The complex role of adipokines in obesity, inflammation, and autoimmunity

Abstract The global obesity epidemic is a major contributor to chronic disease and disability in the world today. Since the discovery of leptin in 1994, a multitude of studies have characterized the pathological changes that occur within adipose tissue in the obese state. One significant change is the dysregulation of adipokine production. Adipokines are an indispensable link between metabolism and optimal immune system function; however, their dysregulation in obesity contributes to chronic low-grade inflammation and disease pathology. Herein, I will highlight current knowledge on adipokine structure and physiological function, and focus on the known roles of these factors in the modulation of the immune response. I will also discuss adipokines in rheumatic and autoimmune diseases.

Download Full-text

Current and Evolving Concepts on the Pathogenesis of Diverticular Disease

Journal of Gastrointestinal and Liver Diseases ◽

10.15403/jgld-184 ◽

2019 ◽

Vol 28 ◽

pp. 225-235 ◽

Cited By ~ 3

Author(s):

Antonio Tursi

Keyword(s):

Diverticular Disease ◽

Current Knowledge ◽

Acute Diverticulitis ◽

Colonic Motility ◽

Human Colon ◽

Recurrent Abdominal Pain ◽

Low Grade ◽

Host Immune Responses ◽

Low Grade Inflammation

Background & Aims: Diverticulosis of the colon is the most common anatomic alteration of the human colon, and it is characterized by the out-pouching of the colonic mucosa and submucosa through the muscular layer. Recurrent abdominal pain is experienced by about 20% of patients with diverticulosis, and inflammation of diverticula may lead to acute diverticulitis. In the past few years, several studies have investigated the factors predisposing or triggering diverticular disease (DD) occurrence. Moreover, new physiopathological knowledge has been acquired. The aim of this study was to review current knowledge regarding the pathogenesis of DD. Methods: A search of PubMed and EMBASE database was performed to identify articles relevant to the pathogenesis of DD. Results: Several papers have shown that genetic predisposition, environmental factors, and colonic dysmotility are implicated in the pathogenesis of DD. More recent studies have associated specific host immune responses, gut microbiota imbalance and therefore low-grade inflammation as contributors to symptom occurrence in DD and diverticulitis. Conclusions: Current and evolving evidence highlighted the role of genetic susceptibility, environment, colonic motility, visceral sensitivity, immune response, and microbiota in the pathogenesis of this disease. Further studies are required to identify potential targets for medical or surgical decision-making.

Download Full-text

The Role of MIF in Type 1 and Type 2 Diabetes Mellitus

Journal of Diabetes Research ◽

10.1155/2014/804519 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6 ◽

Cited By ~ 25

Author(s):

Yuriko I. Sánchez-Zamora ◽

Miriam Rodriguez-Sosa

Keyword(s):

Diabetes Mellitus ◽

Macrophage Migration Inhibitory Factor ◽

Inflammatory Responses ◽

Current Knowledge ◽

Low Grade ◽

Clinical Environment ◽

Low Grade Inflammation

Autoimmunity and chronic low-grade inflammation are hallmarks of diabetes mellitus type one (T1DM) and type two (T2DM), respectively. Both processes are orchestrated by inflammatory cytokines, including the macrophage migration inhibitory factor (MIF). To date, MIF has been implicated in both types of diabetes; therefore, understanding the role of MIF could affect our understanding of the autoimmune or inflammatory responses that influence diabetic pathology. This review highlights our current knowledge about the involvement of MIF in both types of diabetes in the clinical environment and in experimental disease models.

Download Full-text

Mitochondria, immunosenescence and inflammaging: a role for mitokines?

Seminars in Immunopathology ◽

10.1007/s00281-020-00813-0 ◽

2020 ◽

Vol 42 (5) ◽

pp. 607-617 ◽

Cited By ~ 4

Author(s):

Maria Conte ◽

Morena Martucci ◽

Antonio Chiariello ◽

Claudio Franceschi ◽

Stefano Salvioli

Keyword(s):

Immune Responses ◽

Acute Inflammation ◽

Current Knowledge ◽

Low Grade ◽

Mitochondrial Stress ◽

Age Related ◽

Metabolic Mechanism ◽

Anti Inflammatory ◽

Low Grade Inflammation

AbstractA global reshaping of the immune responses occurs with ageing, indicated as immunosenescence, where mitochondria and mitochondrial metabolism play an important role. However, much less is known about the role of mitochondrial stress response in this reshaping and in particular of the molecules induced by such response, collectively indicated as mitokines. In this review, we summarize the current knowledge on the role of mitokines in modulating immune response and inflammation focusing on GDF15, FGF21 and humanin and their possible involvement in the chronic age-related low-grade inflammation dubbed inflammaging. Although many aspects of their biology are still controversial, available data suggest that these mitokines have an anti-inflammatory role and increase with age. Therefore, we hypothesize that they can be considered part of an adaptive and integrated immune-metabolic mechanism activated by mitochondrial dysfunction that acts within the framework of a larger anti-inflammatory network aimed at controlling both acute inflammation and inflammaging.

