TLR4-dependant pro-inflammatory effects of HMGB1 on human adipocyte

High mobility group box-1 protein promotes astrocytic CCL5 production through the MAPK/NF-κB pathway following spinal cord injury

Astrocytes act as immune cells that can produce a series of chemokines to attract large numbers of leucocytes to the lesion site, where they contribute to excessive inflammation following spinal cord injury (SCI). However, the relevant regulatory mechanism involved in chemokine production by astrocytes has not been fully elucidated. In the present study, we examined the correlation between C-C motif chemokine ligand 5 (CCL5) and high mobility group box-1 protein (HMGB1) in a T8-T10 spinal cord contusion model. Our results revealed that SCI-induced CCL5 protein levels increased synchronously with the increase in HMGB1. Administration of an HMGB1-neutralizing antibody significantly reduced the protein expression of CCL5 in the context of SCI. An in vitro study revealed that HMGB1 binding with TLR2/4 receptors potently facilitates the production of CCL5 by astrocytes by activating the intracellular ERK/JNK-mediated NF-κB pathway. Furthermore, the HMGB1-induced release of CCL5 from astrocytes is involved in promoting microglia/macrophage accumulation and M1 polarization. The inhibition of HMGB1 activity reduces microglia/macrophage infiltration by decreasing the expression of CCL5 and improves motor functional recovery following SCI. Our results provide insights into the new functions of HMGB1-mediated astrocytic CCL5 production, which elicits inflammatory cell recruitment to the site of injury; this recruitment is associated with excessive inflammation activation. These data may provide a new therapeutic strategy for central nervous system (CNS) inflammation.

Asprosin Enhances Cytokine Production by a Co-Culture of Fully Differentiated Mature Adipocytes and Macrophages Leading to the Exacerbation of the Condition Typical of Obesity-Related Inflammation

Asprosin, a fasting-induced, glucogenic, and orexigenic adipokine, has gained popularity in recent years as a potential target in the fight against obesity and its complications. However, the contribution of asprosin to the development of moderate obesity-related inflammation remains still unknown. The present study aimed to evaluate the effect of asprosin on the inflammatory activation of adipocyte–macrophage co-cultures at various stages of differentiation. The study was performed on co-cultures of the murine 3T3L1 adipocyte and the RAW264.7 macrophage cell lines treated with asprosin before, during, and after 3T3L1 cell differentiation, with or without lipopolysaccharide (LPS) stimulation. Cell viability, overall cell activity, and the expression and release of key inflammatory cytokines were analyzed. In the concentration range of 50–100 nM, asprosin increased the pro-inflammatory activity in the mature co-culture and enhanced the expression and release of tumor necrosis factor α (TNF-α), high-mobility group box protein 1 (HMGB1), and interleukin 6 (IL-6). Macrophage migration was also increased, which could be related to the upregulated expression and release of monocyte chemoattractant protein-1 (MCP-1) by the adipocytes. In summary, asprosin exerted a pro-inflammatory effect on the mature adipocyte–macrophage co-culture and may contribute to the spread of moderate obesity-associated inflammation. Nevertheless, further research is needed to fully elucidate this process.

The potential role of the adipokine HMGB1 in obesity and insulin resistance. Novel effects on adipose tissue biology

Discovery of the adipose tissue as a major source of signaling molecules almost three decades ago set a novel physiological paradigm that paved the way for the identification of metabolic organs as endocrine organs. Adipocytes, the main adipose tissue cell type, do not only represent the principal site of energy storage in form of triglycerides, but also produce a variety of molecules for short and long distance intercellular communication, named adipokines, which coordinate systemic responses. Although the best known adipokines identified and characterized hitherto are leptin and adiponectin, novel adipokines are continuously being described, what have significantly helped to elucidate the role of adipocyte biology in obesity and associated comorbidities. One of these novel adipokines is high-mobility group box 1 (HMGB1), a ubiquitous nuclear protein that has been recently reported to be dysregulated in obese dysfunctional adipocytes. Although the classical function of HMGB1 is related to inflammation and immunity, acting as an alarmin, novel advances evidence an active implication of HMGB1 in tissue remodeling and fibrosis. This review summarizes the current evidence on the mechanisms controlling HMGB1 release, as well as its role as a regulator of adipocyte function and extracellular matrix remodeling, with special emphasis on the potential of this novel adipokine as a target in the obesity treatment.

