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Zhang Y, Shen T, Wang S. Progression from prediabetes to type 2 diabetes mellitus induced by overnutrition. Hormones (Athens) 2022; 21:591-597. [PMID: 36197636 DOI: 10.1007/s42000-022-00399-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 09/19/2022] [Indexed: 12/31/2022]
Abstract
Prediabetes has developed into a global pandemic, its prevalence increasing year by year. Although lifestyle changes are advocated as the basis for prediabetes treatment, some patients fail to choose or adhere to appropriate interventions. The basis for selecting an appropriate intervention is determining the stage and cause of the disease. In this review, we aimed to examine the various types and disease processes of prediabetes caused by overnutrition, the present review supporting the hypothesis that overnutrition-induced hyperinsulinemia precedes insulin resistance (IR) and independently causes β-cell dysfunction. Tissue insulin resistance is the main feature of prediabetes with the crosstalk between tissues promoting the formation of systemic insulin resistance. Finally, both β-cell dysfunction induced by hyperinsulinemia or IR and reduced β-cell mass can lead to abnormal insulin secretion and contribute to development of type 2 diabetes mellitus (T2DM). Hence, overnutrition can cause multiple prediabetes phenotypes resulting in development of T2DM through different trajectories. Future diagnosis and treatment should therefore more carefully consider the disease phenotype and stage of development in patients with prediabetes to reduce the incidence of T2DM.
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Affiliation(s)
- Yuli Zhang
- School of Physical Education & Sports Science, South China Normal University, No.55, West of Zhongshan Ave., Tianhe District, Guangzhou City, 510006, Guangdong Province, China
| | - Tuming Shen
- School of Physical Education & Sports Science, South China Normal University, No.55, West of Zhongshan Ave., Tianhe District, Guangzhou City, 510006, Guangdong Province, China
| | - Songtao Wang
- School of Physical Education & Sports Science, South China Normal University, No.55, West of Zhongshan Ave., Tianhe District, Guangzhou City, 510006, Guangdong Province, China.
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Menendez A, Wanczyk H, Walker J, Zhou B, Santos M, Finck C. Obesity and Adipose Tissue Dysfunction: From Pediatrics to Adults. Genes (Basel) 2022; 13:genes13101866. [PMID: 36292751 PMCID: PMC9601855 DOI: 10.3390/genes13101866] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/27/2022] [Accepted: 10/14/2022] [Indexed: 11/04/2022] Open
Abstract
Obesity is a growing health problem that affects both children and adults. The increasing prevalence of childhood obesity is associated with comorbidities such as cardiovascular disease, type 2 diabetes and metabolic syndrome due to chronic low-grade inflammation present at early stages of the disease. In pediatric patients suffering from obesity, the role of epigenetics, the gut microbiome and intrauterine environment have emerged as causative factors Interestingly, pediatric obesity is strongly associated with low birth weight. Accelerated weight gain oftentimes occurs in these individuals during the post-natal period, which can lead to increased risk of adiposity and metabolic disease. The pathophysiology of obesity is complex and involves biological and physiological factors compounded by societal factors such as family and community. On a cellular level, adipocytes contained within adipose tissue become dysregulated and further contribute to development of comorbidities similar to those present in adults with obesity. This review provides an overview of the current understanding of adipose tissue immune, inflammatory and metabolic adaptation of the adipose tissue in obesity. Early cellular changes as well as the role of immune cells and inflammation on the progression of disease in pivotal pediatric clinical trials, adult studies and mouse models are emphasized. Understanding the initial molecular and cellular changes that occur during obesity can facilitate new and improved treatments aimed at early intervention and subsequent prevention of adulthood comorbidities.
