ROLE OF ADIPOSE TISSUE AND ADIPOKINES IN CHRONIC INFLAMMATION DEVELOPMENT ON METABOLIC SYNDROME BACKGROUND

2021 ◽  
pp. 83-87
Author(s):  
N. A. Shutova ◽  
I. Yu. Kuzmina

The most pressing issue that combines obesity and insulin resistance is chronic subclinical inflammation, which affects the metabolic and secretory functions of adipose tissue, and is important for the development of pathological processes. The morphological basis of inflammation is the infiltration of adipose tissue by immune competent cells. Biologically active substances specific for adipose tissue are considered to be the collagen−like protein adiponectin and the protein hormone leptin, which are secreted in adipocytes. Leptin stimulates the cellular immune response and increases the production of pro−inflammatory cytokines, and adiponectin is thought to have anti−inflammatory properties. With the development of metabolic syndrome, the concentration of adiponectin in blood decreases, and that of leptin increases. To establish the relationship between serum leptin levels with markers of systemic inflammation and spontaneous production of proinflammatory cytokines as well as mononuclear blood leukocytes, an experimental study was conducted, i.e. modeling the metabolic syndrome in white female rats WAG / GSto aged 5−6 months. The predominance of proinflammatory cytokines: interleukins − 1β, −6, −8, −10, TNF−α in supernatants of mononuclear leukocytes with increasing leptin concentration, which is consistent with the view of its ability to stimulate cell immunity and affect the production of proinflammatory cytokines. It is proven that an increase in leptin levels in metabolic syndrome is not only a symptom that characterizes the functional state of adipose tissue, but also causes spontaneous production of proinflammatory cytokines and mononuclear leukocytes in blood, that is pathogenetically interrelated with the systemic inflammatory response. It is established that the change in the cytokine profile in the serum becomes a forecast of the formation and effectiveness of treatment of metabolic syndrome on the background of obesity. Key words: obesity, metabolic syndrome, undifferentiated chronic inflammation, cytokines.

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Kaivan Khavandi ◽  
Adam Greenstein ◽  
Sarah Withers ◽  
Kazuhiko Sonoyama ◽  
Sarah Lewis ◽  
...  

In order to investigate the contribution of perivascular adipose tissue (PVAT) to arterial function, a total of 55 small arteries harvested from 35 skin biopsies of patients with Metabolic Syndrome and matched controls were mounted as ring preparations in a wire myograph. Contractility to cumulative doses of Norepinephrine in the presence or absence of PVAT showed an anticontractile effect in arteries from healthy volunteers (p=0.009), which was lost in patients with Metabolic Syndrome. Bioassay studies confirmed that PVAT releases a hydrophilic anticontractile factor in health, which is absent in obesity. Using a soluble fragment of the human Type 1 receptor, we identified that the anticontractile factor was adiponectin, which is the sole mediator of vasodilation, acting by increasing endothelial bioavailability of nitric oxide. Significant endothelial dysfunction was observed in patients with Metabolic Syndrome (p<0.001). Quantitative image analysis of adipose tissue revealed significantly increased adipocyte cell size in patients with Metabolic Syndrome, compared with healthy controls (p<0.006). There was immunohistochemical evidence of inflammation with upregulation of TNF-alpha receptor 1 in these patients (p<0.001). Application of exogenous TNF-alpha abolished the anticontractile effect of PVAT by reducing adiponectin bioavailability. Oxidative stress also induced by cytokines TNF-alpha and IL-6 but not IL-1, reduced adiponectin production from PVAT and increased basal tone. When the obese microenvironment was replicated in vitro by inflicting hypoxia on PVAT, adiponectin activity was lost but then rescued by incubation with cytokine antagonists. Further application of the adiponectin receptor fragment abolished PVAT relaxation. We conclude that in healthy arteries, PVAT releases adiponectin which reduces vascular tone. In obesity, this is lost by a cascade of adipocyte hypertrophy, hypoxia, inflammation and oxidative stress. The resulting vasoconstriction contributes to hypertension, hypertriglyceridaemia and insulin resistance. Direct targeting of adiponectin release from PVAT therefore provides a novel therapeutic opportunity in the Metabolic Syndrome.


2018 ◽  
Vol 33 (2) ◽  
pp. 1899-1910 ◽  
Author(s):  
Guanmin Meng ◽  
Xiaoyun Tang ◽  
Zelei Yang ◽  
Yuan Yuan Zhao ◽  
Jonathan M. Curtis ◽  
...  

2017 ◽  
Vol 93 (1) ◽  
pp. 93-103 ◽  
Author(s):  
Yu Meng ◽  
Alfonso Eirin ◽  
Xiang-Yang Zhu ◽  
Hui Tang ◽  
Pritha Chanana ◽  
...  

2018 ◽  
Vol 299 ◽  
pp. 21-31 ◽  
Author(s):  
Leandro Ceotto Freitas-Lima ◽  
Eduardo Merlo ◽  
Marina Campos Zicker ◽  
Juliana Maria Navia-Pelaez ◽  
Miriane de Oliveira ◽  
...  

2018 ◽  
Vol 27 (10) ◽  
pp. 1495-1503 ◽  
Author(s):  
Y. Meng ◽  
A. Eirin ◽  
X.-Y. Zhu ◽  
H. Tang ◽  
L.J. Hickson ◽  
...  

