Inhibition of FOXO1 transcription factor in primary human adipocytes mimics the insulin-resistant state of type 2 diabetes

2018 ◽  
Vol 475 (10) ◽  
pp. 1807-1820 ◽  
Author(s):  
Meenu R. Rajan ◽  
Elin Nyman ◽  
Cecilia Brännmark ◽  
Charlotta S. Olofsson ◽  
Peter Strålfors

Type 2 diabetes is characterized by insulin resistance in the expanding adipose tissue of obesity. The insulin resistance manifests in human adipocytes as system-wide impairment of insulin signalling. An exception is the regulation of transcription factor FOXO1 (forkhead box protein O1), which is phosphorylated downstream of mTORC2 (mammalian/mechanistic target of rapamycin in complex with raptor) and is therefore not exhibiting impaired response to insulin. However, the abundance, and activity, of FOXO1 is reduced by half in adipocytes from patients with diabetes. To elucidate the effect of reduced FOXO1 activity, we here transduced human adipocytes with a dominant-negative construct of FOXO1 (DN-FOXO1). Inhibition of FOXO1 reduced the abundance of insulin receptor, glucose transporter-4, ribosomal protein S6, mTOR and raptor. Functionally, inhibition of FOXO1 induced an insulin-resistant state network-wide, a state that qualitatively and quantitatively mimicked adipocytes from patients with type 2 diabetes. In contrast, and in accordance with these effects of DN-FOXO1, overexpression of wild-type FOXO1 appeared to augment insulin signalling. We combined experimental data with mathematical modelling to show that the impaired insulin signalling in FOXO1-inhibited cells to a large extent can be explained by reduced mTORC1 activity — a mechanism that defines much of the diabetic state in human adipocytes. Our findings demonstrate that FOXO1 is critical for maintaining normal insulin signalling of human adipocytes.

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Elena V Tchetina ◽  
Galina A Markova ◽  
Eugeniya P Sharapova

Osteoarthritis (OA) and type 2 diabetes mellitus (T2D) are two of the most widespread chronic diseases. OA and T2D have common epidemiologic traits, are considered heterogenic multifactorial pathologies that develop through the interaction of genetic and environmental factors, and have common risk factors. In addition, both of these diseases often manifest in a single patient. Despite differences in clinical manifestations, both diseases are characterized by disturbances in cellular metabolism and by an insulin-resistant state primarily associated with the production and utilization of energy. However, currently, the primary cause of OA development and progression is not clear. In addition, although OA is manifested as a joint disease, evidence has accumulated that it affects the whole body. As pathological insulin resistance is viewed as a driving force of T2D development, now, we present evidence that the molecular and cellular metabolic disturbances associated with OA are linked to an insulin-resistant state similar to T2D. Moreover, the alterations in cellular energy requirements associated with insulin resistance could affect many metabolic changes in the body that eventually result in pathology and could serve as a unified mechanism that also functions in many metabolic diseases. However, these issues have not been comprehensively described. Therefore, here, we discuss the basic molecular mechanisms underlying the pathological processes associated with the development of insulin resistance; the major inducers, regulators, and metabolic consequences of insulin resistance; and instruments for controlling insulin resistance as a new approach to therapy.


2003 ◽  
Vol 25 (3) ◽  
pp. 155-167 ◽  
Author(s):  
Shigeru Nakano ◽  
Mitsutaka Kitazawa ◽  
Tomohiko Ito ◽  
Haruhiko Hatakeyama ◽  
Makoto Nishizawa ◽  
...  

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 601.2-602
Author(s):  
J. Avouac ◽  
M. Elhai ◽  
M. Forien ◽  
J. Sellam ◽  
F. Eymard ◽  
...  

