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Chirivi M, Contreras GA. Endotoxin-induced alterations of adipose tissue function: a pathway to bovine metabolic stress. J Anim Sci Biotechnol 2024; 15:53. [PMID: 38581064 PMCID: PMC10998405 DOI: 10.1186/s40104-024-01013-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 02/14/2024] [Indexed: 04/07/2024] Open
Abstract
During the periparturient period, dairy cows exhibit negative energy balance due to limited appetite and increased energy requirements for lactogenesis. The delicate equilibrium between energy availability and expenditure puts cows in a state of metabolic stress characterized by excessive lipolysis in white adipose tissues (AT), increased production of reactive oxygen species, and immune cell dysfunction. Metabolic stress, especially in AT, increases the risk for metabolic and inflammatory diseases. Around parturition, cows are also susceptible to endotoxemia. Bacterial-derived toxins cause endotoxemia by promoting inflammatory processes and immune cell infiltration in different organs and systems while impacting metabolic function by altering lipolysis, mitochondrial activity, and insulin sensitivity. In dairy cows, endotoxins enter the bloodstream after overcoming the defense mechanisms of the epithelial barriers, particularly during common periparturient conditions such as mastitis, metritis, and pneumonia, or after abrupt changes in the gut microbiome. In the bovine AT, endotoxins induce a pro-inflammatory response and stimulate lipolysis in AT, leading to the release of free fatty acids into the bloodstream. When excessive and protracted, endotoxin-induced lipolysis can impair adipocyte's insulin signaling pathways and lipid synthesis. Endotoxin exposure can also induce oxidative stress in AT through the production of reactive oxygen species by inflammatory cells and other cellular components. This review provides insights into endotoxins' impact on AT function, highlighting the gaps in our knowledge of the mechanisms underlying AT dysfunction, its connection with periparturient cows' disease risk, and the need to develop effective interventions to prevent and treat endotoxemia-related inflammatory conditions in dairy cattle.
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Affiliation(s)
- Miguel Chirivi
- Department of Large Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA
| | - G Andres Contreras
- Department of Large Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA.
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2
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Zhang W, Liu S, Kong L, Wu S, Zhong Z, Yu L, Yang Q, Zhang J, Li J, Zheng G. Lipopolysaccharide-induced persistent inflammation ameliorates fat accumulation by promoting adipose browning in vitro and in vivo. Int J Biol Macromol 2023; 252:126511. [PMID: 37625745 DOI: 10.1016/j.ijbiomac.2023.126511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 07/16/2023] [Accepted: 08/23/2023] [Indexed: 08/27/2023]
Abstract
This work aimed to explore whether the persistent inflammation induced by lipopolysaccharide (LPS) ameliorates fat accumulation by promoting adipose browning in vitro and in vivo. LPS over 1 ng/mL reduced lipid accumulation while increasing the expressions of specific genes involved in inflammation, mitochondrial biogenesis, and adipose browning in 3T3-L1 adipocytes. Moreover, LPS in intraperitoneal injection decreased white adipose tissue weight and elevated interscapular brown adipose tissue weight in mice. According to RT-PCR and western blot analysis results, the expressions of genes and proteins related to inflammation, mitochondrial biogenesis, lipolysis, and brown or beige markers in different tissues were elevated after LPS intervention. Cumulatively, LPS-induced persistent inflammation may potentially ameliorate fat accumulation by facilitating adipose browning in 3T3-L1 adipocytes and mice. These results offer new perspectives into the effect of persistent inflammation induced by LPS on regulating fat metabolism, thereby reducing fat accumulation by boosting adipose browning procedure.
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Affiliation(s)
- Wenkai Zhang
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Shanshan Liu
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Li Kong
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Shaofu Wu
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Zhen Zhong
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Longhui Yu
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Qinru Yang
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Jinfeng Zhang
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Jingen Li
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China.
| | - Guodong Zheng
- Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University, Nanchang 330045, China.
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Oliveras-Cañellas N, Latorre J, Santos-González E, Lluch A, Ortega F, Mayneris-Perxachs J, Fernández-Real JM, Moreno-Navarrete JM. Inflammatory response to bacterial lipopolysaccharide drives iron accumulation in human adipocytes. Biomed Pharmacother 2023; 166:115428. [PMID: 37677967 DOI: 10.1016/j.biopha.2023.115428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/23/2023] [Accepted: 08/30/2023] [Indexed: 09/09/2023] Open
Abstract
The association among increased inflammation, disrupted iron homeostasis, and adipose tissue dysfunction in obesity has been widely recognized. However, the specific impact of inflammation on iron homeostasis during human adipogenesis and in adipocytes remains poorly understood. In this study, we investigated the effects of bacterial lipopolysaccharide (LPS) on iron homeostasis during human adipocyte differentiation, in fully differentiated adipocytes, and in human adipose tissue. We found that LPS-induced inflammation hindered adipogenesis and led to a gene expression profile indicative of intracellular iron accumulation. This was accompanied by increased expression of iron importers (TFRC and SLC11A2), markers of intracellular iron accumulation (FTH, CYBA, FTL, and LCN2), and decreased expression of iron exporter-related genes (SLC40A1), concomitant with elevated intracellular iron levels. Mechanistically, RNA-seq analysis and gene knockdown experiments revealed the significant involvement of iron importers SLC39A14, SLC39A8, and STEAP4 in LPS-induced intracellular iron accumulation in human adipocytes. Notably, markers of LPS signaling pathway-related inflammation were also associated with a gene expression pattern indicative of intracellular iron accumulation in human adipose tissue, corroborating the link between LPS-induced inflammation and iron accumulation at the tissue level. In conclusion, our findings demonstrate that induction of adipocyte inflammation disrupts iron homeostasis, resulting in adipocyte iron overload.