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Affiliation(s)
- Ana Menendez
- Connecticut Children’s Medical Center, Department of Pediatric Endocrinology, Hartford, CT 06106, USA
| | - Heather Wanczyk
- University of Connecticut Health Center, Department of Pediatrics, Farmington, CT 06030, USA
| | - Joanne Walker
- University of Connecticut Health Center, Department of Pediatrics, Farmington, CT 06030, USA
| | - Beiyan Zhou
- University of Connecticut Health Center, Department of Immunology, Farmington, CT 06030, USA
| | - Melissa Santos
- Connecticut Children’s Medical Center, Department of Pediatric Psychology and Director of the Obesity Center, Hartford, CT 06106, USA
| | - Christine Finck
- Connecticut Children’s Medical Center, Department of Surgery and Pediatric Bariatric Surgery, Hartford, CT 06106, USA
- Correspondence: ; Tel.: +860-545-9520
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Macrophages, Low-Grade Inflammation, Insulin Resistance and Hyperinsulinemia: A Mutual Ambiguous Relationship in the Development of Metabolic Diseases. J Clin Med 2022; 11:jcm11154358. [PMID: 35955975 PMCID: PMC9369133 DOI: 10.3390/jcm11154358] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 02/06/2023] Open
Abstract
Metabolic derangement with poor glycemic control accompanying overweight and obesity is associated with chronic low-grade inflammation and hyperinsulinemia. Macrophages, which present a very heterogeneous population of cells, play a key role in the maintenance of normal tissue homeostasis, but functional alterations in the resident macrophage pool as well as newly recruited monocyte-derived macrophages are important drivers in the development of low-grade inflammation. While metabolic dysfunction, insulin resistance and tissue damage may trigger or advance pro-inflammatory responses in macrophages, the inflammation itself contributes to the development of insulin resistance and the resulting hyperinsulinemia. Macrophages express insulin receptors whose downstream signaling networks share a number of knots with the signaling pathways of pattern recognition and cytokine receptors, which shape macrophage polarity. The shared knots allow insulin to enhance or attenuate both pro-inflammatory and anti-inflammatory macrophage responses. This supposedly physiological function may be impaired by hyperinsulinemia or insulin resistance in macrophages. This review discusses the mutual ambiguous relationship of low-grade inflammation, insulin resistance, hyperinsulinemia and the insulin-dependent modulation of macrophage activity with a focus on adipose tissue and liver.
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Scordamaglia D, Cirillo F, Talia M, Santolla MF, Rigiracciolo DC, Muglia L, Zicarelli A, De Rosis S, Giordano F, Miglietta AM, De Francesco EM, Vella V, Belfiore A, Lappano R, Maggiolini M. Metformin counteracts stimulatory effects induced by insulin in primary breast cancer cells. J Transl Med 2022; 20:263. [PMID: 35672854 PMCID: PMC9172136 DOI: 10.1186/s12967-022-03463-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 05/25/2022] [Indexed: 11/13/2022] Open
Abstract
Background Metabolic disorders are associated with increased incidence, aggressive phenotype and poor outcome of breast cancer (BC) patients. For instance, hyperinsulinemia is an independent risk factor for BC and the insulin/insulin receptor (IR) axis is involved in BC growth and metastasis. Of note, the anti-diabetic metformin may be considered in comprehensive therapeutic approaches in BC on the basis of its antiproliferative effects obtained in diverse pre-clinical and clinical studies. Methods Bioinformatics analysis were performed using the information provided by The Invasive Breast Cancer Cohort of The Cancer Genome Atlas (TCGA) project. The naturally immortalized BC cell line, named BCAHC-1, as well as cancer-associated fibroblasts (CAFs) derived from BC patients were used as model systems. In order to identify further mechanisms that characterize the anticancer action of metformin in BC, we performed gene expression and promoter studies as well as western blotting experiments. Moreover, cell cycle analysis, colony and spheroid formation, actin cytoskeleton reorganization, cell migration and matrigel drops evasion assays were carried out to provide novel insights on the anticancer properties of metformin. Results We first assessed that elevated expression and activation of IR correlate with a worse prognostic outcome in estrogen receptor (ER)-positive BC. Thereafter, we established that metformin inhibits the insulin/IR-mediated activation of transduction pathways, gene changes and proliferative responses in BCAHC-1 cells. Then, we found that metformin interferes with the insulin-induced expression of the metastatic gene CXC chemokine receptor 4 (CXCR4), which we found to be associated with poor disease-free survival in BC patients exhibiting high levels of IR. Next, we ascertained that metformin prevents a motile phenotype of BCAHC-1 cells triggered by the paracrine liaison between tumor cells and CAFs upon insulin activated CXCL12/CXCR4 axis. Conclusions Our findings provide novel mechanistic insights regarding the anti-proliferative and anti-migratory effects of metformin in both BC cells and important components of the tumor microenvironment like CAFs. Further investigations are warranted to corroborate the anticancer action of metformin on the tumor mass toward the assessment of more comprehensive strategies halting BC progression, in particular in patients exhibiting metabolic disorders and altered insulin/IR functions. Supplementary Information The online version contains supplementary material available at 10.1186/s12967-022-03463-y.