Background:Type-2 diabetes and rheumatoid arthritis (RA) are two chronic diseases characterized by tissue inflammation and insulin resistance. To date, no data have evaluated the influence of RA-induced joint and systemic inflammation on the course of type-2 diabetes.Objectives:To study the impact of RA on type-2 diabetesMethods:Observational, multicenter, cross-sectional usual-care study, including 7 rheumatology centers. This study included over a 24-month period consecutive patients with type-2 diabetes and RA, fulfilling the 2010 ACR / EULAR criteria, and diabetic controls with osteoarthritis (OA). The following data were collected: demographics, disease activity and severity indices, current treatment for RA and diabetes, history and complications of diabetes. A systematic blood test was performed, assessing inflammatory (CRP levels) and metabolic (fasting glycemia and insulin levels, HbA1c) parameters. The HOMA2%B (insulin secretion) and HOMA2%S (tissue insulin sensitivity) indices (HOMA calculator, © Diabetes Trials Unit, University of Oxford) were used to assess insulin resistance. Ra and OA patients were compared using parametric tests after adjusting for age and BMI. A multivariate logistic regression was performed ti identify factors independently associated with insulin resistance.Results:We included 122 RA patients (74% women, mean age 64+/-11 years, mean disease duration 15+/-11 11 years, 75% with positive ACPA antibodies and 64% with erosive disease) and 54 controls with OA. 64% of RA patients were treated with oral corticosteroids <10 mg/day, 65% received methotrexate and 53% received targeted biological therapies.The characteristics of type-2 diabetes in the 54 OA patients corresponded to severe insulin-resistant diabetes: age> 65 years, high BMI> 30 kg/m2, mean HbA1c 7.3%+/-11 1.3%, 30% of insulin requirement, high frequency of other cardiovascular risk factors, macroangiopathy found in almost half of patients and biological criteria of insulin resistance (elevation of HOMA2%B and decrease of HOMA2%S).RA patients with type-2 diabetes had a younger age (64+/-11 years vs. 68+/-12 years, p=0.031) and lower BMI (27.7+/-11 5.5 vs. 31.5+/-11 6.3, p<0.001). These patients also had severe diabetes (HbA1c 7.0%+/-11 1.2%, 29% of insulin requirement, 43% of macroangiopathy) with an insulin resistance profile identical to OA controls. After adjusting for age and BMI, RA patients had a significantly increased insulin secretion compared to OA patients (HOMA2%B: 83.1+/-11 65.2 vs. 49.3+/-11 25.7, p=0.023) as well as a significant reduction of insulin sensitivity (HOMA2%S: 61.1+/-11 31.6 vs. 92.9+/-11 68.1, p=0.016). This insulin resistance was associated with the inflammatory activity of RA, with a negative correlation between the HOMA2%S and the DAS28 (r=-0.28, p=0.027). The multivariate logistic regression confirmed the independent association between the HOMA2%S index and DAS28 (OR: 3.93, 95% CI 1.02-15.06), as well as high blood pressure (OR: 1.29, 95% CI 0.33-1.99 CI).Conclusion:RA patients with type-2 diabetes displayed severe, poorly controlled diabetes, highlighting the burden of comorbidities associated with RA. The clinical-biological profile of diabetic RA patients was severe insulin-resistant diabetes, with a biological profile of insulin resistance linked to the inflammatory activity of the disease. These findings may have therapeutic implications, with the potential targeting of insulin resistance through the treatment of joint and systemic inflammation.Acknowledgments:Société Française de Rhumatologie (research grant)Bristol Myers Squibb (research grant)Disclosure of Interests:Jérôme Avouac Grant/research support from: Pfizer, Bristol Myers Squibb, Consultant of: Sanofi, Bristol Myers Squibb, Abbvie, Boerhinger, Nordic Pharma, Speakers bureau: Sanofi, Bristol Myers Squibb Abbvie, MSD, Pfizer, Nordic Pharma, Muriel ELHAI: None declared, Marine Forien: None declared, Jérémie SELLAM: None declared, Florent Eymard Consultant of: Regenlab, Anna Moltó Grant/research support from: Pfizer, UCB, Consultant of: Abbvie, BMS, MSD, Novartis, Pfizer, UCB, Laure Gossec Grant/research support from: Lilly, Mylan, Pfizer, Sandoz, Consultant of: AbbVie, Amgen, Biogen, Celgene, Janssen, Lilly, Novartis, Pfizer, Sandoz, Sanofi-Aventis, UCB, Frédéric Banal: None declared, Joel Daminano: None declared, Philippe Dieudé: None declared, Yannick Allanore Shareholder of: Sanofi, Roche, Consultant of: Actelion, Bayer, BMS, Boehringer Ingelheim, Inventiva, Sanofi


2004 ◽  
Vol 36 (8) ◽  
pp. 531-537 ◽  
Author(s):  
P. Algenstaedt ◽  
N. Rosenblatt ◽  
I. Kolb ◽  
A. Krützelmann ◽  
B. Schwarzloh ◽  
...  