Mesenchymal stem cells (MSCs) constitute an important repair system, but may be impaired by exposure to cardiovascular risk factors. Consequently, adipose tissue-derived MSCs from pigs with the metabolic syndrome (MetS) show decreased vitality. A growing number of microRNAs (miRNAs) are recognized as key modulators of senescence, but their role in regulating senescence in MSC in MetS is unclear. We tested the hypothesis that MetS upregulates in MSC expression of miRNAs that can serve as post-transcriptional regulators of senescence-associated (SA) genes. MSCs were collected from swine abdominal adipose tissue after 16 weeks of Lean or Obese diet ( n = 6 each). Next-generation miRNA sequencing (miRNA-seq) was performed to identify miRNAs up-or down-regulated in MetS-MSCs compared with Lean-MSCs. Functional pathways of SA genes targeted by miRNAs were analyzed using gene ontology. MSC senescence was evaluated by p16 and p21 immunoreactivity, H2AX protein expression, and SA-β-Galactosidase activity. In addition, gene expression of p16, p21, MAPK3 (ERK1) and MAPK14, and MSC migration were studied after inhibition of SA-miR-27b. Senescence biomarkers were significantly elevated in MetS-MSCs. We found seven upregulated miRNAs, including miR-27b, and three downregulated miRNAs in MetS-MSCs, which regulate 35 SA genes, particularly MAPK signaling. Inhibition of miR-27b in cultured MSCs downregulated p16 and MARP3 genes, and increased MSC migration. MetS modulates MSC expression of SA-miRNAs that may regulate their senescence, and the p16 pathway seems to play an important role in MetS-induced MSC senescence.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Masayuki Sugimoto ◽  
Hidenori Arai ◽  
Yukinori Tamura ◽  
Toshinori Murayama ◽  
Koh Ono ◽  
...  

Mulberry leaf (ML) is commonly used to feed silkworms. Previous study showed that ML ameliorates atherosclerosis. However, its mechanism is not completely understood. Because dysregulated production of adipocytokines is involved in the development of the metabolic syndrome and cardiovascular disease, we examined the effect of ML on the production of adipocytokines and metabolic disorders related to the metabolic syndrome, and compared its effect with that of a PPARγ agonist, pioglitazone (Pio). By treating obese diabetic db/db mice with ML, Pio, and their combination, we investigated the mechanism by which they improve metabolic disorders. In this study, db/+m (lean control) and db/db mice were fed a standard diet with or without 3% (w/w) ML and/or 0.01% (w/w) Pio for 12 weeks from 9 weeks of age. At the end of the experiment we found that ML decreased plasma glucose and triglyceride by 32% and 30%, respectively. Interestingly, administration of ML in addition to Pio showed additive effects; further 40% and 30% reduction in glucose and triglyceride compared with Pio treatment, respectively. Moreover, administration of ML in addition to Pio suppressed the body weight increase by Pio treatment and reduced visceral/subcutaneous fat ratio by 20% compared with control db/db mice. Importantly, ML treatment increased expression of adiponectin in white adipose tissue (WAT) by 40%, which was only found in db/db mice, not in control db/+m mice. Combination of ML and Pio increased plasma adiponectin concentrations by 25% and its expression in WAT by 17% compared with Pio alone. In contrast, ML decreased expression of TNF-α and MCP-1 by 25% and 20%, respectively, and the addition of Pio resulted in a further decrease of these cytokines by about 45%. To study the mechanism, we examined the role of oxidative stress. ML decreased the amount of lipid peroxides by 43% and the expression of NADPH oxidase subunits in WAT, which was consistent with the results of TNF-α and MCP-1. Thus our results indicate that ML ameliorates adipocytokine dysregulation by inhibiting oxidative stress in WAT of obese mice, and that ML may have a potential for the treatment of the metabolic syndrome as well as reducing adverse effects of Pio.


Biomolecules ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 97 ◽  
Author(s):  
Esra Demir ◽  
Nazmiye Harmankaya ◽  
İrem Kıraç Utku ◽  
Gönül Açıksarı ◽  
Turgut Uygun ◽  
...  

In this study, it was aimed to investigate the relationship between the epicardial adipose tissue thickness (EATT) and serum IL-17A level insulin resistance in metabolic syndrome patients. This study enrolled a total of 160 subjects, of whom 80 were consecutive patients who applied to our outpatient clinic and were diagnosed with metabolic syndrome, and the other 80 were consecutive patients who were part of the control group with similar age and demographics in whom the metabolic syndrome was excluded. The metabolic syndrome diagnosis was made according to International Diabetes Federation (IDF)-2005 criteria. EATT was measured with transthoracic echocardiography (TTE) in the subjects. IL-17A serum levels were determined using the ELISA method. Fasting blood glucose, HDL, triglyceride, and fasting insulin levels were significantly higher in the metabolic syndrome group compared to the control group. In addition, the metabolic syndrome group had significantly higher high-sensitivity C-reactive protein (hs-CRP) and Homeostatic Model Assessment Insulin Resistance (HOMA-IR) levels than the control group. Similarly, serum IL-17A levels were significantly elevated in the metabolic syndrome group compared to the control group statistically (p < 0.001). As well, EATT was higher in the metabolic syndrome than the control group. Conclusion: By virtue of their proinflammatory properties, EATT and IL-17 may play an important role in the pathogenesis of the metabolic syndrome.


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