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Affiliation(s)
- Núria Oliveras-Cañellas
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain
| | - Jessica Latorre
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain
| | - Elena Santos-González
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain
| | - Aina Lluch
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain
| | - Francisco Ortega
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain
| | - Jordi Mayneris-Perxachs
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain
| | - José-Manuel Fernández-Real
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain; Department of Medicine, Universitat de Girona, Girona, Spain.
| | - José María Moreno-Navarrete
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomèdica de Girona (IdIBGi), CIBEROBN (CB06/03/010) and Instituto de Salud Carlos III (ISCIII), Girona, Spain.
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4
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Buisson C, Leuzy V, Loizon E, Meugnier E, Monnoye M, Philippe C, Gérard P, Michalski MC, Laugerette F. Soy Lecithin in High-Fat Diets Exerts Dual Effects on Adipose Tissue Versus Ileum. Mol Nutr Food Res 2023; 67:e2200461. [PMID: 36708587 DOI: 10.1002/mnfr.202200461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 01/10/2023] [Indexed: 01/30/2023]
Abstract
SCOPE Lipopolysaccharides and their transporters, LBP and sCD14, are involved in systemic inflammation following a high-fat diet. Natural emulsifiers such as soy lecithin, rich in soybean polar lipids (SPL), are often used by the food industry but little is known about effects of associating SPL with different oils. METHODS AND RESULTS Thus, this study investigates the effects of 4 weeks feeding of palm (P) or rapeseed (R) oil-enriched diets with or without SPL in mice, on white adipose tissue (WAT) inflammation, on ileum permeability, and on microbiota composition. When SPL are associated with rapeseed oil, a greater gene expression of leptin and inflammation in WAT is observed compared to P-SPL. In ileum, R-SPL group results in a lower expression of TLR4, IAP that detoxify bacterial LPS and tight junction proteins than R group. In turn, the gene expression of Reg3β and Reg3γ, which have antimicrobial activity, is higher in ileum of R-SPL group than in R group. SPL in rapeseed oil increases specific bacterial species belonging to Lachnospiraceae, Alistipes, and Bacteroidales. CONCLUSION The incorporation of SPL in a diet with rapeseed oil exerts differential effect on WAT and ileum, with respectively an inflammation of WAT and an antimicrobial activity in ileum, associated with specific microbiota changes.
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Affiliation(s)
- Charline Buisson
- Univ Lyon, CarMeN laboratory INRAE, UMR1397, INSERM, U1060, Université Claude Bernard Lyon 1, Pierre Bénite, 69310, France
| | - Valentin Leuzy
- Univ Lyon, CarMeN laboratory INRAE, UMR1397, INSERM, U1060, Université Claude Bernard Lyon 1, Pierre Bénite, 69310, France
| | - Emmanuelle Loizon
- Univ Lyon, CarMeN laboratory INRAE, UMR1397, INSERM, U1060, Université Claude Bernard Lyon 1, Pierre Bénite, 69310, France
| | - Emmanuelle Meugnier
- Univ Lyon, CarMeN laboratory INRAE, UMR1397, INSERM, U1060, Université Claude Bernard Lyon 1, Pierre Bénite, 69310, France
| | - Magali Monnoye
- Micalis Institute, Université Paris-Saclay, INRAE, AgroParisTech, Jouy-en-Josas, 78350, France
| | - Catherine Philippe
- Micalis Institute, Université Paris-Saclay, INRAE, AgroParisTech, Jouy-en-Josas, 78350, France
| | - Philippe Gérard
- Micalis Institute, Université Paris-Saclay, INRAE, AgroParisTech, Jouy-en-Josas, 78350, France
| | - Marie-Caroline Michalski
- Univ Lyon, CarMeN laboratory INRAE, UMR1397, INSERM, U1060, Université Claude Bernard Lyon 1, Pierre Bénite, 69310, France.,CRNH Rhône-Alpes, Oullins, 69310, France
| | - Fabienne Laugerette
- Univ Lyon, CarMeN laboratory INRAE, UMR1397, INSERM, U1060, Université Claude Bernard Lyon 1, Pierre Bénite, 69310, France
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Enzyme-digested Colla Corii Asini (E'jiao) suppresses lipopolysaccharide-induced inflammatory changes in THP-1 macrophages and OP9 adipocytes. Hum Cell 2022; 35:885-895. [PMID: 35359251 DOI: 10.1007/s13577-022-00694-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 03/23/2022] [Indexed: 01/23/2023]
Abstract