2021 ◽  
pp. 1-9

1. Abstract Insulin Resistance is the leading cause of Type 2 diabetes mellitus [T2DM] onset. It occurs as a result of disturbances in lipid metabolism and increased levels of circulating free fatty acids [FFAs]. FFAs accumulate within the insulin sensitive tissues such as muscle, liver and adipose tissues exacerbating different molecular mechanisms. Increased fatty acid flux has been documented to be strongly associated with insulin resistant states and obesity causing inflammation that eventually causes type 2-diabetes development. FFAs appear to cause this defect in glucose transport by inhibiting insulin –stimulated tyrosine phosphorylation of insulin receptor substrate-1 [IRS-1] and IRS-1 associated phosphatidyl-inositol 3-kinase activity. A number of different metabolic abnormalities may increase intramyocellular or intrahepatic fatty acid metabolites that induce insulin resistance through different cellular mechanisms. The current review point out the link between enhanced FFAs flux and activation of PKC and how it impacts on both the insulin signaling in muscle and liver as shown from our laboratory data and highlighting the involvement of the inflammatory pathways importance. This embarks the importance of measuring the inflammatory biomarkers in clinical settings.


2021 ◽  
pp. 1-13

1. Abstract Insulin Resistance is the leading cause of Type 2 diabetes mellitus (T2D). It occurs as a result of lipid disorders and increased levels of circulating free fatty acids (FFAs). FFAs accumulate within the insulin sensitive tissues such as muscle, liver and adipose tissues exacerbating different molecular mechanisms. Increased levels fatty acid has been documented to be strongly associated with insulin resistant states and obesity causing inflammation that eventually causes type 2-diabetes. Among the biomarkers that are accompanying low grade inflammation include IL-1β, IL-6 and TNF-α. The current review point out the importance of measuring the inflammatory biomarkers especially focusing on the conductance and measurement for IL-6 as a screening laboratory test and its diagnostic value in clinical practice.


Author(s):  
Yoshiro Saito

Abstract Selenoprotein P (SeP; encoded by SELENOP) is selenium (Se)-rich plasma protein that is mainly produced in the liver. SeP functions as a Se-transport protein to deliver Se from the liver to other tissues, such as the brain and testis. The protein plays a pivotal role in Se metabolism and antioxidative defense, and it has been identified as a ‘hepatokine’ that causes insulin resistance in type 2 diabetes. SeP levels are increased in type 2 diabetes patients, and excess SeP impairs insulin signalling, promoting insulin resistance. Furthermore, increased levels of SeP disturb the functioning of pancreatic β cells and inhibit insulin secretion. This review focuses on the biological function of SeP and the molecular mechanisms associated with the adverse effects of excess SeP on pancreatic β cells’ function, particularly with respect to redox reactions. Interactions between the liver and pancreas are also discussed.


2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Haya Al-Sulaiti ◽  
Ilhame Diboun ◽  
Maha V. Agha ◽  
Fatima F. S. Mohamed ◽  
Stephen Atkin ◽  
...  