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Chen HM, Wu CF, Hsieh CJ, Kuo FC, Sun CW, Wang SL, Chen ML, Wu MT. Relationship of maternal body weight and gestational diabetes mellitus with large-for-gestational-age babies at birth in Taiwan: The TMICS cohort. Taiwan J Obstet Gynecol 2022; 61:234-242. [DOI: 10.1016/j.tjog.2022.02.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/27/2021] [Indexed: 10/18/2022] Open
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Palmer TM, Salt IP. Nutrient regulation of inflammatory signalling in obesity and vascular disease. Clin Sci (Lond) 2021; 135:1563-1590. [PMID: 34231841 DOI: 10.1042/cs20190768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 06/10/2021] [Accepted: 06/28/2021] [Indexed: 11/17/2022]
Abstract
Despite obesity and diabetes markedly increasing the risk of developing cardiovascular diseases, the molecular and cellular mechanisms that underlie this association remain poorly characterised. In the last 20 years it has become apparent that chronic, low-grade inflammation in obese adipose tissue may contribute to the risk of developing insulin resistance and type 2 diabetes. Furthermore, increased vascular pro-inflammatory signalling is a key event in the development of cardiovascular diseases. Overnutrition exacerbates pro-inflammatory signalling in vascular and adipose tissues, with several mechanisms proposed to mediate this. In this article, we review the molecular and cellular mechanisms by which nutrients are proposed to regulate pro-inflammatory signalling in adipose and vascular tissues. In addition, we examine the potential therapeutic opportunities that these mechanisms provide for suppression of inappropriate inflammation in obesity and vascular disease.
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Affiliation(s)
- Timothy M Palmer
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull HU6 7RX, United Kingdom
| | - Ian P Salt
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
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Tůma P, Sommerová B, Šiklová M. Monitoring of adipose tissue metabolism using microdialysis and capillary electrophoresis with contactless conductivity detection. Talanta 2019; 192:380-386. [DOI: 10.1016/j.talanta.2018.09.076] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/19/2018] [Accepted: 09/20/2018] [Indexed: 02/02/2023]
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Krauzová E, Tůma P, de Glisezinski I, Štich V, Šiklová M. Metformin Does Not Inhibit Exercise-Induced Lipolysis in Adipose Tissue in Young Healthy Lean Men. Front Physiol 2018; 9:604. [PMID: 29875699 PMCID: PMC5974160 DOI: 10.3389/fphys.2018.00604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 05/04/2018] [Indexed: 01/04/2023] Open
Abstract
Objective: Metformin was shown to exert an antilipolytic action in adipose tissue (AT) that might mediate beneficial effects on lipid metabolism in diabetic patients. However, during exercise, the inhibition of induced lipolysis in AT would limit the energy substrate supply for working muscle. Thus, the aim of this study was to investigate whether metformin exerts inhibitory effect on exercise-induced lipolysis in subcutaneous adipose tissue (SCAT) (Moro et al., 2007) in humans. Approach: Ten healthy lean men underwent two exercise sessions consisting of 60 min of cycling on bicycle ergometer combined with (a) orally administered metformin and (b) metformin locally administered into SCAT. Microdialysis was used to assess lipolysis in situ in SCAT. Glycerol, metformin and lactate were measured in dialysate and plasma by enzyme colorimetric kits and capillary electrophoresis. Results: Metformin levels increased continuously in plasma during 3 h after oral administration, and peaked after 3.5 h (peak concentration 4 μg/ml). Metformin was detected in dialysate outflowing from SCAT and showed a similar time-course as that in plasma with the peak concentration of 1.3 μg/ml. The lipolytic rate in SCAT (assessed as glycerol release) increased in response to exercise (4.3 ± 0.5-fold vs. basal; p = 0.002) and was not suppressed either by local or oral metformin administration. The lactate levels increased in plasma and in dialysate from SCAT after 30-60 min of exercise (3.6-fold vs. basal; p = 0.015; 2.75-fold vs. basal; p = 0.002, respectively). No effect of metformin on lactate levels in SCAT dialysate or in plasma during exercise was observed. Conclusion: Metformin did not reduce the exercise-induced lipolysis in SCAT. This suggests that metformin administration does not interfere with the lipid mobilization and energy substrate provision during physical activity.