Gut microbial lipopolysaccharides (LPS)-induced inflammatory responses in adipose tissue are associated with the dysfunction of adipocytes, insulin resistance and the development of metabolic syndrome. The aim of this study is to investigate (1) the effects of LPS on the differentiation and inflammatory responses of THP-1 monocytes and OP9 preadipocytes under serum free conditions and (2) the repressive effects of enzyme-digested Colla Corii Asini (CCAD) and fish gelatin (FGD) on LPS-induced inflammatory responses in THP-1 macrophages and OP9 adipocytes. Immunofluorescence and oil red O staining showed that a serum free medium supplied with phorbol 12-myristate 13-acetate (PMA) could induce differentiation and lipid accumulation in THP-1 cells as well as OP9 cells. ELISA showed that LPS significantly increased interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) secretions in PMA-differentiated THP-1 macrophages in a dose-dependent manner. LPS significantly suppressed lipid accumulation and adiponectin secretions, and enhanced IL-6 secretions in OP9 adipocytes. Both CCAD and FGD significantly reduced the levels of both macrophages- and adipocytes-derived inflammatory cytokines and increased the level of OP9-secreted adiponectin. In conclusion, LPS could induce inflammatory responses in both THP-1 and OP9 cells and cause dysfunction of OP9 adipocytes under the serum free conditions. CCAD and FGD can repress LPS-induced inflammatory responses in both THP-1 macrophages and OP9 adipocytes, and increase the secretion of adiponectin in OP9 adipocytes. They could be used as health care supplements for improving metabolic syndrome.
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Jakkawanpitak C, Inafuku M, Oku H, Hutadilok-Towatana N, Bunkrongcheap R, Sermwittayawong N, Aiemchareon P, Sermwittayawong D. Mechanism of the fungal-like particles in the inhibition of adipogenesis in 3T3-L1 adipocytes. Sci Rep 2021; 11:18869. [PMID: 34552185 PMCID: PMC8458348 DOI: 10.1038/s41598-021-98385-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 09/01/2021] [Indexed: 02/08/2023] Open
Abstract
The dynamic ability of adipocytes in adipose tissue to store lipid in response to changes in the nutritional input and inflammatory elicitors has a major impact on human health. Previously, we established laminarin-coated beads or LCB as an inflammatory elicitor for adipocytes. However, it was not clear whether LCB inhibits lipid accumulation in adipocytes. Here, we show that LCB acts in the early stage of adipogenesis through both interleukin-1 receptor-associated kinases (IRAK) and spleen tyrosine kinase (SYK) pathways, resulting in the activation of the AMP-activated protein kinase (AMPK) and nuclear factor-κB (NF-κB) complexes, which subsequently cause cell cycle arrest, downregulation of the key transcription factors and enzymes responsible for adipogenesis, inhibition of adipogenesis, and stimulation of an inflammatory response. While LCB could effectively block lipid accumulation during the early stage of adipogenesis, it could stimulate an inflammatory response at any stage of differentiation. Additionally, our results raise a possibility that toll-like receptor 2 (TLR2) and C-type lectin domain family 7 member A (CLEC7A/Dectin-1) might be potential β-glucan receptors on the fat cells. Together, we present the mechanism of LCB, as fungal-like particles, that elicits an inflammatory response and inhibits adipogenesis at the early stage of differentiation.
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Affiliation(s)
- Chanawee Jakkawanpitak
- Division of Health and Applied Sciences, Faculty of Science, Prince of Songkla University, Hat Yai, 90110, Songkhla, Thailand
| | - Masashi Inafuku
- Faculty of Agriculture, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa, 903-0213, Japan
| | - Hirosuke Oku
- Molecular Biotechnology Group, Center of Molecular Biosciences, Tropical Biosphere Research Center, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa, 903-0213, Japan
| | - Nongporn Hutadilok-Towatana
- Division of Health and Applied Sciences, Faculty of Science, Prince of Songkla University, Hat Yai, 90110, Songkhla, Thailand
| | - Ruthaiwan Bunkrongcheap
- College of Innovation and Management, Songkhla Rajabhat University, Muang District, Songkhla, 90000, Thailand
| | - Natthawan Sermwittayawong
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, 90110, Songkhla, Thailand
| | - Piyapat Aiemchareon
- Division of Health and Applied Sciences, Faculty of Science, Prince of Songkla University, Hat Yai, 90110, Songkhla, Thailand
- Functional Food and Nutrition Program, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, 90110, Songkhla, Thailand
| | - Decha Sermwittayawong
- Division of Health and Applied Sciences, Faculty of Science, Prince of Songkla University, Hat Yai, 90110, Songkhla, Thailand.