Abstract Background Obesity is associated with an increased risk of insulin resistance and type 2 diabetes mellitus (T2DM). However, some obese individuals maintain their insulin sensitivity and exhibit a lower risk of associated comorbidities. The underlying metabolic pathways differentiating obese insulin sensitive (OIS) and obese insulin resistant (OIR) individuals remain unclear. Methods In this study, 107 subjects underwent untargeted metabolomics of serum samples using the Metabolon platform. Thirty-two subjects were lean controls whilst 75 subjects were obese including 20 OIS, 41 OIR, and 14 T2DM individuals. Results Our results showed that phospholipid metabolites including choline, glycerophosphoethanolamine and glycerophosphorylcholine were significantly altered from OIS when compared with OIR and T2DM individuals. Furthermore, our data confirmed changes in metabolic markers of liver disease, vascular disease and T2DM, such as 3-hydroxymyristate, dimethylarginine and 1,5-anhydroglucitol, respectively. Conclusion This pilot data has identified phospholipid metabolites as potential novel biomarkers of obesity-associated insulin sensitivity and confirmed the association of known metabolites with increased risk of obesity-associated insulin resistance, with possible diagnostic and therapeutic applications. Further studies are warranted to confirm these associations in prospective cohorts and to investigate their functionality.


2019 ◽  
Vol 476 (16) ◽  
pp. 2371-2391 ◽  
Author(s):  
Saynaz A. Choudhary ◽  
Nikita Bora ◽  
Dipanjan Banerjee ◽  
Leena Arora ◽  
Anindhya Sundar Das ◽  
...  

Abstract Saturated free fatty acid-induced adipocyte inflammation plays a pivotal role in implementing insulin resistance and type 2 diabetes. Recent reports suggest A2A adenosine receptor (A2AAR) could be an attractive choice to counteract adipocyte inflammation and insulin resistance. Thus, an effective A2AAR agonist devoid of any toxicity is highly appealing. Here, we report that indirubin-3′-monoxime (I3M), a derivative of the bisindole alkaloid indirubin, efficiently binds and activates A2AAR which leads to the attenuation of lipid-induced adipocyte inflammation and insulin resistance. Using a combination of in silico virtual screening of potential anti-diabetic candidates and in vitro study on insulin-resistant model of 3T3-L1 adipocytes, we determined I3M through A2AAR activation markedly prevents lipid-induced impairment of the insulin signaling pathway in adipocytes without any toxic effects. While I3M restrains lipid-induced adipocyte inflammation by inhibiting NF-κB dependent pro-inflammatory cytokines expression, it also augments cAMP-mediated CREB activation and anti-inflammatory state in adipocytes. However, these attributes were compromised when cells were pretreated with the A2AAR antagonist, SCH 58261 or siRNA mediated knockdown of A2AAR. I3M, therefore, could be a valuable option to intervene adipocyte inflammation and thus showing promise for the management of insulin resistance and type 2 diabetes.


2011 ◽  
Vol 43 (3) ◽  
pp. 110-120 ◽  
Author(s):  
Nicky Konstantopoulos ◽  
Victoria C. Foletta ◽  
David H. Segal ◽  
Katherine A. Shields ◽  
Andrew Sanigorski ◽  
...  

Insulin resistance is a heterogeneous disorder caused by a range of genetic and environmental factors, and we hypothesize that its etiology varies considerably between individuals. This heterogeneity provides significant challenges to the development of effective therapeutic regimes for long-term management of type 2 diabetes. We describe a novel strategy, using large-scale gene expression profiling, to develop a gene expression signature (GES) that reflects the overall state of insulin resistance in cells and patients. The GES was developed from 3T3-L1 adipocytes that were made “insulin resistant” by treatment with tumor necrosis factor-α (TNF-α) and then reversed with aspirin and troglitazone (“resensitized”). The GES consisted of five genes whose expression levels best discriminated between the insulin-resistant and insulin-resensitized states. We then used this GES to screen a compound library for agents that affected the GES genes in 3T3-L1 adipocytes in a way that most closely resembled the changes seen when insulin resistance was successfully reversed with aspirin and troglitazone. This screen identified both known and new insulin-sensitizing compounds including nonsteroidal anti-inflammatory agents, β-adrenergic antagonists, β-lactams, and sodium channel blockers. We tested the biological relevance of this GES in participants in the San Antonio Family Heart Study ( n = 1,240) and showed that patients with the lowest GES scores were more insulin resistant (according to HOMA_IR and fasting plasma insulin levels; P < 0.001). These findings show that GES technology can be used for both the discovery of insulin-sensitizing compounds and the characterization of patients into subtypes of insulin resistance according to GES scores, opening the possibility of developing a personalized medicine approach to type 2 diabetes.


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