scholarly journals Immune regulation of islet homeostasis and adaptation

Author(s):  
Jinglong Guo ◽  
Wenxian Fu

Abstract The islet of Langerhans produces endocrine hormones to regulate glucose homeostasis. The normal function of the islet relies on the homeostatic regulations of cellular composition and cell–cell interactions within the islet microenvironment. Immune cells populate the islet during embryonic development and participate in islet organogenesis and function. In obesity, a low-grade inflammation manifests in multiple organs, including pancreatic islets. Obesity-associated islet inflammation is evident in both animal models and humans, characterized by the accumulation of immune cells and elevated production of inflammatory cytokines/chemokines and metabolic mediators. Myeloid lineage cells (monocytes and macrophages) are the dominant types of immune cells in islet inflammation during the development of obesity and type 2 diabetes mellitus (T2DM). In this review, we will discuss the role of the immune system in islet homeostasis and inflammation and summarize recent findings of the cellular and molecular factors that alter islet microenvironment and β cell function in obesity and T2DM.

Diabetes Care ◽  
2015 ◽  
Vol 38 (9) ◽  
pp. 1758-1767 ◽  
Author(s):  
Katharina S. Weber ◽  
Bettina Nowotny ◽  
Klaus Strassburger ◽  
Giovanni Pacini ◽  
Karsten Müssig ◽  
...  

2021 ◽  
Vol 22 (5) ◽  
pp. 2602
Author(s):  
Emilie Viennois ◽  
Benoit Chassaing

Inflammation is a well-characterized critical driver of gastrointestinal cancers. Previous findings have shown that intestinal low-grade inflammation can be promoted by the consumption of select dietary emulsifiers, ubiquitous component of processed foods which alter the composition and function of the gut microbiota. Using a model of colitis-associated cancer, we previously reported that consumption of the dietary emulsifiers carboxymethylcellulose or polysorbate-80 exacerbated colonic tumor development. Here, we investigate the impact of dietary emulsifiers consumption on cancer initiation and progression in a genetical model of intestinal adenomas. In APCmin mice, we observed that dietary emulsifiers consumption enhanced small-intestine tumor development in a way that appeared to be independent of chronic intestinal inflammation but rather associated with emulsifiers’ impact on the proliferative status of the intestinal epithelium as well as on intestinal microbiota composition in both male and female mice. Overall, our findings further support the hypothesis that emulsifier consumption may be a new modifiable risk factor for colorectal cancer (CRC) and that alterations in host–microbiota interactions can favor gastrointestinal carcinogenesis in individuals with a genetical predisposition to such disorders.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Abimbola Adenote ◽  
Igor Dumic ◽  
Cristian Madrid ◽  
Christopher Barusya ◽  
Charles W. Nordstrom ◽  
...  

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.


2018 ◽  
pp. 241-250
Author(s):  
Adaliene Versiani Matos Ferreira ◽  
Laís Bhering Martins ◽  
Nayara Mussi Monteze ◽  
Geneviève Marcelin ◽  
Karine Clément

Eating disorders (EDs) are characterized by dysregulation in eating behavior leading to extreme increase or decrease in food intake that, in turn, changes body weight, adiposity, and physical health. Anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED) are the three major eating disorders. Peculiar immune abnormalities occur in these conditions. Previous studies have reported a higher number of CD4+ T lymphocytes in patients with AN, which are related to a relative resistance to viral infections, even in the presence of leukopenia. It has also been proposed that a cluster of cytokines is altered in these patients. A chronic low-grade inflammation has been observed in obese people with BED and in patients with AN, but with a different profile in each condition. In this context, antagonist drugs of specific cytokines, such as anti-TNF, showed improvement of AN-related symptoms, but increased weight gain in obese subjects. The identification of specific molecules and/or immune cells that impair neuronal circuits implicated in eating behaviors may contribute to the development of pharmacological strategies for eating disorders.


2019 ◽  
Vol 20 (4) ◽  
pp. 839 ◽  
Author(s):  
Erika Di Zazzo ◽  
Rita Polito ◽  
Silvia Bartollino ◽  
Ersilia Nigro ◽  
Carola Porcile ◽  
...  

Adipose tissue is a key regulator of energy balance playing an active role in lipid storage as well as in synthesizing several hormones directly involved in the pathogenesis of obesity. Obesity represents a peculiar risk factor for a growing list of cancers and is frequently associated to poor clinical outcome. The mechanism linking obesity and cancer is not completely understood, but, amongst the major players, there are both chronic low-grade inflammation and deregulation of adipokines secretion. In obesity, the adipose tissue is pervaded by an abnormal number of immune cells that create an inflammatory environment supporting tumor cell proliferation and invasion. Adiponectin (APN), the most abundant adipokine, shows anti-inflammatory, anti-proliferative and pro-apoptotic properties. Circulating levels of APN are drastically decreased in obesity, suggesting that APN may represent the link factor between obesity and cancer risk. The present review describes the recent advances on the involvement of APN and its receptors in the etiology of different types of cancer.