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Affiliation(s)
- Eva Krauzová
- Department for the Study of Obesity and Diabetes, Third Faculty of Medicine, Charles University, Prague, Czechia.,Second Department of Internal Medicine, University Hospital Královské Vinohrady, Prague, Czechia
| | - Petr Tůma
- Department of Hygiene, Third Faculty of Medicine, Charles University, Prague, Czechia
| | - Isabelle de Glisezinski
- INSERM, UMR1048, Obesity Research Laboratory, Institute of Metabolic and Cardiovascular Diseases, University of Toulouse, Paul Sabatier University, Toulouse, France.,Department of Clinical Biochemistry and Sports Medicine, Toulouse University Hospital, Toulouse, France
| | - Vladimír Štich
- Department for the Study of Obesity and Diabetes, Third Faculty of Medicine, Charles University, Prague, Czechia.,Second Department of Internal Medicine, University Hospital Královské Vinohrady, Prague, Czechia
| | - Michaela Šiklová
- Department for the Study of Obesity and Diabetes, Third Faculty of Medicine, Charles University, Prague, Czechia
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Insulin action and resistance in obesity and type 2 diabetes. Nat Med 2017; 23:804-814. [PMID: 28697184 DOI: 10.1038/nm.4350] [Citation(s) in RCA: 749] [Impact Index Per Article: 107.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 05/11/2017] [Indexed: 12/12/2022]
Abstract
Nutritional excess is a major forerunner of type 2 diabetes. It enhances the secretion of insulin, but attenuates insulin's metabolic actions in the liver, skeletal muscle and adipose tissue. However, conflicting evidence indicates a lack of knowledge of the timing of these events during the development of obesity and diabetes, pointing to a key gap in our understanding of metabolic disease. This Perspective reviews alternate viewpoints and recent results on the temporal and mechanistic connections between hyperinsulinemia, obesity and insulin resistance. Although much attention has addressed early steps in the insulin signaling cascade, insulin resistance in obesity seems to be largely elicited downstream of these steps. New findings also connect insulin resistance to extensive metabolic cross-talk between the liver, adipose tissue, pancreas and skeletal muscle. These and other advances over the past 5 years offer exciting opportunities and daunting challenges for the development of new therapeutic strategies for the treatment of type 2 diabetes.
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10
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Microdialysis of Large Molecules. J Pharm Sci 2016; 105:3233-3242. [DOI: 10.1016/j.xphs.2016.08.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/01/2016] [Accepted: 08/22/2016] [Indexed: 12/21/2022]
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McCormack WG, Cooke JP, O’Connor WT, Jakeman PM. Dynamic measures of skeletal muscle dialysate and plasma amino acid concentration in response to exercise and nutrient ingestion in healthy adult males. Amino Acids 2016; 49:151-159. [DOI: 10.1007/s00726-016-2343-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 09/29/2016] [Indexed: 12/01/2022]
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Pedersen DJ, Guilherme A, Danai LV, Heyda L, Matevossian A, Cohen J, Nicoloro SM, Straubhaar J, Noh HL, Jung D, Kim JK, Czech MP. A major role of insulin in promoting obesity-associated adipose tissue inflammation. Mol Metab 2015; 4:507-18. [PMID: 26137438 PMCID: PMC4481426 DOI: 10.1016/j.molmet.2015.04.003] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 04/18/2015] [Accepted: 04/22/2015] [Indexed: 12/23/2022] Open
Abstract
Objective Adipose tissue (AT) inflammation is associated with systemic insulin resistance and hyperinsulinemia in obese rodents and humans. A longstanding concept is that hyperinsulinemia may promote systemic insulin resistance through downregulation of its receptor on target tissues. Here we tested the novel hypothesis that insulin also impairs systemic insulin sensitivity by specifically enhancing adipose inflammation. Methods Circulating insulin levels were reduced by about 50% in diet-induced and genetically obese mice by treatments with diazoxide or streptozotocin, respectively. We then examined AT crown-like structures, macrophage markers and pro-inflammatory cytokine expression in AT. AT lipogenesis and systemic insulin sensitivity was also monitored. Conversely, insulin was infused into lean mice to determine its affects on the above parameters. Results Lowering circulating insulin levels in obese mice by streptozotocin treatment decreased macrophage content in AT, enhancing insulin stimulated Akt phosphorylation and de novo