scholarly journals Adipogenesis: A Necessary but Harmful Strategy

2019 ◽  
Vol 20 (15) ◽  
pp. 3657 ◽  
Author(s):  
Mohammed El Hafidi ◽  
Mabel Buelna-Chontal ◽  
Fausto Sánchez-Muñoz ◽  
Roxana Carbó

Obesity is considered to significantly increase the risk of the development of a vast range of metabolic diseases. However, adipogenesis is a complex physiological process, necessary to sequester lipids effectively to avoid lipotoxicity in other tissues, like the liver, heart, muscle, essential for maintaining metabolic homeostasis and has a crucial role as a component of the innate immune system, far beyond than only being an inert mass of energy storage. In pathophysiological conditions, adipogenesis promotes a pro-inflammatory state, angiogenesis and the release of adipokines, which become dangerous to health. It results in a hypoxic state, causing oxidative stress and the synthesis and release of harmful free fatty acids. In this review, we try to explain the mechanisms occurring at the breaking point, at which adipogenesis leads to an uncontrolled lipotoxicity. This review highlights the types of adipose tissue and their functions, their way of storing lipids until a critical point, which is associated with hypoxia, inflammation, insulin resistance as well as lipodystrophy and adipogenesis modulation by Krüppel-like factors and miRNAs.

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Payal S. Patel ◽  
Eric D. Buras ◽  
Ashok Balasubramanyam

The innate immune system provides organisms with rapid and well-coordinated protection from foreign pathogens. However, under certain conditions of metabolic dysfunction, components of the innate immune system may be activated in the absence of external pathogens, leading to pathologic consequences. Indeed, there appears to be an intimate relationship between metabolic diseases and immune dysfunction; for example, macrophages are prime players in the initiation of a chronic inflammatory state in obesity which leads to insulin resistance. In response to increases in free fatty acid release from obese adipose depots, M1-polarized macrophages infiltrate adipose tissues. These M1 macrophages trigger inflammatory signaling and stress responses within cells that signal through JNK or IKKβpathways, leading to insulin resistance. If overnutrition persists, mechanisms that counteract inflammation (such as M2 macrophages and PPAR signaling) are suppressed, and the inflammation becomes chronic. Although macrophages are a principal constituent of obese adipose tissue inflammation, other components of the immune system such as lymphocytes and mast cells also contribute to the inflammatory cascade. Thus it is not merely an increased mass of adipose tissue that directly leads to attenuation of insulin action, but rather adipose tissue inflammation activated by the immune system in obese individuals that leads to insulin resistance.


Author(s):  
Amanda Almeida de Oliveira ◽  
Kenia Pedrosa Nunes

Abstract A diagnostic of hypertension increases the risk of erectile dysfunction (ED); likewise, ED can be an early sign of hypertension. In both cases, there is evidence that endothelial dysfunction is a common link between the 2 conditions. During hypertension, the sustained and widespread release of procontractile factors (e.g., angiotensin II, endothelin 1, and aldosterone) impairs the balance between vasoconstrictors and vasodilators and, in turn, detrimentally impacts vascular and erectile structures. This prohypertensive state associates with an enhancement in the generation of reactive oxygen species, which is not compensated by internal antioxidant mechanisms. Recently, the innate immune system, mainly via Toll-like receptor 4, has also been shown to actively contribute to the pathophysiology of hypertension and ED not only by inducing oxidative stress but also by sustaining a low-grade inflammatory state. Furthermore, some drugs used to treat hypertension can cause ED and, consequently, reduce compliance with the prescribed pharmacotherapy. To break down these challenges, in this review, we focus on discussing the well-established as well as the emerging mechanisms linking hypertension and ED with an emphasis on the signaling network of the vasculature and corpora cavernosa, the vascular-like structure of the penis.


2020 ◽  
Author(s):  
Carine Teles Sangaleti ◽  
Keyla Yukari Katayama ◽  
Kátia De Angelis ◽  
Tércio Lemos de Moraes ◽  
Amanda Aparecida Araújo ◽  
...  

AbstractBackgroundThe metabolic syndrome (MetS) is an obesity-driven disorder with pandemic proportions and limited treatment options. Oxidative stress, low-grade inflammation and altered autonomic regulation, are important components of MetS pathophysiology. We recently reported that galantamine, an acetylcholinesterase inhibitor and an FDA-approved drug (for Alzheimer’s disease) alleviates the inflammatory state in MetS subjects. Here we examined the effects of galantamine on oxidative stress in parallel with inflammatory and cardio-metabolic parameters in subjects with MetS.MethodsThe effects of galantamine treatment, 8 mg daily for 4 weeks, followed by 16 mg daily for 8 weeks or placebo were studied in randomly assigned subjects with MetS (n=22 per group) of both genders. Oxidative stress, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase activities, lipid and protein peroxidation, and nitrite levels were analyzed before and at the end of the treatment. In addition, plasma cytokine and adipokine levels, insulin resistance (HOMA-IR) and other relevant cardio-metabolic indices were analyzed. Autonomic regulation was also examined by heart rate variability (HRV) before treatment, and at every 4 weeks of treatment.ResultsGalantamine treatment significantly increased antioxidant enzyme activities, including SOD (+1.65 USOD/mg protein, [95% CI 0.39 to 2.92], P=0.004) and CAT (+0.93 nmol/mg, [95% CI 0.34 to 1.51], P=0.011), decreased lipid peroxidation (thiobarbituric acid reactive substances, -5.45 pmol/mg, [95% CI -10.97 to 0.067], P=0.053) and systemic nitrite levels (-0.05 nit/mg protein, [95% CI -0.21 to 0.10], P=0.038) compared with placebo. In addition, galantamine significantly alleviated the inflammatory state and insulin resistance, and decreased the low frequency/high frequency ratio of HRV, following 8 and 12 weeks of drug treatment.ConclusionLow-dose galantamine alleviates oxidative stress, alongside beneficial anti-inflammatory, and metabolic effects, and modulates autonomic regulation in subjects with MetS. These findings are of considerable interest for further studies with galantamine to ameliorate MetS pathophysiology.