Effects of diabetes on the development of radiation pneumonitis

Radiation pneumonia (RP) is a common adverse reaction to radiation therapy in patients with chest tumors. Recent studies have shown that diabetes mellitus (DM), which can cause systemic multisystem damage, specifically targets lungs, and the incidence of RP in patients with a history of diabetes is higher than that in other patients with tumors who have undergone radiotherapy. DM is an important risk factor for RP in tumor patients undergoing RT, and patients with DM should be treated with caution. This article reviews research on the clinical aspects, as well as the mechanism, of the effects of diabetes on RP and suggests future research needed to reduce RP.

LncRNA UC.360+ shRNA Improves Diabetic Cardiac Sympathetic Dysfunction Mediated by the P2X4 Receptor in the Stellate Ganglion

Diabetic cardiac autonomic neuropathy (DCAN) is a complication that affects more than 60% of diabetic patients. There is evidence for the involvement of P2X4 receptor in DCAN. This study showed that the expression of the long noncoding RNA (lncRNA) UC.360+ was increased in the stellate ganglion (SG) of type 2 diabetes mellitus (DM) rats, and in situ hybridization revealed a clear presence of UC.360+ in SG neurons. The potential roles of UC.360+ in DCAN and its relationship with P2X4 receptor in SG were further explored via application of the short hairpin RNA (shRNA) against lncRNA UC.360+ in DM rats. The abnormal cardiac sympathetic changes in diabetic rats were improved after treatment with lncRNA UC.360+ shRNA. In the SG of these shRNA-treated DM rats, the upregulation of P2X4, tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), and phosphorylated ERK1/2 was inhibited. Thus, lncRNA UC.360+ shRNA treatment may improve DCAN mediated by the P2X4 receptor in SG.

Adipose tissue inflammation and metabolic dysfunction in obesity

Several lines of preclinical and clinical research have confirmed that chronic low-grade inflammation of adipose tissue is mechanistically linked to metabolic disease and organ tissue complications in the overweight and obese organism. Despite this widely confirmed paradigm, numerous open questions and knowledge gaps remain to be investigated. This is mainly due to the intricately intertwined cross-talk of various pro- and anti-inflammatory signaling cascades involved in the immune response of expanding adipose depots, particularly the visceral adipose tissue. Adipose tissue inflammation is initiated and sustained over time by dysfunctional adipocytes that secrete inflammatory adipokines and by infiltration of bone marrow-derived immune cells that signal via production of cytokines and chemokines. Despite its low-grade nature, adipose tissue inflammation negatively impacts remote organ function, a phenomenon that is considered causative of the complications of obesity. The aim of this review is to broadly present an overview of adipose tissue inflammation by highlighting the most recent reports in the scientific literature and summarizing our overall understanding of the field. We also discuss key endogenous anti-inflammatory mediators and analyze their mechanistic role(s) in the pathogenesis and treatment of adipose tissue inflammation. In doing so, we hope to stimulate studies to uncover novel physiological, cellular, and molecular targets for the treatment of obesity.

Myeloma-Modified Adipocytes Exhibit Metabolic Dysfunction and a Senescence-Associated Secretory Phenotype

Bone marrow adipocytes (BMAd) have recently been implicated in accelerating bone metastatic cancers, such as acute myelogenous leukemia and breast cancer. Importantly, bone marrow adipose tissue (BMAT) expands with aging and obesity, two key risk factors in multiple myeloma disease prevalence, suggesting that BMAds may influence and be influenced by myeloma cells in the marrow. Here, we provide evidence that reciprocal interactions and cross-regulation of myeloma cells and BMAds play a role in multiple myeloma pathogenesis and treatment response. Bone marrow biopsies from patients with multiple myeloma revealed significant loss of BMAT with myeloma cell infiltration of the marrow, whereas BMAT was restored after treatment for multiple myeloma. Myeloma cells reduced BMAT in different preclinical murine models of multiple myeloma and in vitro using myeloma cell-adipocyte cocultures. In addition, multiple myeloma cells altered adipocyte gene expression and cytokine secretory profiles, which were also associated with bioenergetic changes and induction of a senescent-like phenotype. In vivo, senescence markers were also increased in the bone marrow of tumor-burdened mice. BMAds, in turn, provided resistance to dexamethasone-induced cell-cycle arrest and apoptosis, illuminating a new possible driver of myeloma cell evolution in a drug-resistant clone. Our findings reveal that bidirectional interactions between BMAds and myeloma cells have significant implications for the pathogenesis and treatment of multiple myeloma. Targeting senescence in the BMAd or other bone marrow cells may represent a novel therapeutic approach for treatment of multiple myeloma. SIGNIFICANCE: This study changes the foundational understanding of how cancer cells hijack the bone marrow microenvironment and demonstrates that tumor cells induce senescence and metabolic changes in adipocytes, potentially driving new therapeutic directions.

