scholarly journals Cell biology of fat storage

2016 ◽  
Vol 27 (16) ◽  
pp. 2523-2527 ◽  
Author(s):  
Paul Cohen ◽  
Bruce M. Spiegelman
Keyword(s):  
Immune Cells ◽  
Cell Biology ◽  
Critical Role ◽  
Cell Types ◽  
Fat Cells ◽  
Obesity And Diabetes ◽  
Beige Adipocytes ◽  
Therapeutic Development ◽  
White Fat

The worldwide epidemic of obesity and type 2 diabetes has greatly increased interest in the biology and physiology of adipose tissues. Adipose (fat) cells are specialized for the storage of energy in the form of triglycerides, but research in the last few decades has shown that fat cells also play a critical role in sensing and responding to changes in systemic energy balance. White fat cells secrete important hormone-like molecules such as leptin, adiponectin, and adipsin to influence processes such as food intake, insulin sensitivity, and insulin secretion. Brown fat, on the other hand, dissipates chemical energy in the form of heat, thereby defending against hypothermia, obesity, and diabetes. It is now appreciated that there are two distinct types of thermogenic fat cells, termed brown and beige adipocytes. In addition to these distinct properties of fat cells, adipocytes exist within adipose tissue, where they are in dynamic communication with immune cells and closely influenced by innervation and blood supply. This review is intended to serve as an introduction to adipose cell biology and to familiarize the reader with how these cell types play a role in metabolic disease and, perhaps, as targets for therapeutic development.

scholarly journals Emerging concepts and future challenges in innate lymphoid cell biology

2016 ◽  
Vol 213 (11) ◽  
pp. 2229-2248 ◽  
Author(s):  
Elia D. Tait Wojno ◽  
David Artis
Keyword(s):  
Immune Cells ◽  
Cell Biology ◽  
Critical Role ◽  
Cell Types ◽  
Lymphoid Cells ◽  
Adaptive Immune Cells ◽  
New Findings ◽  
Basic Studies ◽  
New Treatments ◽  
And Function

Innate lymphoid cells (ILCs) are innate immune cells that are ubiquitously distributed in lymphoid and nonlymphoid tissues and enriched at mucosal and barrier surfaces. Three major ILC subsets are recognized in mice and humans. Each of these subsets interacts with innate and adaptive immune cells and integrates cues from the epithelium, the microbiota, and pathogens to regulate inflammation, immunity, tissue repair, and metabolic homeostasis. Although intense study has elucidated many aspects of ILC development, phenotype, and function, numerous challenges remain in the field of ILC biology. In particular, recent work has highlighted key new questions regarding how these cells communicate with their environment and other cell types during health and disease. This review summarizes new findings in this rapidly developing field that showcase the critical role ILCs play in directing immune responses through their ability to interact with a variety of hematopoietic and nonhematopoietic cells. In addition, we define remaining challenges and emerging questions facing the field. Finally, this review discusses the potential application of basic studies of ILC biology to the development of new treatments for human patients with inflammatory and infectious diseases in which ILCs play a role.

scholarly journals The Beige Adipocyte as a Therapy for Metabolic Diseases

2019 ◽  
Vol 20 (20) ◽  
pp. 5058 ◽  
Author(s):  
Fernando Lizcano
Keyword(s):  
Diabetes Mellitus ◽  
Adipose Tissue ◽  
Diabetes Mellitus Type 2 ◽  
Metabolic Diseases ◽  
Brown Fat ◽  
Diabetes Mellitus Type ◽  
Beige Adipocyte ◽  
Obesity And Diabetes ◽  
Beige Adipocytes

Adipose tissue is traditionally categorized into white and brown relating to their function and morphology. The classical white adipose tissue builds up energy in the form of triglycerides and is useful for preventing fatigue during periods of low caloric intake and the brown adipose tissue more energetically active, with a greater number of mitochondria and energy production in the form of heat. Since adult humans possess significant amounts of active brown fat depots and its mass inversely correlates with adiposity, brown fat might play an important role in human obesity and energy homeostasis. New evidence suggests two types of thermogenic adipocytes with distinct developmental and anatomical features: classical brown adipocytes and beige adipocytes. Beige adipocyte has recently attracted special interest because of its ability to dissipate energy and the possible ability to differentiate themselves from white adipocytes. The presence of brown and beige adipocyte in human adults has acquired attention as a possible therapeutic intervention for metabolic diseases. Importantly, adult human brown appears to be mainly composed of beige-like adipocytes, making this cell type an attractive therapeutic target for obesity and obesity-related diseases, such as atherosclerosis, arterial hypertension and diabetes mellitus type 2. Because many epigenetics changes can affect beige adipocyte differentiation from adipose progenitor cells, the knowledge of the circumstances that affect the development of beige adipocyte cells may be important to new pathways in the treatment of metabolic diseases. New molecules have emerged as possible therapeutic targets, which through the impulse to develop beige adipocytes can be useful for clinical studies. In this review will discuss some recent observations arising from the unique physiological capacity of these cells and their possible role as ways to treat obesity and diabetes mellitus type 2.