lipogenesis (DNL). Moreover, responsiveness of blood glucose levels to injected insulin was improved by streptozotocin and diazoxide treatments of obese mice without changes in body weight. Remarkably, even in lean mice, infusion of insulin under constant euglycemic conditions stimulated expression of cytokines in AT. Consistent with these findings, insulin treatment of 3T3-L1 adipocytes caused a 10-fold increase in CCL2 mRNA levels within 6 h, which was blocked by the ERK inhibitor PD98059. Conclusion Taken together, these results indicate that obesity-associated hyperinsulinemia unexpectedly drives AT inflammation in obese mice, which in turn contributes to factors that suppress insulin-stimulated adipocyte DNL and systemic insulin sensitivity. Adipose tissue inflammation correlates with hyperinsulinemia in obese mice and humans independent of BMI. Reduction of hyperinsulinemia ameliorates adipose tissue inflammation and enhances systemic insulin sensitivity. Insulin increases adipose inflammation in vivo and enhances adipocyte MCP-1 expression in vitro through ERK activation.
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Affiliation(s)
- David J Pedersen
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Adilson Guilherme
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Laura V Danai
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Lauren Heyda
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Anouch Matevossian
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Jessica Cohen
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Sarah M Nicoloro
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Juerg Straubhaar
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Hye Lim Noh
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA ; Division of Endocrinology, Metabolism, and Diabetes, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - DaeYoung Jung
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA ; Division of Endocrinology, Metabolism, and Diabetes, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Jason K Kim
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA ; Division of Endocrinology, Metabolism, and Diabetes, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Michael P Czech
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
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Langkilde A, Andersen O, Henriksen JH, Langberg H, Petersen J, Eugen-Olsen J. Assessment of in situ adipose tissue inflammation by microdialysis. Clin Physiol Funct Imaging 2014; 35:110-9. [PMID: 24494803 DOI: 10.1111/cpf.12134] [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: 09/23/2013] [Accepted: 01/09/2014] [Indexed: 12/21/2022]
Abstract
BACKGROUND Inflammation, and specifically adipose tissue (AT) inflammation, is part of the pathophysiology of obesity and HIV-associated lipodystrophy. Local AT protein assessment methods are limited, and AT inflammation studies have therefore primarily examined inflammatory gene expression. We therefore investigated the utility of microdialysis to study in situ AT interstitial inflammatory protein levels. MATERIAL AND METHODS Abdominal subcutaneous AT microdialysis was performed in six healthy men, six HIV-infected men with lipodystrophy and six without lipodystrophy using the internal references (51) Cr-EDTA and (125) I-human serum albumin. We measured 41 inflammatory proteins in microdialysis samples by Luminex technology, as well as systemic levels in 14 subjects. Furthermore, in vitro studies of the internal reference technique for microdialysis recovery of inflammatory proteins were made. RESULTS We detected in situ AT interstitial levels of 14 inflammatory proteins by microdialysis, while the 27 other inflammatory proteins assessed were only detected sporadically. Initial levels of IL-6 and IL-8 were undetectable. Insertion trauma affected IL-1α, IL-6, IL-8, monocyte chemotactic factor (MCP)-1, IP-10, G-CSF, growth-related oncogene (GRO), macrophage-derived chemokine (MDC) and macrophage inflammatory protein (MIP)-1β levels, while fibroblast growth factor (FGF)-2 was not affected. Systemic and AT interstitial levels were poorly correlated. The microdialysis recovery of smaller proteins was higher than for larger, and the internal references improved microdialysis by accounting for variation in perfusion across the membrane. CONCLUSION Interstitial inflammatory proteins can be sampled in situ using microdialysis. Use of internal references improves the microdialysis technique. However, insertion trauma hampers the use of microdialysis to study AT inflammatory levels, except for FGF-2. Still, microdialysis gives unique insight to in situ AT interstitial concentrations.