A Receptor of the Immunoglobulin Superfamily Regulates Adaptive Thermogenesis

Exquisite regulation of energy homeostasis protects from nutrient deprivation but causes metabolic dysfunction upon nutrient excess. In human and murine adipose tissue, the accumulation of ligands of the receptor for advanced glycation end products (RAGE) accompanies obesity, implicating this receptor in energy metabolism. Here, we demonstrate that mice bearing global- or adipocyte-specific deletion of Ager, the gene encoding RAGE, display superior metabolic recovery after fasting, a cold challenge, or high-fat feeding. The RAGE-dependent mechanisms were traced to suppression of protein kinase A (PKA)-mediated phosphorylation of its key targets, hormone-sensitive lipase and p38 mitogen-activated protein kinase, upon β-adrenergic receptor stimulation—processes that dampen the expression and activity of uncoupling protein 1 (UCP1) and thermogenic programs. This work identifies the innate role of RAGE as a key node in the immunometabolic networks that control responses to nutrient supply and cold challenges, and it unveils opportunities to harness energy expenditure in environmental and metabolic stress.

Hurtado del Pozo et al. show that the deletion of adipocyte RAGE, whose ligands accumulate in metabolic stress, protects from obesity and cold challenges through the modulation of protein kinase A activities. This work adds RAGE to the immunometabolic networks that regulate energy expenditure in environmental and metabolic stress.

Age-Dependent Changes of Adipokine and Cytokine Secretion From Rat Adipose Tissue by Endogenous and Exogenous Toll-Like Receptor Agonists

White adipose tissue but recently also brown adipose tissue have emerged as endocrine organs. Age-associated obesity is accompanied by prolonged and elevated lipopolysaccharide (LPS)-induced sickness symptoms and increased cytokine and adipokine levels in the circulation partially originating from adipose tissue. In the present study, ex vivo fat explants were used to investigate how the exogenous pathogen-associated molecular pattern (PAMP) LPS or the endogenous danger-associated molecular patterns (DAMPs) high mobility group box-1 protein (HMGB1) and biglycan modulate the release of cytokines and adipokines/batokines and, thus, could influence systemic and/or local inflammation. The response of adipose tissue (epididymal, retroperitoneal, subcutaneous, and brown) was compared between young lean and old obese rats (2 vs. 24 months old). LPS induced a strong interleukin (IL)-6 and tumor necrosis factor (TNF) alpha release into the supernatant of all adipose tissue types investigated. HMGB1 (subcutaneous) and biglycan (retroperitoneal) led to an increased release of IL-6 and TNFalpha (HMGB1) and decreased visfatin and adiponectin (biglycan) secretion from epididymal adipose tissue (young rats). Visfatin was also decreased by HMGB1 in retroperitoneal adipose tissue of old rats. We found significantly higher leptin (all fat pads) and adiponectin (subcutaneous) levels in supernatants of adipose tissue from old compared to young rats, whereas visfatin secretion showed the opposite. The expression of the biglycan receptor Toll-like receptor (TLR) 2 as well as the LPS and HMGB1 receptors TLR4 and receptor for advanced glycation end products (RAGE) were reduced with age (TLR4/RAGE) and by stimulation with their ligands (subcutaneous). Overall, we revealed that adipokines/adipose-tissue released cytokines show some modulation of their release caused by mediators of septic (batokines) and sterile inflammation with potential implication for acute and chronic disease. Moreover, aging may increase or decrease the release of fat-derived mediators. These data show that DAMPS and LPS locally modulate cytokine secretion while only DAMPS but not LPS can locally alter adipokine secretion during inflammation.