scholarly journals The cell biology of inflammation: From common traits to remarkable immunological adaptations

2020 ◽  
Vol 219 (7) ◽  
Author(s):  
Helen Weavers ◽  
Paul Martin
Keyword(s):  
Innate Immunity ◽  
Cell Division ◽  
Membrane Trafficking ◽  
Immune Cells ◽  
Cell Biology ◽  
Foreign Bodies ◽  
Cell Types ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Starting Point

Tissue damage triggers a rapid and robust inflammatory response in order to clear and repair a wound. Remarkably, many of the cell biology features that underlie the ability of leukocytes to home in to sites of injury and to fight infection—most of which are topics of intensive current research—were originally observed in various weird and wonderful translucent organisms over a century ago by Elie Metchnikoff, the “father of innate immunity,” who is credited with discovering phagocytes in 1882. In this review, we use Metchnikoff’s seminal lectures as a starting point to discuss the tremendous variety of cell biology features that underpin the function of these multitasking immune cells. Some of these are shared by other cell types (including aspects of motility, membrane trafficking, cell division, and death), but others are more unique features of innate immune cells, enabling them to fulfill their specialized functions, such as encapsulation of invading pathogens, cell–cell fusion in response to foreign bodies, and their self-sacrifice as occurs during NETosis.

The role of SLAM family receptors in immune cell signalingThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease.

2006 ◽  
Vol 84 (6) ◽  
pp. 832-843 ◽  
Author(s):  
Elena A. Ostrakhovitch ◽  
Shawn S.-C. Li
Keyword(s):  
Immune Cells ◽  
Immune Cell ◽  
Current Knowledge ◽  
Critical Role ◽  
Cell Types ◽  
Health And Disease ◽  
Slam Family ◽  
Different Cell Types ◽  
Selection Of

The signaling lymphocyte-activating molecule (SLAM) family immunoreceptors are expressed in a wide array of immune cells, including both T and B lymphocytes. By virtue of their ability to transduce tyrosine phosphorylation signals through the so-called ITSM (immunoreceptor tyrosine-based switch motif) sequences, they play an important part in regulating both innate and adaptive immune responses. The critical role of the SLAM immunoreceptors in mediating normal immune reactions was highlighted in recent findings that SAP, a SLAM-associated protein, modulates the activities of various immune cells through interactions with different members of the SLAM family expressed in these cells. Importantly, mutations or deletions of the sap gene in humans result in the X-linked lymphoproliferative syndrome. In this review, we summarize current knowledge and survey the latest developments in signal transduction events triggered by the activation of SLAM family receptors in different cell types.

scholarly journals miR17-92 cluster drives white adipose tissue browning

2020 ◽  
Vol 65 (3) ◽  
pp. 97-107
Author(s):  
Yuanyuan Huang ◽  
Hanlin Zhang ◽  
Meng Dong ◽  
Lei Zhang ◽  
Jun Lin ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Critical Role ◽  
Beneficial Effects ◽  
Brown Adipose ◽  
Beige Adipocytes ◽  
Beige Fat ◽  
And Function ◽  
White Fat

White adipose tissue (WAT) browning may have beneficial effects for treating metabolic syndrome. miRNA are important regulators of the differentiation, development, and function of brown and beige adipocytes. Here, we found that the cold-inducible miRNA17-92 cluster is enriched in brown adipose tissue (BAT) compared with WAT. Overexpression of the miR17-92 cluster in C3H10T1/2 cells, a mouse mesenchymal stem cell line, enhanced the thermogenic capacity of adipocytes. Furthermore, we observed a significant reduction in adiposity in adipose tissue-specific miR17-92 cluster transgenic (TG) mice. This finding is partly explained by dramatic increases in white fat browning and energy expenditure. Interestingly, the miR17-92 cluster stimulated WAT browning without altering BAT activity in mice. In addition, when we removed the intrascapular BAT (iBAT), the TG mice could maintain their body temperature well under cold exposure. At the molecular level, we found that the miR17-92 cluster targets Rb1, a beige cell repressor in WAT. The present study reveals a critical role for the miR17-92 cluster in regulating WAT browning. These results may be helpful for better understanding the function of beige fat, which could compensate for the lack of BAT in humans, and may open new avenues for combatting metabolic syndrome.