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Affiliation(s)
- Anne Langkilde
- Clinical Research Centre, Copenhagen University Hospital, Hvidovre, Denmark
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Gagnon A, Foster C, Landry A, Sorisky A. The role of interleukin 1β in the anti-adipogenic action of macrophages on human preadipocytes. J Endocrinol 2013; 217:197-206. [PMID: 23461871 DOI: 10.1530/joe-12-0565] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
When adipose tissue accumulates in obesity, the ability of preadipocytes to differentiate permits a hyperplastic expansion of functional adipocytes that preserves insulin sensitivity. Adipose infiltration by macrophages is associated with an adipogenic deficit and the appearance of inflamed, insulin-resistant hypertrophied adipocytes. Interleukin 1β (IL1β) has been reported to account for the anti-adipogenic action of macrophages in a mouse model. Using the THP-1 human macrophage cell line and human primary preadipocytes, our objective was to determine whether IL1β was necessary for the ability of conditioned medium from THP-1 macrophages (THP-1-MacCM) to: i) stimulate human preadipocyte inhibitor of κB kinase β (IKKβ) and ii) inhibit human adipocyte differentiation. IL1β is present in THP-1-MacCM, and THP-1-MacCM or IL1β (500 pg/ml; its concentration in THP-1-MacCM) acutely stimulated IKKβ phosphorylation and inhibitor of κB (IκB) degradation in preadipocytes. IL1β was sufficient to inhibit adipogenesis on its own, and this was blocked by SC-514, an IKKβ inhibitor, as has been reported for THP-1-MacCM. IκB degradation by IL1β-immunodepleted THP-1-MacCM was attenuated, whereas IKKβ phosphorylation and the inhibition of adipocyte differentiation were unchanged. Therefore, in contrast to what has been suggested for mouse cell models, IL1β is not required for the ability of MacCM to inhibit adipogenesis in human cell models.
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Affiliation(s)
- Annemarie Gagnon
- Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
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15
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Czech MP, Tencerova M, Pedersen DJ, Aouadi M. Insulin signalling mechanisms for triacylglycerol storage. Diabetologia 2013; 56:949-64. [PMID: 23443243 PMCID: PMC3652374 DOI: 10.1007/s00125-013-2869-1] [Citation(s) in RCA: 176] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 01/22/2013] [Indexed: 02/06/2023]
Abstract
Insulin signalling is uniquely required for storing energy as fat in humans. While de novo synthesis of fatty acids and triacylglycerol occurs mostly in liver, adipose tissue is the primary site for triacylglycerol storage. Insulin signalling mechanisms in adipose tissue that stimulate hydrolysis of circulating triacylglycerol, uptake of the released fatty acids and their conversion to triacylglycerol are poorly understood. New findings include (1) activation of DNA-dependent protein kinase to stimulate upstream stimulatory factor (USF)1/USF2 heterodimers, enhancing the lipogenic transcription factor sterol regulatory element binding protein 1c (SREBP1c); (2) stimulation of fatty acid synthase through AMP kinase modulation; (3) mobilisation of lipid droplet proteins to promote retention of triacylglycerol; and (4) upregulation of a novel carbohydrate response element binding protein β isoform that potently stimulates transcription of lipogenic enzymes. Additionally, insulin signalling through mammalian target of rapamycin to activate transcription and processing of SREBP1c described in liver may apply to adipose tissue. Paradoxically, insulin resistance in obesity and type 2 diabetes is associated with increased triacylglycerol synthesis in liver, while it is decreased in adipose tissue. This and other mysteries about insulin signalling and insulin resistance in adipose tissue make this topic especially fertile for future research.
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Affiliation(s)
- M P Czech
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA.