2019 ◽  
Vol 44 (5) ◽  
pp. 512-520 ◽  
Author(s):  
Débora Romualdo Lacerda ◽  
Michele Macedo Moraes ◽  
Albená Nunes-Silva ◽  
Kátia Anunciação Costa ◽  
Débora Fernandes Rodrigues ◽  
...  

Obesity is associated with an energy imbalance that results from excessive energy intake, low diet quality, and a sedentary lifestyle. The increased consumption of a high-refined carbohydrate (HC) diet is strongly related to higher adiposity and low-grade inflammation. Aerobic training is a well-known nonpharmacological intervention to treat obesity and metabolic disturbances. However, the mechanisms through which aerobic training ameliorates the low-grade inflammation induced by an HC diet should be further investigated. Our hypothesis herein was that aerobic training would decrease the recruitment of leukocytes in adipose tissue, thereby reducing the levels of cytokines and improving metabolism in mice fed an HC diet. Male Balb/c mice were assigned to the following groups: control diet/nontrained (C-NT), control diet/trained (C-T), high-refined carbohydrate diet/nontrained (HC-NT), and high-refined carbohydrate diet/trained (HC-T). Mice were submitted to moderate-intensity training sessions that consisted of running 60 min per day for 8 weeks. An intravital microscopy technique was performed in vivo in anesthetized mice to visualize the microvasculature of the adipose tissue. The HC diet induced obesity and increased the influx of immune cells into the adipose tissue. In contrast, HC-T mice presented a lower adiposity and adipocyte area. Furthermore, relative to HC-NT mice, HC-T mice showed increased resting energy expenditure, decreased recruitment of immune cells in the adipose tissue, reduced cytokine levels, and ameliorated hyperglycemia and fatty liver deposition. Collectively, our data enhance understanding about the anti-inflammatory effect of aerobic training and shed light on the adipose tissue-mediated mechanisms by which training promotes a healthier metabolic profile.


2001 ◽  
Vol 281 (5) ◽  
pp. C1422-C1433 ◽  
Author(s):  
Troy Stevens ◽  
Robert Rosenberg ◽  
William Aird ◽  
Thomas Quertermous ◽  
Frances L. Johnson ◽  
...  

Endothelium critically regulates systemic and pulmonary vascular function, playing a central role in hemostasis, inflammation, vasoregulation, angiogenesis, and vascular growth. Indeed, the endothelium integrates signals originating in the circulation with those in the vessel wall to coordinate vascular function. This highly metabolic role differs significantly from the historic view of endothelium, in which it was considered to be merely an inert barrier. New lines of evidence may further change our understanding of endothelium, in regard to both its origin and function. Embryological studies suggest that the endothelium arises from different sites, including angiogenesis of endothelium from macrovascular segments and vasculogenesis of endothelium from microcirculatory segments. These findings suggest an inherent phenotypic distinction between endothelial populations based on their developmental origin. Similarly, diverse environmental cues influence endothelial cell phenotype, critical to not only normal function but also the function of a diseased vessel. Consequently, an improved understanding of site-specific endothelial cell function is essential, particularly with consideration to environmental stimuli present both in the healthy vessel and in development of vasculopathic disease states. The need to examine endothelial cell phenotypes in the context of vascular function served as the basis for a recent workshop sponsored by the National Heart, Lung, and Blood Institute (NHLBI). This report is a synopsis of pertinent topics that were discussed, and future goals and research opportunities identified by the participants of the workshop are presented.


2021 ◽  
Vol 22 (22) ◽  
pp. 12539
Author(s):  
Ludmila Müller ◽  
Svetlana Di Benedetto

Aging is characterized by the dynamic remodeling of the immune system designated “immunosenescence,” and is associated with altered hematopoiesis, thymic involution, and lifelong immune stimulation by multitudinous chronic stressors, including the cytomegalovirus (CMV). Such alterations may contribute to a lowered proportion of naïve T-cells and to reduced diversity of the T-cell repertoire. In the peripheral circulation, a shift occurs towards accumulations of T and B-cell populations with memory phenotypes, and to accumulation of putatively senescent and exhausted immune cells. The aging-related accumulations of functionally exhausted memory T lymphocytes, commonly secreting pro-inflammatory cytokines, together with mediators and factors of the innate immune system, are considered to contribute to the low-grade inflammation (inflammaging) often observed in elderly people. These senescent immune cells not only secrete inflammatory mediators, but are also able to negatively modulate their environments. In this review, we give a short summary of the ways that immunosenescence, inflammaging, and CMV infection may cause insufficient immune responses, contribute to the establishment of the hyperinflammatory syndrome and impact the severity of the coronavirus disease 2019 (COVID-19) in elderly people.


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