scholarly journals The role of rare innate immune cells in Type 2 immune activation against parasitic helminths

Parasitology ◽  
2017 ◽  
Vol 144 (10) ◽  
pp. 1288-1301 ◽  
Author(s):  
LAUREN M. WEBB ◽  
ELIA D. TAIT WOJNO
Keyword(s):  
Immune Cells ◽  
Low Frequency ◽  
Cell Types ◽  
Innate Immune ◽  
Lymphoid Cells ◽  
Innate Immune Cells ◽  
Helminth Parasites ◽  
Parasitic Helminths ◽  
Group 2

SUMMARYThe complexity of helminth macroparasites is reflected in the intricate network of host cell types that participate in the Type 2 immune response needed to battle these organisms. In this context, adaptive T helper 2 cells and the Type 2 cytokines interleukin (IL)-4, IL-5, IL-9 and IL-13 have been the focus of research for years, but recent work has demonstrated that the innate immune system plays an essential role. Some innate immune cells that promote Type 2 immunity are relatively abundant, such as macrophages and eosinophils. However, we now appreciate that more rare cell types including group 2 innate lymphoid cells, basophils, mast cells and dendritic cells make significant contributions to these responses. These cells are found at low frequency but they are specialized to their roles – located at sites such as the skin, lung and gut, where the host combats helminth parasites. These cells respond rapidly and robustly to worm antigens and worm-induced damage to produce essential cytokines, chemokines, eicosanoids and histamine to activate damaged epithelium and to recruit other effectors. Thus, a greater understanding of how these cells operate is essential to understand how the host protects itself during helminth infection.

scholarly journals The Effect and Regulatory Mechanism of High Mobility Group Box-1 Protein on Immune Cells in Inflammatory Diseases

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1044
Author(s):  
Yun Ge ◽  
Man Huang ◽  
Yong-ming Yao
Keyword(s):  
Immune Cells ◽  
Molecular Mechanisms ◽  
Immune Cell ◽  
Therapeutic Potential ◽  
Inflammatory Diseases ◽  
Critical Role ◽  
High Mobility ◽  
Cell Types ◽  
High Mobility Group ◽  
High Mobility Group Protein

High mobility group box-1 protein (HMGB1), a member of the high mobility group protein superfamily, is an abundant and ubiquitously expressed nuclear protein. Intracellular HMGB1 is released by immune and necrotic cells and secreted HMGB1 activates a range of immune cells, contributing to the excessive release of inflammatory cytokines and promoting processes such as cell migration and adhesion. Moreover, HMGB1 is a typical damage-associated molecular pattern molecule that participates in various inflammatory and immune responses. In these ways, it plays a critical role in the pathophysiology of inflammatory diseases. Herein, we review the effects of HMGB1 on various immune cell types and describe the molecular mechanisms by which it contributes to the development of inflammatory disorders. Finally, we address the therapeutic potential of targeting HMGB1.

scholarly journals T-cells play the classics with a different spin

2014 ◽  
Vol 25 (11) ◽  
pp. 1699-1703 ◽  
Author(s):  
Michael L. Dustin
Keyword(s):  
T Cells ◽  
Plasma Membrane ◽  
Immune Cells ◽  
Cell Biology ◽  
Immunological Synapse ◽  
Cell Communication ◽  
Intraflagellar Transport ◽  
Cell Types ◽  
Immune Synapse ◽  
And Function

The immune system uses much of the classic machinery of cell biology, but in ways that put a different spin on organization and function. Striking recent examples include the demonstration of intraflagellar transport protein and hedgehog contributions to the immune synapse, even though immune cells lack a primary cilium that would be the typical setting for this machinery. In a second example, lymphocytes have their own subfamily of integrins, the β2 subfamily, and only integrins in this family form a stable adhesion ring using freely mobile ligands, a key feature of the immunological synapse. Finally, we showed recently that T-cells use endosomal sorting complexes required for transport (ESCRTs) at the plasma membrane to generate T-cell antigen receptor–enriched microvesicles. It is unusual for the ESCRT pathway to operate at the plasma membrane, but this may allow a novel form of cell–cell communication by providing a multivalent ligand for major histocompatibility complex–peptide complexes and perhaps other receptors on the partnering B-cell. Immune cells are thus an exciting system for novel cell biology even with classical pathways that have been studied extensively in other cell types.