Author(s):  
Natália Prearo Moço ◽  
Bruna Ribeiro de Andrade Ramos ◽  
Mariana de Castro Silva ◽  
Jossimara Polettini ◽  
Ramkumar Menon ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Hyun-Ae Seo ◽  
In-Kyu Lee

Metabolic diseases, such as type 2 diabetes and obesity, are increasing globally, and much work has been performed to elucidate the regulatory mechanisms of these diseases. Nuclear factor E2-related factor 2 (Nrf2) is a basic leucine zipper transcription factor that serves as a primary cellular defense against the cytotoxic effects of oxidative stress. Recent studies have proposed a close relationship between oxidative stress and energy metabolism-associated disease. The Nrf2 pathway, as a master regulator of cellular defense against oxidative stress, has emerged as a critical target of energy metabolism; however, its effects are controversial. This review examines the current state of research on the role of Nrf2 on energy metabolism, specifically with respect to its participation in adipocyte differentiation, obesity, and insulin resistance, and discusses the possibility of using Nrf2 as a therapeutic target in the clinic.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Fangming Xiu ◽  
Mile Stanojcic ◽  
Li Diao ◽  
Marc G. Jeschke

Hyperglycemia (HG) and insulin resistance are the hallmarks of a profoundly altered metabolism in critical illness resulting from the release of cortisol, catecholamines, and cytokines, as well as glucagon and growth hormone. Recent studies have proposed a fundamental role of the immune system towards the development of insulin resistance in traumatic patients. A comprehensive review of published literatures on the effects of hyperglycemia and insulin on innate immunity in critical illness was conducted. This review explored the interaction between the innate immune system and trauma-induced hypermetabolism, while providing greater insight into unraveling the relationship between innate immune cells and hyperglycemia. Critical illness substantially disturbs glucose metabolism resulting in a state of hyperglycemia. Alterations in glucose and insulin regulation affect the immune function of cellular components comprising the innate immunity system. Innate immune system dysfunction via hyperglycemia is associated with a higher morbidity and mortality in critical illness. Along with others, we hypothesize that reduction in morbidity and mortality observed in patients receiving insulin treatment is partially due to its effect on the attenuation of the immune response. However, there still remains substantial controversy regarding moderate versus intensive insulin treatment. Future studies need to determine the integrated effects of HG and insulin on the regulation of innate immunity in order to provide more effective insulin treatment regimen for these patients.


Neuroscience ◽  
2017 ◽  
Vol 340 ◽  
pp. 373-383 ◽  
Author(s):  
Shayan Amiri ◽  
Arya Haj-Mirzaian ◽  
Majid Momeny ◽  
Hossein Amini-Khoei ◽  
Maryam Rahimi-Balaei ◽  
...  

Nutrients ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Maria Stefania Spagnuolo ◽  
Susanna Iossa ◽  
Luisa Cigliano

Fructose consumption has drastically increased during the last decades due to the extensive commercial use of high-fructose corn syrup as a sweetener for beverages, snacks and baked goods. Fructose overconsumption is known to induce obesity, dyslipidemia, insulin resistance and inflammation, and its metabolism is considered partially responsible for its role in several metabolic diseases. Indeed, the primary metabolites and by-products of gut and hepatic fructolysis may impair the functions of extrahepatic tissues and organs. However, fructose itself causes an adenosine triphosphate (ATP) depletion that triggers inflammation and oxidative stress. Many studies have dealt with the effects of this sugar on various organs, while the impact of fructose on brain function is, to date, less explored, despite the relevance of this issue. Notably, fructose transporters and fructose metabolizing enzymes are present in brain cells. In addition, it has emerged that fructose consumption, even in the short term, can adversely influence brain health by promoting neuroinflammation, brain mitochondrial dysfunction and oxidative stress, as well as insulin resistance. Fructose influence on synaptic plasticity and cognition, with a major impact on critical regions for learning and memory, was also reported. In this review, we discuss emerging data about fructose effects on brain health in rodent models, with special reference to the regulation of food intake, inflammation, mitochondrial function and oxidative stress, insulin signaling and cognitive function.


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