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7
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Taghizad F, Kazerani HR, Dehghani H, Asoodeh A, Yaghubi D. A novel approach towards obesity: The use of a bacterial product, gassericin A, in 3T3-L1 cells. Obes Res Clin Pract 2021; 15:499-505. [PMID: 34474970 DOI: 10.1016/j.orcp.2021.08.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 08/21/2021] [Accepted: 08/23/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND AND OBJECTIVE The problem of obesity and its related complications are adversely affecting human society. We studied the effects of gassericin A, a bacteriocin produced by the intestinal bacteria, on adipocyte differentiation and development. DESIGN Gassericin A was purified from Lactobacillus gasseri LA39 and was added to the culture medium of 3T3-L1 cells in two phases: Phase 1, 3T3-L1 cells were incubated with gassericin A while being induced to adipocytes (days 1-7); phase 2, the cells were incubated with the bacteriocin after being induced to adipocytes (days 8-12). The resultant changes in the pattern of expression of some of the important genes involved in adipogenesis were evaluated by RT-qPCR. The viability of cells and their numbers were also studied. RESULTS In phase 1 of the study, the levels of transcripts for stearoyl CoA desaturase (SCD-1), zinc finger protein 423 (zfp-423), and glucose transporter 4 (GLUT4) genes were significantly reduced, while that of 422ap2 gene showed a significant increment (p < 0.05). In phase 2, the zfp-423 gene showed a reduction of expression and the 422ap2 gene showed an increase in expression (p < 0.05). The other genes including UCP-1 and TNF-α did not show any significant changes in neither of the groups. Gassericin A did not affect the morphology or viability of the cells, however, the numbers of cells had nearly doubled in the treatment groups. CONCLUSION It seems that gassericin A could significantly alter the properties of adipocytes while they are in the process of development and after they have developed.
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Affiliation(s)
- Fereidoun Taghizad
- Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Hamid Reza Kazerani
- Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran.
| | - Hesam Dehghani
- Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran; Division of Biotechnology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran; Stem Cell Biology and Regenerative Medicine Research Group, Research Institute of Biotechnology, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Ahmad Asoodeh
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Danial Yaghubi
- Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
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McKernan K, Varghese M, Patel R, Singer K. Role of TLR4 in the induction of inflammatory changes in adipocytes and macrophages. Adipocyte 2020; 9:212-222. [PMID: 32403975 PMCID: PMC7238871 DOI: 10.1080/21623945.2020.1760674] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
In obesity, high levels of saturated fatty acids (SFAs) contribute to adipose tissue inflammation and dysfunction. Obesity-induced macrophage infiltration leads to insulin resistance, but the adipocyte itself may play a role in generating the inflammatory milieu. Given our recent findings of the role of TLR4 in myeloid biasing in obesity, we next investigated the role of TLR4 in adipocyte generated inflammatory responses to SFAs and lipopolysaccharides. We used WT and Tlr4-/- ear mesenchymal stem cell derived adipocytes (EMSC Ad) and bone marrow dendritic cells (BMDCs) to evaluate cell specific responses. Our work demonstrates a role for TLR4 in adipocyte- immune cell crosstalk and that SFA derived metabolites from adipocytes may induce proinflammatory stimulation of immune cells in a TLR4 independent manner.
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Affiliation(s)
- K. McKernan
- Department of Pediatrics and Communicable Disease, University of Michigan Medical School, Ann Arbor, MI, USA
| | - M. Varghese
- Department of Pediatrics and Communicable Disease, University of Michigan Medical School, Ann Arbor, MI, USA
| | - R. Patel
- Department of Pediatrics and Communicable Disease, University of Michigan Medical School, Ann Arbor, MI, USA
| | - K. Singer
- Department of Pediatrics and Communicable Disease, University of Michigan Medical School, Ann Arbor, MI, USA
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9
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Jakkawanpitak C, Hutadilok-Towatana N, Sermwittayawong D. Fungal-like particles and macrophage-conditioned medium are inflammatory elicitors for 3T3-L1 adipocytes. Sci Rep 2020; 10:9437. [PMID: 32523023 PMCID: PMC7287055 DOI: 10.1038/s41598-020-66283-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 05/18/2020] [Indexed: 11/09/2022] Open
Abstract
Adipocytes from white-adipose tissue are known to produce inflammatory cytokines, which play a major role in energy balance and metabolism. While they can respond to pathogen-associated molecular pattern (PAMPs) such as lipopolysaccharide (LPS) from bacteria, it is not known whether adipocytes can be stimulated by fungal cells. Previously, adipocytes were shown to produce toll-like receptor 2 (TLR2), a β-glucan receptor, suggesting that they could respond to β-glucan on the fungal cell wall. In this study, we show that heat-killed yeast induce an inflammatory response in adipocytes. Using fungal-like particles, namely laminarin-coated beads (LCB), we find that these particles trigger the expression of many key inflammatory genes in dose- and time-dependent fashions in adipocytes. These results suggest that β-glucan on the fungal cell wall is sufficient to elicit an inflammatory response in adipocytes. In addition, we show that both LCB and LCB-treated conditioned medium from RAW 264.7 murine macrophages (LCB-RM) induce the expression of those inflammatory genes through IKKβ-IκBα proteins. Together, we conclude that the fungal-like particles and the conditioned medium elicit an inflammatory response in adipocytes through the canonical or classical NF-κB pathway.