scholarly journals GIPR Signaling in Immune Cells Maintains Metabolically Beneficial Type 2 Immune Responses in the White Fat From Obese Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Irina Efimova ◽  
Inbar Steinberg ◽  
Isabel Zvibel ◽  
Anat Neumann ◽  
Dana Fernanda Mantelmacher ◽  
...  
Keyword(s):  
Immune Cells ◽  
Energy Homeostasis ◽  
Immune Cell ◽  
Lymphoid Cells ◽  
Altered Expression ◽  
Peripheral Tissues ◽  
Type 2 Immunity ◽  
Group 2 ◽  
White Fat

Glucose-dependent insulinotropic polypeptide (GIP) communicates information on energy availability from the gut to peripheral tissues. Disruption of its signaling in myeloid immune cells during high-fat diet (HFD)-induced obesity impairs energy homeostasis due to the unrestrained metabolically deleterious actions of S100A8/A9 alarmin. White adipose tissue (WAT) type 2 immune cell networks are important for maintaining metabolic and energy homeostasis and limiting obesity-induced inflammation. Nevertheless, the consequences of losing immune cell GIP receptor (GIPR) signaling on type 2 immunity in WAT remains unknown. Bone marrow (BM) chimerism was used to generate mice with GIPR (Gipr-/- BM) and GIPR/S100A8/A9 (Gipr-/-/S100a9-/- BM) deletion in immune cells. These mice were subjected to short (5 weeks) and progressive (14 weeks) HFD regimens. GIPR-deficiency was also targeted to myeloid cells by crossing Giprfl/fl mice and Lyz2cre/+ mice (LysMΔGipr). Under both short and progressive HFD regimens, Gipr-/- BM mice exhibited altered expression of key type 2 immune cytokines in the epididymal visceral WAT (epiWAT), but not in subcutaneous inguinal WAT. This was further linked to declined representation of type 2 immune cells in epiWAT, such as group 2 innate lymphoid cells (ILC2), eosinophils, and FOXP3+ regulatory T cells (Tregs). Co-deletion of S100A8/A9 in Gipr-/- immune cells reversed the impairment of type 2 cytokine expression in epiWAT, suggesting a mechanistic role for this alarmin in type 2 immune suppression. LysMΔGipr mice on HFD also displayed altered expression of type 2 immune mediators, highlighting that GIPR-deficiency in myeloid immune cells is responsible for the impairment of type 2 immune networks. Finally, abrogated GIPR signaling in immune cells also affected adipocyte fraction cells, inducing their increased production of the beiging interfering cytokine IL-10 and stress- related type 2 cytokine IL-13. Collectively, these findings attribute an important role for GIPR in myeloid immune cells in supporting WAT type 2 immunity.

scholarly journals Immunoregulatory Functions of Interferons During Genital HSV-2 Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Emily Feng ◽  
Elizabeth Balint ◽  
Fatemah Vahedi ◽  
Ali A. Ashkar
Keyword(s):  
Immune Cells ◽  
Reproductive Tract ◽  
Critical Role ◽  
Female Reproductive Tract ◽  
Type I ◽  
Local Immune Response ◽  
Disease Symptoms ◽  
Sexually Transmitted ◽  
Simplex Virus

Herpes simplex virus type 2 (HSV-2) infection is one of the most prevalent sexually transmitted infections that disproportionately impacts women worldwide. Currently, there are no vaccines or curative treatments, resulting in life-long infection. The mucosal environment of the female reproductive tract (FRT) is home to a complex array of local immune defenses that must be carefully coordinated to protect against genital HSV-2 infection, while preventing excessive inflammation to prevent disease symptoms. Crucial to the defense against HSV-2 infection in the FRT are three classes of highly related and integrated cytokines, type I, II, and III interferons (IFN). These three classes of cytokines control HSV-2 infection and reduce tissue damage through a combination of directly inhibiting viral replication, as well as regulating the function of resident immune cells. In this review, we will examine how interferons are induced and their critical role in how they shape the local immune response to HSV-2 infection in the FRT.

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