HMGB1-induced aberrant autophagy contributes to insulin resistance in granulosa cells in PCOS

Insulin resistance (IR) disrupts ovarian functions in polycystic ovary syndrome (PCOS). The contributing factors remains elusive. High mobility group box 1 (HMGB1), a damage-associated molecular pattern molecule, has been shown to be related to IR and autophagy, respectively, in peripheral tissues. Here, we investigated whether increased HMGB1 contributes to IR in granulosa cells of PCOS patients via induction of aberrant autophagy. Results showed that HMGB1 abundance in the follicular fluid was significantly increased with enhanced autophagy in granulosa cells in PCOS patients with IR. HMGB1 exacerbated autophagy in granulosa cells as evinced by increased LC3B II/I ratio and ATG7 as well as decreased p62, the markers for autophagy. Concurrently, HMGB1 impaired insulin sensitivities by attenuating the abundance of insulin receptor substrate-1, Akt phosphorylation, GLUT4 translocation, and glucose uptake in granulosa cells, which were reversed by blocking autophagy pathways with siRNA-mediated knockdown of ATG7 or with chloroquine and bafilomycin A1, the lysosome inhibitors. In conclusion, our results indicate that increased HMGB1 contributes to IR development in granulosa cells of PCOS patients, which is associated with exacerbation of autophagy by HMGB1. Control of HMGB1 production may be benefical for the improvement of insulin sensitivity in granulosa cells in PCOS.

Pattern Recognition Receptor-Mediated Chronic Inflammation in the Development and Progression of Obesity-Related Metabolic Diseases

Obesity-induced chronic inflammation is known to promote the development of many metabolic diseases, especially insulin resistance, type 2 diabetes mellitus, nonalcoholic fatty liver disease, and atherosclerosis. Pattern recognition receptor-mediated inflammation is an important determinant for the initiation and progression of these metabolic diseases. Here, we review the major features of the current understanding with respect to obesity-related chronic inflammation in metabolic tissues, focus on Toll-like receptors and nucleotide-binding oligomerization domain-like receptors with an emphasis on how these receptors determine metabolic disease progression, and provide a summary on the development and progress of PRR antagonists for therapeutic intervention.

Superiority of the Non-Glycosylated Form Over the Glycosylated Form of Irisin in the Attenuation of Adipocytic Meta-Inflammation: A Potential Factor in the Fight Against Insulin Resistance

Irisin is an adipomyokine that promotes the browning of white adipose tissue and exhibits protective potential against the development of insulin resistance and type 2 diabetes. In our bodies, it occurs in its glycosylated form (G-IR): its activity is still poorly understood, because the majority of studies have used its non-glycosylated counterpart (nG-IR). Glycosylation can affect protein function: therefore, the present study attempted to compare the actions of both forms of irisin toward inflammatory activation of the main component of adipose tissue. The study was carried out in a coculture of 3T3 adipocytes and RAW 264.7 macrophages maintained in the presence of nG-IR or G-IR. The impact on vitality and the expression and release of key inflammatory mediators important for insulin resistance and diabetes development were assessed. The studies showed that both forms effectively inhibited the expression and release of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, macrophage chemotactic protein (MCP)-1, high-mobility group box (HMGB1), leptin, and adiponectin. However, in the case of TNF-α, IL-1β, MCP-1, and HMGB1, the inhibition exerted by nG-IR was more prominent than that by G-IR. In addition, only nG-IR significantly inhibited macrophage migration. Here, nG-IR seemed to be the stronger inhibitor of the development of obesity-related inflammation; however, G-IR also had anti-inflammatory potential.

A Mechanistic Model of Gut-Brain Axis Perturbation and High-Fat Diet Pathways to Gut Microbiome Homeostatic Disruption, Systemic Inflammation, and Type 2 Diabetes