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Affiliation(s)
- Chanawee Jakkawanpitak
- Department of Biochemistry, Faculty of Science, Prince of Songkla University, Hat Yai, 90110, Thailand
| | | | - Decha Sermwittayawong
- Department of Biochemistry, Faculty of Science, Prince of Songkla University, Hat Yai, 90110, Thailand.
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10
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Jin K, Ma Y, Manrique-Caballero CL, Li H, Emlet DR, Li S, Baty CJ, Wen X, Kim-Campbell N, Frank A, Menchikova EV, Pastor-Soler NM, Hallows KR, Jackson EK, Shiva S, Pinsky MR, Zuckerbraun BS, Kellum JA, Gómez H. Activation of AMP-activated protein kinase during sepsis/inflammation improves survival by preserving cellular metabolic fitness. FASEB J 2020; 34:7036-7057. [PMID: 32246808 DOI: 10.1096/fj.201901900r] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 01/24/2020] [Accepted: 03/18/2020] [Indexed: 01/08/2023]
Abstract
The purpose was to determine the role of AMPK activation in the renal metabolic response to sepsis, the development of sepsis-induced acute kidney injury (AKI) and on survival. In a prospective experimental study, 167 10- to 12-week-old C57BL/6 mice underwent cecal ligation and puncture (CLP) and human proximal tubule epithelial cells (TEC; HK2) were exposed to inflammatory mix (IM), a combination of lipopolysaccharide (LPS) and high mobility group box 1 (HMGB1). Renal/TEC metabolic fitness was assessed by monitoring the expression of drivers of oxidative phosphorylation (OXPHOS), the rates of utilization of OXPHOS/glycolysis in response to metabolic stress, and mitochondrial function by measuring O2 consumption rates (OCR) and the membrane potential (Δψm ). Sepsis/IM resulted in AKI, increased mortality, and in renal AMPK activation 6-24 hours after CLP/IM. Pharmacologic activation of AMPK with 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) or metformin during sepsis improved the survival, while AMPK inhibition with Compound C increased mortality, impaired mitochondrial respiration, decreased OCR, and disrupted TEC metabolic fitness. AMPK-driven protection was associated with increased Sirt 3 expression and restoration of metabolic fitness. Renal AMPK activation in response to sepsis/IM is an adaptive mechanism that protects TEC, organs, and the host by preserving mitochondrial function and metabolic fitness likely through Sirt3 signaling.
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Affiliation(s)
- Kui Jin
- Department of Critical Care, Anhui Provincial Hospital, He Fei, China
| | - Yujie Ma
- Department of Critical Care Medicine, Air Force Medical Center, Beijing, China
| | - Carlos L Manrique-Caballero
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hui Li
- Division of Nephrology and Hypertension and USC/UKRO Kidney Research Center, Department of Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| | - David R Emlet
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shengnan Li
- Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Catherine J Baty
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Xiaoyan Wen
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nahmah Kim-Campbell
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alicia Frank
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Elizabeth V Menchikova
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nuria M Pastor-Soler
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA.,Division of Nephrology and Hypertension and USC/UKRO Kidney Research Center, Department of Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| | - Kenneth R Hallows
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA.,Division of Nephrology and Hypertension and USC/UKRO Kidney Research Center, Department of Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| | - Edwin K Jackson
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sruti Shiva
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.,Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael R Pinsky
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Brian S Zuckerbraun
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - John A Kellum
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hernando Gómez
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA.,Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
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11
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Controls of Nuclear Factor-Kappa B Signaling Activity by 5'-AMP-Activated Protein Kinase Activation With Examples in Human Bladder Cancer Cells. Int Neurourol J 2016; 20:182-187. [PMID: 27706018 PMCID: PMC5083836 DOI: 10.5213/inj.1632718.359] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 09/26/2016] [Indexed: 02/02/2023] Open
Abstract
Generally, both lipopolysaccharide (LPS)- and hypoxia-induced nuclear factor kappa B (NF-κB) effects are alleviated through differential posttranslational modification of NF-κB phosphorylation after pretreatment with 5´-AMP-activated protein kinase (AMPK) activators such as 5´-aminoimidazole-4-carboxamide ribonucleotide (AICAR) or the hypoglycemic agent metformin. We found that AICAR or metformin acts as a regulator of LPS/NF-κB-or hypoxia/NF-κB-mediated cyclooxygenase induction by an AMPK-dependent mechanism with interactions between p65-NF-κB phosphorylation and acetylation, including in a human bladder cancer cell line (T24). In summary, we highlighted the regulatory interactions of AMPK activity on NF-κB induction, particularly in posttranslational phosphorylation and acetylation of NF-κB under inflammatory conditions or hypoxia environment.