Download Full-text

The Role of Immunosenescence in Neurodegenerative Diseases

Mediators of Inflammation ◽

10.1155/2018/6039171 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12 ◽

Cited By ~ 28

Author(s):

Erica Costantini ◽

Chiara D’Angelo ◽

Marcella Reale

Keyword(s):

Neurodegenerative Diseases ◽

Physiological Function ◽

Adaptive Immune System ◽

Low Grade ◽

Immune Functions ◽

Thymic Involution ◽

Progressive Decline ◽

Adaptive Immune ◽

Low Grade Inflammation

Aging is characterized by the progressive decline of physiological function and tissue homeostasis leading to increased vulnerability, degeneration, and death. Aging-related changes of the innate and adaptive immune system include decline in the preservation and enhancement of many immune functions, such as changes in the number of circulating monocytic and dendritic cells, thymic involution, T cell polyfunctionality, or production of proinflammatory cytokines, and are defined as immunosenescence. Inflammatory functions are increased with age, causing the chronic low-grade inflammation, referred to as inflamm-aging, that contribute, together with immunosenescence, to neurodegenerative diseases. In this review, we discuss the link between the immune and nervous systems and how the immunosenescence and inflamm-aging can contribute to neurodegenerative diseases.

Download Full-text

The Role of Epicardial Adipose Tissue Lymphocytes in Low-Grade Inflammation and Coronary Artery Disease

Diabetes ◽

10.2337/db18-469-p ◽

2018 ◽

Vol 67 (Supplement 1) ◽

pp. 469-P

Author(s):

MILOS MRAZ ◽

ANNA CINKAJZLOVA ◽

ZDENA LACINOVÁ ◽

JANA KLOUCKOVA ◽

HELENA KRATOCHVILOVA ◽

...

Keyword(s):

Coronary Artery Disease ◽

Adipose Tissue ◽

Coronary Artery ◽

Epicardial Adipose Tissue ◽

Low Grade ◽

Artery Disease ◽

Low Grade Inflammation

Download Full-text

Inflammatory Mediators and Insulin Resistance in Obesity: Role of Nuclear Receptor Signaling in Macrophages

Mediators of Inflammation ◽

10.1155/2010/219583 ◽

2010 ◽

Vol 2010 ◽

pp. 1-10 ◽

Cited By ~ 51

Author(s):

Lucía Fuentes ◽

Tamás Rőszer ◽

Mercedes Ricote

Keyword(s):

Insulin Resistance ◽

Nuclear Receptor ◽

Cytokine Production ◽

Current Knowledge ◽

Liver Steatosis ◽

Visceral Obesity ◽

M2 Macrophage ◽

Low Grade ◽

The Impact

Visceral obesity is coupled to a general low-grade chronic inflammatory state characterized by macrophage activation and inflammatory cytokine production, leading to insulin resistance (IR). The balance between proinflammatory M1 and antiinflammatory M2 macrophage phenotypes within visceral adipose tissue appears to be crucially involved in the development of obesity-associated IR and consequent metabolic abnormalities. The ligand-dependent transcription factors peroxisome proliferator activated receptors (PPARs) have recently been implicated in the determination of the M1/M2 phenotype. Liver X receptors (LXRs), which form another subgroup of the nuclear receptor superfamily, are also important regulators of proinflammatory cytokine production in macrophages. Disregulation of macrophage-mediated inflammation by PPARs and LXRs therefore underlies the development of IR. This review summarizes the role of PPAR and LXR signaling in macrophages and current knowledge about the impact of these actions in the manifestation of IR and obesity comorbidities such as liver steatosis and diabetic osteopenia.

Download Full-text

Adipose tissue inflammation and metabolic dysfunction: a clinical perspective

Hormone Molecular Biology and Clinical Investigation ◽

10.1515/hmbci-2013-0032 ◽

2013 ◽

Vol 15 (1) ◽

Cited By ~ 2

Author(s):

Charmaine S. Tam ◽

Leanne M. Redman

Keyword(s):

Insulin Resistance ◽

Adipose Tissue ◽

Low Grade ◽

Metabolic Dysfunction ◽

Adipose Tissue Inflammation ◽

Tissue Inflammation ◽

Proinflammatory Mediators ◽

Low Grade Inflammation

AbstractObesity is characterized by a state of chronic low-grade inflammation due to increased immune cells, specifically infiltrated macrophages into adipose tissue, which in turn secrete a range of proinflammatory mediators. This nonselective low-grade inflammation of adipose tissue is systemic in nature and can impair insulin signaling pathways, thus, increasing the risk of developing insulin resistance and type 2 diabetes. The aim of this review is to provide an update on clinical studies examining the role of adipose tissue in the development of obesity-associated complications in humans. We will discuss adipose tissue inflammation during different scenarios of energy imbalance and metabolic dysfunction including obesity and overfeeding, weight loss by calorie restriction or bariatric surgery, and conditions of insulin resistance (diabetes, polycystic ovarian syndrome).

