scholarly journals Linking atypical depression and insulin resistance-related disorders via low-grade chronic inflammation: integrating the phenotypic, molecular and neuroanatomical dimensions

Author(s):  
Zümrüt Duygu Sen ◽  
Lena Vera Danyeli ◽  
Marie Woelfer ◽  
Femke Lamers ◽  
Gerd Wagner ◽  
...  
2019 ◽  
Vol 7 (1) ◽  
pp. e000783 ◽  
Author(s):  
Liang Xu ◽  
Naoto Nagata ◽  
Guanliang Chen ◽  
Mayumi Nagashimada ◽  
Fen Zhuge ◽  
...  

ObjectiveWe reported previously that empagliflozin—a sodium-glucose cotransporter (SGLT) 2 inhibitor—exhibited preventive effects against obesity. However, it was difficult to extrapolate these results to human subjects. Here, we performed a therapeutic study, which is more relevant to clinical situations in humans, to investigate antiobesity effects of empagliflozin and illustrate the mechanism underlying empagliflozin-mediated enhanced fat browning in obese mice.Research design and methodsAfter 8 weeks on a high-fat diet (HFD), C57BL/6J mice exhibited obesity, accompanied by insulin resistance and low-grade chronic inflammation. Cohorts of obese mice were continued on the HFD for an additional 8-week treatment period with or without empagliflozin.ResultsTreatment with empagliflozin for 8 weeks markedly increased glucose excretion in urine, and suppressed HFD-induced weight gain, insulin resistance and hepatic steatosis. Notably, empagliflozin enhanced oxygen consumption and carbon dioxide production, leading to increased energy expenditure. Consistently, the level of uncoupling protein 1 expression was increased in both brown and white (WAT) adipose tissues of empagliflozin-treated mice. Furthermore, empagliflozin decreased plasma levels of interleukin (IL)-6 and monocyte chemoattractant protein-1, but increased plasma levels of IL-33 and adiponectin in obese mice. Finally, we found that empagliflozin reduced M1-polarized macrophage accumulation, while inducing the anti-inflammatory M2 phenotype of macrophages in the WAT and liver, thereby attenuating obesity-related chronic inflammation.ConclusionsTreatment with empagliflozin attenuated weight gain by increasing energy expenditure and adipose tissue browning, and alleviated obesity-associated inflammation and insulin resistance by alternative macrophage activation in the WAT and liver of obese mice.


2020 ◽  
Vol 27 ◽  
Author(s):  
Amin Gasmi ◽  
Sadaf Noor ◽  
Alain Menzel ◽  
Alexandru Doşa ◽  
Lyudmila Pivina ◽  
...  

Background: Obesity is known to be a multifactorial disease. In its pathogenesis, different factors such as chronic inflammation, oxidative stress, insulin resistance, genetic factors, environmental effects, vegetative disturbance, and unbalanced nutrition play a significant role. Methodology: This study describes the association of obesity and insulin resistance with chronic inflammation, genetic, and epigenetic factors. Previous literature has been reviewed to explain the relation of obesity with those factors involved in chronic low-grade inflammation and insulin. Results: Obesity is associated with a decrease in ghrelin secretion, elevated plasma leptin levels, oxidative stress, increased macrophage phagocytic activity, and the induction of pro-inflammatory synthesis of cytokines and interferon-gamma. Obesity is linked to decreased levels of cytochrome P450 (CYP) enzymes and impaired detoxification processes. Deficiency of vitamins and minerals can also play a significant role in the development of oxidative stress and chronic inflammation in obesity. There is evidence of associations between a genetic predisposition to obesity in children with elevated levels of certain miRNAs. Conclusion: The purpose of the present review is an analysis of the multiple factors associated with obesity.


2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
José Romeo Villarreal-Calderón ◽  
Ricardo X. Cuéllar ◽  
Martín R. Ramos-González ◽  
Nestor Rubio-Infante ◽  
Elena C. Castillo ◽  
...  

Low-grade chronic inflammation plays a pivotal role among other pathophysiological mechanisms involved in obesity. Innate and adaptive immune cells undergo systemic proinflammatory polarization that gives rise to an increased secretion of proinflammatory cytokines, which in turn leads to insulin resistance. Bariatric surgery is currently the most effective treatment for obesity, as it brings on significant weight loss, glucose metabolism improvement, and a decrease in systemic inflammation biomarkers. After bariatric surgery, several changes have been reported to occur in adaptive immunity, including reduction in CD4+ and CD8+ T cell counts, a decrease in the Th1/Th2 ratio, an increase in B regulatory cells, and reduction in proinflammatory cytokine secretion. Overall, there seems to be a major shift in several lymphocyte populations from a proinflammatory to an anti-inflammatory phenotype. Furthermore, increased antioxidant activity and reduced lipid and DNA oxidation products have been reported after bariatric surgery in circulating mononuclear cells. This paper highlights the shift in the adaptive immune system in response to weight loss and improved insulin sensitivity, as well as the interplay between immunological and metabolic adaptations as a result of bariatric surgery. Finally, based on data from research, we propose several mechanisms such as changes in adaptive immune cell phenotypes and their by-products, recruitment in adipose tissue, reduced oxidative stress, and modification in metabolic substrate availability as drivers to reduce low-grade chronic inflammation after bariatric surgery in severe obesity.