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12
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Kusuyama J, Komorizono A, Bandow K, Ohnishi T, Matsuguchi T. CXCL3 positively regulates adipogenic differentiation. J Lipid Res 2016; 57:1806-1820. [PMID: 27512010 DOI: 10.1194/jlr.m067207] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Indexed: 12/19/2022] Open
Abstract
Chemokines are a family of cytokines inducing cell migration and inflammation. Recent reports have implicated the roles of chemokines in cell differentiation. However, little is known about the functional roles of chemokines in adipocytes. Here, we explored gene expression levels of chemokines and chemokine receptors during adipogenic differentiation. We have found that two chemokines, chemokine (C-X-C motif) ligand 3 (CXCL3) and CXCL13, as well as CXC chemokine receptor 2 (CXCR2), a CXCL3 receptor, are highly expressed in mature adipocytes. When 3T3-L1 cells and ST2 cells were induced to differentiate, both the number of lipid droplets and the expression levels of adipogenic markers were significantly promoted by the addition of CXCL3, but not CXCL13. Conversely, gene knockdown of either CXCL3 or CXCR2 by specific siRNA effectively inhibited the course of adipogenic differentiation. CXCL3 treatment of 3T3-L1 cells significantly induced the phosphorylation of ERK and c-jun N-terminal kinase (JNK). Furthermore, CXCL3-induced CCAAT-enhancer binding protein (C/EBP)β and δ expression was suppressed by both ERK and JNK-specific inhibitors. Furthermore, chromatin immunoprecipitation assay revealed functional binding of PPARγ2 within the cxcl3 promoter region. Taken together, these results have indicated that CXCL3 is a novel adipokine that facilitates adipogenesis in an autocrine and/or a paracrine manner through induction of c/ebpb and c/ebpd.
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Affiliation(s)
- Joji Kusuyama
- Department of Oral Biochemistry, Field of Developmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Anna Komorizono
- Department of Oral Biochemistry, Field of Developmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Kenjiro Bandow
- Department of Oral Biology and Tissue Engineering, Meikai University School of Dentistry, Saitama, Japan
| | - Tomokazu Ohnishi
- Department of Oral Biochemistry, Field of Developmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Tetsuya Matsuguchi
- Department of Oral Biochemistry, Field of Developmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
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13
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Zhou ZY, Ren LW, Zhan P, Yang HY, Chai DD, Yu ZW. Metformin exerts glucose-lowering action in high-fat fed mice via attenuating endotoxemia and enhancing insulin signaling. Acta Pharmacol Sin 2016; 37:1063-75. [PMID: 27180982 DOI: 10.1038/aps.2016.21] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 03/08/2016] [Indexed: 12/13/2022] Open
Abstract
AIM Accumulating evidence shows that lipopolysaccharides (LPS) derived from gut gram-negative bacteria can be absorbed, leading to endotoxemia that triggers systemic inflammation and insulin resistance. In this study we examined whether metformin attenuated endotoxemia, thus improving insulin signaling in high-fat diet fed mice. METHODS Mice were fed a high-fat diet for 18 weeks to induce insulin resistance. One group of the mice was treated with oral metformin (100 mg·kg(-1)·d(-1)) for 4 weeks. Another group was treated with LPS (50 μg·kg(-1)·d(-1), sc) for 5 days followed by the oral metformin for 10 d. Other two groups received a combination of antibiotics for 7 d or a combination of antibiotics for 7 d followed by the oral metformin for 4 weeks, respectively. Glucose metabolism and insulin signaling in liver and muscle were evaluated, the abundance of gut bacteria, gut permeability and serum LPS levels were measured. RESULTS In high-fat fed mice, metformin restored the tight junction protein occludin-1 levels in gut, reversed the elevated gut permeability and serum LPS levels, and increased the abundance of beneficial bacteria Lactobacillus and Akkermansia muciniphila. Metformin also increased PKB Ser473 and AMPK T172 phosphorylation, decreased MDA contents and redox-sensitive PTEN protein levels, activated the anti-oxidative Nrf2 system, and increased IκBα in liver and muscle of the mice. Treatment with exogenous LPS abolished the beneficial effects of metformin on glucose metabolism, insulin signaling and oxidative stress in liver and muscle of the mice. Treatment with antibiotics alone produced similar effects as metformin did. Furthermore, the beneficial effects of antibiotics were addictive to those of metformin. CONCLUSION Metformin administration attenuates endotoxemia and enhances insulin signaling in high-fat fed mice, which contributes to its anti-diabetic effects.
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14
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Wang X, Hai C. Redox modulation of adipocyte differentiation: hypothesis of "Redox Chain" and novel insights into intervention of adipogenesis and obesity. Free Radic Biol Med 2015; 89:99-125. [PMID: 26187871 DOI: 10.1016/j.freeradbiomed.2015.07.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 06/19/2015] [Accepted: 07/08/2015] [Indexed: 02/08/2023]
Abstract
In view of the global prevalence of obesity and obesity-associated disorders, it is important to clearly understand how adipose tissue forms. Accumulating data from various laboratories implicate that redox status is closely associated with energy metabolism. Thus, biochemical regulation of the redox system may be an attractive alternative for the treatment of obesity-related disorders. In this work, we will review the current data detailing the role of the redox system in adipocyte differentiation, as well as identifying areas for further research. The redox system affects adipogenic differentiation in an extensive way. We propose that there is a complex and interactive "redox chain," consisting of a "ROS-generating enzyme chain," "combined antioxidant chain," and "transcription factor chain," which contributes to fine-tune the regulation of ROS level and subsequent biological consequences. The roles of the redox system in adipocyte differentiation are paradoxical. The redox system exerts a "tridimensional" mechanism in the regulation of adipocyte differentiation, including transcriptional, epigenetic, and posttranslational modulations. We suggest that redoxomic techniques should be extensively applied to understand the biological effects of redox alterations in a more integrated way. A stable and standardized "redox index" is urgently needed for the evaluation of the general redox status. Therefore, more effort should be made to establish and maintain a general redox balance rather than to conduct simple prooxidant or antioxidant interventions, which have comprehensive implications.
