ◽

Amp Activated Protein Kinase

Obesity results from an imbalance between energy intake and energy expenditure, in which excess fat is stored as triglycerides (TGs) in white adipocytes. Recent studies have explored the anti-obesity effects of certain edible phytochemicals, which suppress TG accumulation and stimulate a brown adipocyte-like phenotype in white adipocytes. Gomisin N (GN) is an important bioactive component of Schisandra chinensis, a woody plant endemic to Asia. GN has antioxidant, anti-inflammatory and hepatoprotective effects in vivo and in vitro. However, the anti-obesity effects of GN in lipid metabolism and adipocyte browning have not yet been investigated. In the present study, we aimed to determine whether GN suppresses lipid accumulation and regulates energy metabolism, potentially via AMP-activated protein kinase (AMPK), in 3T3-L1 adipocytes. Our findings demonstrate that GN inhibited adipogenesis and lipogenesis in adipocyte differentiation. Also, GN not only increased the expression of thermogenic factors, including uncoupling protein 1 (UCP1), but also enhanced fatty acid oxidation (FAO) in 3T3-L1 cells. Therefore, GN may have a therapeutic benefit as a promising natural agent to combat obesity.

Download Full-text

Cold Exposure Differentially Stimulates Angiogenesis in BAT and WAT of Mice: Implication in Adrenergic Activation

Cellular Physiology and Biochemistry ◽

10.1159/000478680 ◽

2017 ◽

Vol 42 (3) ◽

pp. 974-986 ◽

Cited By ~ 7

Author(s):

Xiao Luo ◽

Ru Jia ◽

Xiao-qin Luo ◽

Guan Wang ◽

Qiang-ling Zhang ◽

...

Keyword(s):

Gene Expression ◽

Cold Exposure ◽

Angiogenic Factors ◽

Adipose Tissues ◽

Interscapular Brown Adipose Tissue ◽

White Adipocytes ◽

Adrenoceptor Agonist ◽

Brown Adipose

Background/Aims: To characterize the temporal profile of cold-induced angiogenesis in brown and white adipose tissues of mice in vivo and the temporal changes of angiogenic factors in primary mice brown (BA) and white adipocytes (WA) treated with β3-adrenoceptor agonist (CL316,243) in vitro. Methods: 8-week old male C57BL/6J mice were individually housed in conventional cages under cold exposure (4°C) for 1, 2, 3, 4 and 5 days. Interscapular brown adipose tissue (iBAT), inguinal subcutaneous (sWAT) and epididymal white adipose tissues (eWAT) were harvested for immunohistochemical and gene expression analysis. In vitro, primary mice BA and WA treated with or without CL316,243 were harvested for gene expression and protein secretion analysis. Results: A combination of morphological and genetic (Vegfa, Vegfr2, Hif-1α, Pai1 and Pedf) analyses demonstrated depot-specific angiogenesis in response to cold exposure. Upon CL316,243 treatment, angiogenic factors (Vegfa, Vegfr2, Hif-1α, Pai1 and Pedf) and secreted protein VEGFA were transiently increased in both BA and WA. Conclusion: Our results show that iBAT is highly responsive to cold-induced angiogenesis that is mainly supported by sWAT with a lesser extent by eWAT. Moreover, the angiogenesis is a transient process with the angiogenic factors may work in an autocrine/paracrine manner.

Download Full-text