2020 ◽  
Vol 2020 ◽  
pp. 1-5 ◽  
Author(s):  
Hana Alzamil

Background. Diabetes and obesity are very common associated metabolic disorders that are linked to chronic inflammation. Leptin is one of the important adipokines released from adipocytes, and its level increases with increasing body mass index (BMI). Tumor necrosis factor alpha (TNF-α) is a cytokine that is released by adipocytes and inflammatory cells in response to chronic inflammation. Type 2 diabetes mellitus (T2DM) is believed to be associated with low-grade chronic inflammation. The current study aims to investigate the involvement of leptin and TNF-α in T2DM associated with obesity. Methodology. This is a cross-sectional study involving 63 healthy volunteers and 65 patients with T2DM. Body composition was measured, and fasting venous blood samples were analyzed for blood glucose, glycosylated hemoglobin (HbA1c), basal insulin, leptin, and TNF-α. HbA1c was measured by the affinity column method. Insulin, leptin, and TNF-α immunoassays were performed by the ELISA technique. Insulin resistance and beta-cell function were assessed using the homeostasis model assessment (HOMA-IR and HOMA-B). Results. Our study showed a significantly higher level of TNF-α in T2DM patients compared to controls (7.51 ± 2.48 and 6.19 ± 3.01, respectively; p=0.008). In obese diabetic patients, the serum level of TNF-α was significantly higher in comparison with nonobese diabetic patients (p<0.018) and obese nondiabetic group (p<0.001). TNF-α correlated positively with HbA1c (r = 0.361, p=0.003) and HOMA-IR (r = 0.296, p=0.017) in patients with T2DM. Conclusion. TNF-α is associated with concurrent obesity and T2DM and correlates with HbA1c. This suggests that TNF-α needs further investigation to explore if it has a role in monitoring the effectiveness of management in individuals with obesity and T2DM.


2021 ◽  
Vol 22 (11) ◽  
pp. 5603
Author(s):  
Anna Litwiniuk ◽  
Wojciech Bik ◽  
Małgorzata Kalisz ◽  
Agnieszka Baranowska-Bik

Alzheimer’s disease (AD) is the most common form of neurodegenerative dementia. Metabolic disorders including obesity and type 2 diabetes mellitus (T2DM) may stimulate amyloid β (Aβ) aggregate formation. AD, obesity, and T2DM share similar features such as chronic inflammation, increased oxidative stress, insulin resistance, and impaired energy metabolism. Adiposity is associated with the pro-inflammatory phenotype. Adiposity-related inflammatory factors lead to the formation of inflammasome complexes, which are responsible for the activation, maturation, and release of the pro-inflammatory cytokines including interleukin-1β (IL-1β) and interleukin-18 (IL-18). Activation of the inflammasome complex, particularly NLRP3, has a crucial role in obesity-induced inflammation, insulin resistance, and T2DM. The abnormal activation of the NLRP3 signaling pathway influences neuroinflammatory processes. NLRP3/IL-1β signaling could underlie the association between adiposity and cognitive impairment in humans. The review includes a broadened approach to the role of obesity-related diseases (obesity, low-grade chronic inflammation, type 2 diabetes, insulin resistance, and enhanced NLRP3 activity) in AD. Moreover, we also discuss the mechanisms by which the NLRP3 activation potentially links inflammation, peripheral and central insulin resistance, and metabolic changes with AD.


2021 ◽  
Vol 22 (19) ◽  
pp. 10212
Author(s):  
Luan Américo-Da-Silva ◽  
Javiera Aguilera ◽  
Oscar Quinteros-Waltemath ◽  
Pablo Sánchez-Aguilera ◽  
Javier Russell ◽  
...  

Low-grade chronic inflammation plays a pivotal role in the pathogenesis of insulin resistance (IR), and skeletal muscle has a central role in this condition. NLRP3 inflammasome activation pathways promote low-grade chronic inflammation in several tissues. However, a direct link between IR and NLRP3 inflammasome activation in skeletal muscle has not been reported. Here, we evaluated the NLRP3 inflammasome components and their role in GLUT4 translocation impairment in skeletal muscle during IR. Male C57BL/6J mice were fed with a normal control diet (NCD) or high-fat diet (HFD) for 8 weeks. The protein levels of NLRP3, ASC, caspase-1, gasdermin-D (GSDMD), and interleukin (IL)-1β were measured in both homogenized and isolated fibers from the flexor digitorum brevis (FDB) or soleus muscle. GLUT4 translocation was determined through GLUT4myc-eGFP electroporation of the FBD muscle. Our results, obtained using immunofluorescence, showed that adult skeletal muscle expresses the inflammasome components. In the FDB and soleus muscles, homogenates from HFD-fed mice, we found increased protein levels of NLRP3 and ASC, higher activation of caspase-1, and elevated IL-1β in its mature form, compared to NCD-fed mice. Moreover, GSDMD, a protein that mediates IL-1β secretion, was found to be increased in HFD-fed-mice muscles. Interestingly, MCC950, a specific pharmacological NLRP3 inflammasome inhibitor, promoted GLUT4 translocation in fibers isolated from the FDB muscle of NCD- and HFD-fed mice. In conclusion, we found increased NLRP3 inflammasome components in adult skeletal muscle of obese insulin-resistant animals, which might contribute to the low-grade chronic metabolic inflammation of skeletal muscle and IR development.


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