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Suagee J, Corl B, Crisman M, Pleasant R, Thatcher C, Geor R. Relationships between Body Condition Score and Plasma Inflammatory Cytokines, Insulin, and Lipids in a Mixed Population of Light-Breed Horses. J Vet Intern Med 2012; 27:157-63. [DOI: 10.1111/jvim.12021] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 09/13/2012] [Accepted: 10/23/2012] [Indexed: 11/30/2022] Open
Affiliation(s)
- J.K. Suagee
- Department of Animal and Poultry Sciences; Virginia Polytechnic Institute and State University; Blacksburg VA
| | - B.A. Corl
- Department of Dairy Science; Virginia Polytechnic Institute and State University; Blacksburg VA
| | - M.V. Crisman
- Department of Large Animal Clinical Sciences; Virginia-Maryland Regional College of Veterinary Medicine; Blacksburg VA
| | - R.S. Pleasant
- Department of Large Animal Clinical Sciences; Virginia-Maryland Regional College of Veterinary Medicine; Blacksburg VA
| | - C.D. Thatcher
- Department of Large Animal Clinical Sciences; Virginia-Maryland Regional College of Veterinary Medicine; Blacksburg VA
| | - R.J. Geor
- Department of Animal and Poultry Sciences; Virginia Polytechnic Institute and State University; Blacksburg VA
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Giri H, Muthuramu I, Dhar M, Rathnakumar K, Ram U, Dixit M. Protein tyrosine phosphatase SHP2 mediates chronic insulin-induced endothelial inflammation. Arterioscler Thromb Vasc Biol 2012; 32:1943-50. [PMID: 22628433 DOI: 10.1161/atvbaha.111.239251] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
OBJECTIVE Insulin promotes adhesion of leukocytes to the endothelium through increased expression of surface adhesion molecules. We determined whether src-homology domain-2-containing protein tyrosine phosphatase 2 (SHP2), a downstream effecter of insulin signaling, is involved in insulin-induced endothelial inflammation. METHODS AND RESULTS In human umbilical vein-derived endothelial cells, treatment with insulin (100 nmol/L) increased Tyr(542) phosphorylation, activity, and subsequently expression of SHP2. Increase in SHP2 accompanied a parallel decrease in the availability of the anti-inflammatory molecule, NO. This consequently enhanced the expression of cell adhesion molecules. Decrease in NO index was caused by endothelial NO synthase (eNOS) uncoupling and increased arginase activity. Among the 2 isoforms, insulin treatment induced the expression of arginase II. Inactivation of endogenous SHP2 via NSC87877 [8-hydroxy-7-(6-sulfonapthalen-2-yl)-diazenyl-quinoline-5-sulfonic acid] and its knockdown by small interfering RNA decreased arginase activity by blocking arginase II expression; however, it failed to restore eNOS coupling. Inactivation of SHP2 also abrogated insulin-mediated leukocyte adhesion by blocking the expression of adhesion molecules. Finally, downregulation of endogenous arginase II blocked insulin-mediated endothelial inflammation. CONCLUSIONS SHP2 mediates chronic insulin-induced endothelial inflammation by limiting the production of NO in an eNOS-independent and arginase-II-dependent manner.
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Affiliation(s)
- Hemant Giri
- Department of Biotechnology, Indian Institute of Technology Madras, Chennai-600 036, India
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Suagee JK, Corl BA, Geor RJ. A Potential Role for Pro-Inflammatory Cytokines in the Development of Insulin Resistance in Horses. Animals (Basel) 2012; 2:243-60. [PMID: 26486919 PMCID: PMC4494330 DOI: 10.3390/ani2020243] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 04/16/2012] [Accepted: 04/26/2012] [Indexed: 02/07/2023] Open
Abstract
Insulin resistance is a metabolic condition involving reduced sensitivity of insulin-sensitive tissues to insulin-induced glucose disposal, including adipose tissue, skeletal muscle, and liver. Insulin resistance occurs in overweight and obese horses, and may increase risk for the development of laminitis. The development of insulin resistance is thought to occur in response to increased production of pro-inflammatory cytokines by adipose tissue in obesity, that then have an inhibitory effect on insulin signaling pathways in multiple tissues. This article reviews current knowledge of the involvement of pro-inflammatory cytokines in the development of insulin resistance in horses and uses data from other species to provide context. Understanding the mechanisms involved in the development of insulin resistance in horses should enable development of effective treatment and prevention strategies. Current knowledge of these mechanisms is based upon research in obese humans and rodents, in which there is evidence that the increased production of pro-inflammatory cytokines by adipose tissue negatively influences insulin signaling in insulin-responsive tissues. In horses, plasma concentrations of the cytokine, tumor necrosis factor-α, have been positively correlated with body fatness and insulin resistance, leading to the hypothesis that inflammation may reduce insulin sensitivity in horses. However, little evidence has documented a tissue site of production and a direct link between inflammation and induction of insulin resistance has not been established. Several mechanisms are reviewed in this article, including the potential for macrophage infiltration, hyperinsulinemia, hypoxia, and lipopolysaccharide to increase pro-inflammatory cytokine production by adipose tissue of obese horses. Clearly defining the role of cytokines in reduced insulin sensitivity of horses will be a very important step in determining how obesity and insulin resistance are related.