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Affiliation(s)
- Xin Wang
- Department of Toxicology, Shaanxi Key Lab of Free Radical Biology and Medicine, the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an, 710032, China.
| | - Chunxu Hai
- Department of Toxicology, Shaanxi Key Lab of Free Radical Biology and Medicine, the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an, 710032, China.
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15
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Zhao M, Chen X. Effect of lipopolysaccharides on adipogenic potential and premature senescence of adipocyte progenitors. Am J Physiol Endocrinol Metab 2015; 309:E334-44. [PMID: 26105007 PMCID: PMC4537924 DOI: 10.1152/ajpendo.00601.2014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 06/22/2015] [Indexed: 01/13/2023]
Abstract
The elevation of circulating LPS has been associated with obesity and aging. However, whether and how LPS contributes to adipose tissue dysfunction is unclear. In this study, we investigated the effect of LPS on the adipogenic capacity and cellular senescence of adipocyte progenitors. Stromal-vascular cells were isolated from inguinal adipose tissue of C57BL/6 mice and treated with LPS during the different time periods of adipocyte differentiation. We found that LPS treatment for 24 h prior to the induction of differentiation led to the most profound effect on the inhibition of adipogenesis, as evidenced by the morphological changes and the decreased mRNA expression of adipocyte marker genes. In addition, LPS induced features of premature senescence of SV cells, including the activation of p53, the elevation of SA-β-gal activity, and increased hydrogen peroxide production, but not telomere length. Upon LPS treatment, SV cells also developed senescence-associated secretory phenotype (SASP), as demonstrated by the increased expression of TNFα, IL-1β, IL-6, MCP-1, and VEGFα. Blocking LPS-induced NF-κB activation and cytokine production by Bay 11-7082 failed to rescue the impaired adipogenesis and the reduction in PPARγ and Zfp423 expression. On the contrary, rosiglitazone had little effect on cytokine production but corrected the defective adipogenic potential. In conclusion, we demonstrate that LPS inhibits adipogenesis by disrupting the differentiation of adipocyte progenitors in a NF-κB-independent manner; LPS also induces premature senescence of adipocyte progenitors. Our data suggest that LPS could be a potential contributor to the defective adipogenesis and the development of cellular senescence in adipose tissue during obesity and aging.
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Affiliation(s)
- Ming Zhao
- Department of Food Science and Nutrition, University of Minnesota-Twin Cities, St. Paul, Minnesota
| | - Xiaoli Chen
- Department of Food Science and Nutrition, University of Minnesota-Twin Cities, St. Paul, Minnesota
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16
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Abstract
Obesity is associated with altered gut microbiota composition and impaired gut barrier function. These changes, together with interrelated mesenteric adipose tissue inflammation, result in increased release of pro-inflammatory cytokines, bacteria-derived factors, and lipids into the portal circulation, promoting the development of (hepatic) insulin resistance. Herein, the potential impact of obesity-related changes in gut and visceral adipose tissue biology on the development of insulin resistance and Type 2 diabetes is reviewed.
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Affiliation(s)
- Daniel Konrad
- Department of Pediatric Endocrinology and Diabetology, University Children's Hospital, Zurich, Switzerland; Children's Research Center, University Children's Hospital, Zurich, Switzerland; and Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Stephan Wueest
- Department of Pediatric Endocrinology and Diabetology, University Children's Hospital, Zurich, Switzerland; Children's Research Center, University Children's Hospital, Zurich, Switzerland; and
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17
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Moreira APB, Alves RDM, Teixeira TFS, Macedo VS, de Oliveira LL, Costa NMB, Bressan J, do Carmo Gouveia Peluzio M, Mattes R, de Cássia Gonçalves Alfenas R. Higher plasma lipopolysaccharide concentrations are associated with less favorable phenotype in overweight/obese men. Eur J Nutr 2014; 54:1363-70. [PMID: 25519002 DOI: 10.1007/s00394-014-0817-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 12/09/2014] [Indexed: 01/21/2023]
Abstract
PURPOSE Lipopolysaccharide (LPS) from the outer membrane of gram-negative bacteria might be an inflammation trigger in adipose tissue. It has recently been proposed that there is a link between adipose tissue distribution and blood LPS. However, the number of studies on this topic is scarce, and further investigation in humans is required. In this study, we explored the association between plasma LPS concentrations and body fat distribution, as well as the biochemical parameters that may indicate the presence of metabolic disorders. METHODS Sixty-seven young adult men with body mass index of 26-35 kg/m(2) were evaluated. Anthropometry, body composition and body fat distribution, blood pressure, energy expenditure, physical activity level, dietary intake, and biochemical parameters were assessed. RESULTS Men with median plasma LPS ≥ 0.9 EU/mL presented higher sagittal abdominal diameter, trunk fat percentage, and android fat percentage, and mass, insulin and alanine aminotransferase concentrations, homeostasis model assessment of insulin resistance (HOMA-IR), and beta cell dysfunction (HOMA-B) than those with lower plasma LPS. LPS correlated positively with the trunk fat percentage, and android fat percentage, and mass, insulin, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase concentrations, as well as HOMA-IR and HOMA-B. CONCLUSION Our results suggest that a higher plasma LPS concentration is associated with a less favorable phenotype as characterized by higher central adiposity, higher values of HOMA-IR, and beta cell function impairment in overweight/obese men.