Download Full-text

NAFLD and Infection, a Nuanced Relationship

Canadian Journal of Gastroenterology and Hepatology ◽

10.1155/2021/5556354 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Abimbola Adenote ◽

Igor Dumic ◽

Cristian Madrid ◽

Christopher Barusya ◽

Charles W. Nordstrom ◽

...

Keyword(s):

Current Knowledge ◽

Systemic Disease ◽

Type Ii Diabetes Mellitus ◽

Low Grade ◽

Extrahepatic Manifestations ◽

Nonalcoholic Fatty Liver ◽

Multiple Organs ◽

Clostridioides Difficile ◽

Low Grade Inflammation ◽

Ovarian Syndrome

The prevalence of nonalcoholic fatty liver disease (NAFLD) has increased significantly over the last few decades mirroring the increase in obesity and type II diabetes mellitus. NAFLD has become one of the most common indications for liver transplantation. The deleterious effects of NAFLD are not isolated to the liver only, for it has been recognized as a systemic disease affecting multiple organs through protracted low-grade inflammation mediated by the metabolic activity of excessive fat tissue. Extrahepatic manifestations of NAFLD such as cardiovascular disease, polycystic ovarian syndrome, chronic kidney disease, and hypothyroidism have been well described in the literature. In recent years, it has become evident that patients suffering from NAFLD might be at higher risk of developing various infections. The proposed mechanism for this association includes links through hyperglycemia, insulin resistance, alterations in innate immunity, obesity, and vitamin D deficiency. Additionally, a risk independent of these factors mediated by alterations in gut microbiota might contribute to a higher burden of infections in these individuals. In this narrative review, we synthetize current knowledge on several infections including urinary tract infection, pneumonia, Helicobacter pylori, coronavirus disease 2019, and Clostridioides difficile as they relate to NAFLD. Additionally, we explore NAFLD’s association with hidradenitis suppurativa.

Download Full-text

Osteopontin Expression in Human and Murine Obesity: Extensive Local Up-Regulation in Adipose Tissue but Minimal Systemic Alterations

Endocrinology ◽

10.1210/en.2007-1312 ◽

2007 ◽

Vol 149 (3) ◽

pp. 1350-1357 ◽

Cited By ~ 94

Author(s):

Florian W. Kiefer ◽

Maximilian Zeyda ◽

Jelena Todoric ◽

Joakim Huber ◽

René Geyeregger ◽

...

Keyword(s):

Insulin Resistance ◽

Adipose Tissue ◽

Plasma Concentrations ◽

Morbidly Obese ◽

Low Grade ◽

Obese Patients ◽

Multifunctional Protein ◽

Inflammatory Processes ◽

Low Grade Inflammation

Obesity is associated with a chronic low-grade inflammation characterized by macrophage infiltration of adipose tissue (AT) that may underlie the development of insulin resistance and type 2 diabetes. Osteopontin (OPN) is a multifunctional protein involved in various inflammatory processes, cell migration, and tissue remodeling. Because these processes occur in the AT of obese patients, we studied in detail the regulation of OPN expression in human and murine obesity. The study included 20 morbidly obese patients and 20 age- and sex-matched control subjects, as well as two models (diet-induced and genetic) of murine obesity. In high-fat diet-induced and genetically obese mice, OPN expression was drastically up-regulated in AT (40 and 80-fold, respectively) but remained largely unaltered in liver (<2-fold). Moreover, OPN plasma concentrations remained unchanged in both murine models of obesity, suggesting a particular local but not systemic importance for OPN. OPN expression was strongly elevated also in the AT of obese patients compared with lean subjects in both omental and sc AT. In addition, we detected three OPN isoforms to be expressed in human AT and, strikingly, an obesity induced alteration of the OPN isoform expression pattern. Analysis of AT cellular fractions revealed that OPN is exceptionally highly expressed in AT macrophages in humans and mice. Moreover, OPN expression in AT macrophages was strongly up-regulated by obesity. In conclusion, our data point toward a specific local role of OPN in obese AT. Therefore, OPN could be a critical regulator in obesity induced AT inflammation and insulin resistance.

Download Full-text