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Affiliation(s)
- Jessica K Suagee
- Department of Dairy Science, Virginia Tech, Blacksburg, VA 24071, USA.
| | - Benjamin A Corl
- Department of Dairy Science, Virginia Tech, Blacksburg, VA 24071, USA.
| | - Raymond J Geor
- Department of Large Animal Clinical Sciences, Michigan State University, East Lansing, MI 48824, USA.
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Catalano PM, Hauguel-De Mouzon S. Is it time to revisit the Pedersen hypothesis in the face of the obesity epidemic? Am J Obstet Gynecol 2011; 204:479-87. [PMID: 21288502 PMCID: PMC3130827 DOI: 10.1016/j.ajog.2010.11.039] [Citation(s) in RCA: 230] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 11/17/2010] [Accepted: 11/29/2010] [Indexed: 02/06/2023]
Abstract
The Pedersen hypothesis was formulated more than 50 years ago. Jorgen Pedersen primarily cared for women with type 1 diabetes. He suggested that fetal overgrowth was related to increased transplacental transfer of glucose, stimulating the release of insulin by the fetal beta cell and subsequent macrosomia. Optimal maternal glucose control decreased perinatal mortality and morbidity. However, over the ensuing decades, there have been increases in maternal obesity and subsequently gestational diabetes mellitus (GDM) and type 2 diabetes. The underlying pathophysiology of type 1 and GDM/type 2 diabetes are fundamentally different, type 1 diabetes being primarily a disorder of beta cell failure and type 2 diabetes/GDM including both insulin resistance and beta cell dysfunction. As such the metabolic milieu in which the developing fetus is exposed may be quite different in type 1 diabetes and obesity. In this review we examine the metabolic environment of obese diabetic women and lipid metabolism affecting fetal adiposity. The importance of understanding these issues relates to the increasing trends of obesity worldwide with perinatal programming of metabolic dysfunction in the offspring.
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Affiliation(s)
- Patrick M Catalano
- Department of Reproductive Biology, Case Western Reserve University at MetroHealth Medical Center, Cleveland, OH, USA
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Suagee JK, Corl BA, Crisman MV, Hulver MW, McCutcheon LJ, Geor RJ. Effects of acute hyperinsulinemia on inflammatory proteins in horses. Vet Immunol Immunopathol 2011; 142:141-6. [PMID: 21621276 DOI: 10.1016/j.vetimm.2011.05.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 04/05/2011] [Accepted: 05/02/2011] [Indexed: 01/28/2023]
Abstract
Laminitis is a painful, inflammatory disease of the equine hoof that often results in euthanasia. Elevated plasma insulin concentrations are a predictive factor for laminitis, and in previously healthy horses and ponies, laminitis was induced by infusion of insulin. Thus, we chose to determine if an infusion of insulin would increase plasma concentrations of inflammatory cytokines and cytokine mRNA abundance in subcutaneous adipose tissue, skeletal muscle, and white blood cells. Ten mature Thoroughbred mares received an insulin infusion that elevated plasma insulin concentrations for 6h or an equivalent volume of isotonic saline in a switchback design. Insulin infusion altered plasma concentrations of both TNF (P=0.037) and IL-6 (P=0.044), but did not result in consistent changes to either skeletal muscle or adipose tissue cytokine mRNA. Insulin may be involved in the production of inflammatory cytokines, and this could be a mechanism for insulin increasing the risk of laminitis.
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Affiliation(s)
- Jessica K Suagee
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061-0306, USA
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