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Affiliation(s)
- Ana Paula Boroni Moreira
- Departamento de Nutrição, Universidade Federal de Juiz de Fora, Bairro Martelos, s/n, Juiz de Fora, Minas Gerais, CEP 36036-330, Brazil.
| | | | | | - Viviane Silva Macedo
- Department of Nutrition and Health, Universidade Federal de Viçosa, Viçosa, Brazil
| | | | | | - Josefina Bressan
- Department of Nutrition and Health, Universidade Federal de Viçosa, Viçosa, Brazil
| | | | - Richard Mattes
- Department of Foods and Nutrition, Purdue University, West Lafayette, IN, USA
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18
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Ellagic Acid Reduces Adipogenesis through Inhibition of Differentiation-Prevention of the Induction of Rb Phosphorylation in 3T3-L1 Adipocytes. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:287534. [PMID: 24302962 PMCID: PMC3835195 DOI: 10.1155/2013/287534] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 09/07/2013] [Accepted: 09/09/2013] [Indexed: 01/16/2023]
Abstract
Ellagic acid (EA) present in many fruits and nuts serves as antiproliferation, anti-inflammatory, and antitumorigenic properties. However, the effect of EA on preadipocytes adipogenesis and its mechanism(s) have not been elucidated. The present study was designed to examine the effect of EA on adipogenesis in 3T3-L1 preadipocytes and underlying mechanism(s) of action involved. Data show that EA administration decreased the accumulation of lipid droplets. The inhibition was diminished when the addition of EA was delayed to days 2–4 of differentiation. Clonal expansion was reduced in the presence of EA. FACS analysis showed that EA blocked the cell cycle at the G1/S transition. EdU incorporation also confirmed that EA refrained cell from entering S phase. Our data also revealed that the differentiation-induced protein expression of Cyclin A and phosphorylation of the retinoblastoma protein (Rb) were impaired by EA. Differentiation-dependent expression and DNA-binding ability of C/EBPα were also inhibited by EA. Alterations in cell cycle-associated proteins may be important with respect to the antiadipogenic action of EA. In conclusion, EA is capable of inhibiting adipogenesis in 3T3-L1 adipocytes possibly through reduction of Cyclin A protein expression and Rb phosphorylation. With the blocking of G1/S phase transition, EA suppresses terminal differentiation and lipid accumulation in 3T3-L1 adipocytes.
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19
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Luche E, Cousin B, Garidou L, Serino M, Waget A, Barreau C, André M, Valet P, Courtney M, Casteilla L, Burcelin R. Metabolic endotoxemia directly increases the proliferation of adipocyte precursors at the onset of metabolic diseases through a CD14-dependent mechanism. Mol Metab 2013; 2:281-91. [PMID: 24049740 DOI: 10.1016/j.molmet.2013.06.005] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Revised: 06/18/2013] [Accepted: 06/21/2013] [Indexed: 01/17/2023] Open
Abstract
Metabolic endotoxemia triggers inflammation, targets cells from the stroma-vascular fraction of adipose depots, and metabolic disease. To identify these cells we here infused mice with lipopolysaccharides and showed by FACS analyses and BrdU staining that the number of small subcutaneous adipocytes, preadipocytes and macrophages increased in wild type but not in CD14-knockout (KO) mice. This mechanism was direct since in CD14KO mice grafted subcutaneously and simultaneously with fat pads from CD14KO and wild-type mice the concentration of cytokine mRNA was increased in the wild-type fat pad only. Conversely, the mRNA concentration of genes involved in glucose and lipid metabolism and the number of large adipocytes was reduced. Eventually, a pretreatment with LPS enhanced HFD-induced metabolic diseases. Altogether, these results show that metabolic endotoxemia increases the proliferation of preadipocytes through a CD14-dependent mechanism directly, without recruiting CD14-positive cells from non-adipose depot origin. This mechanism could precede the onset of metabolic diseases.
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Affiliation(s)
- Elodie Luche
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1048, Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Toulouse, France ; Université Paul Sabatier, Toulouse, France
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