Type 2 diabetes (T2D) is a highly prevalent metabolic disease, affecting nearly 10% of the American population. Although the etiopathogenesis of T2D remains poorly understood, advances in DNA sequencing technologies have allowed for sophisticated interrogation of the human microbiome, providing insight into the role of the gut microbiome in the development and progression of T2D. An emerging body of research reveals that gut-brain axis (GBA) perturbations and a high-fat diet (HFD), along with other modifiable and nonmodifiable risk factors, contribute to gut microbiome homeostatic imbalance. Homeostatic imbalance or disruption increases gut wall permeability and facilitates translocation of endotoxins (lipopolysaccharides) into the circulation with resultant systemic inflammation. Chronic, low-grade systemic inflammation ensues with pro-inflammatory pathways activated, contributing to obesity, insulin resistance (IR), pancreatic β-cell decline, and, thereby, T2D. While GBA perturbations and HFD are implicated in provoking these conditions, prior mechanistic models have tended to examine HFD and GBA pathways exclusively without considering their shared pathways to T2D. Addressing this gap, this article proposes a mechanistic model informed by animal and human studies to advance scientific understanding of (1) modifiable and nonmodifiable risk factors for gut microbiome homeostatic disruption, (2) HFD and GBA pathways contributing to homeostatic disruption, and (3) shared GBA and HFD pro-inflammatory pathways to obesity, IR, β-cell decline, and T2D. The proposed mechanistic model, based on the extant literature, proposes a framework for studying the complex relationships of the gut microbiome to T2D to advance study in this promising area of research.

High mobility group box-1 induces pro-inflammatory signaling in human nucleus pulposus cells via toll-like receptor 4-dependent pathway

Intervertebral disc (IVD) degeneration (DD) is associated with low back pain, the leading cause of disability worldwide. Damage-associated molecular patterns (DAMPs) that contribute to inflammation and trigger DD have not been well characterized. Extracellular high mobility group box-1 (HMGB1) protein has been implicated as a potent DAMP and pro-inflammatory stimulus in the immune system. In this study, we show that HMGB1 and IL-6 levels increase in patients with advanced DD in comparison to early DD. This study further tested the hypothesis that HMGB1 promotes inflammatory signaling driving DD in human nucleus pulposus (NP) cells and tissue. Immunofluorescence and western blot analysis confirmed the expression of HMGB1 and its extracellular release by NP cells under cell stress. Gene expression and protein quantification indicate that HMGB1 stimulates the expression IL-6 and MMP-1 in a dose-dependent manner. The contributions of toll-like receptor (TLR) -2, -4 and receptor for advanced glycation end products (RAGE) as receptors mediating HMGB1 signaling was examined using small molecule inhibitors. Inhibition of TLR-4 signaling, with TAK-242, completely abrogated HMGB1 induced IL-6 and MMP-1 expression, whereas inhibition of TLR-2, with O-vanillin, or RAGE, with FPS-ZM1, had mild inhibitory effects. HMGB1 stimulation activated NF-ĸB signaling while TAK-242 co-treatment abrogated it. Lastly, effects of HMGB1 on matrix deposition was evaluated in a 3D culture system of human NP cells. These results implicate HMGB1 as a potent DAMP that promotes inflammation in NP cells and degradation of NP tissues. TLR4-HMGB1 axis is a potential major pathway to alleviate disc inflammation and mitigate DD. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

A long-term maternal diet transition from high-fat diet to normal fat diet during pre-pregnancy avoids adipose tissue inflammation in next generation

Recent studies have suggested that maternal high-fat (HF) diet caused inflammation changes in adipose tissue; however, it remains unclear if maternal diet intervention before pregnancy rescues such effects in offspring. To address this question, female mice were continued on a normal-fat (NF group), or a HF diet (HF group) or transitioned from a HF diet to a NF diet at 1 (H1N group), 5 (H5N group) or 9 weeks (H9N group) prior to pregnancy. Among the three intervention groups, the H9N offspring displayed less and steady body weight gain, and maintained glucose tolerance, whereas the H1N and H5N offspring showed exacerbate these phenotypes. The H1N and H5N, but not the H9N offspring, displayed adipocyte hypertrophy associated with increased expression of genes involved in fat deposition. The H1N and H5N, but not the H9N adipose tissue, displayed increased macrophage infiltration with enhanced expression of inflammatory cytokine genes. In addition, overactivation of the NF-κB and the JNK signaling were observed in the H1N adipose tissue. Overall, our study showed that a long-term but not a short- or medium-term diet intervention before pregnancy released offspring adipose tissue inflammation induced by maternal HF diet, which adds details in our understanding how the maternal environment either promotes or discourages onset of disease in offspring. Clinically, this study is of great value for providing evidence in the design of clinical trials to evaluate the urgently required intervention strategies to minimize the intergenerational cycle of obesity.

Ferulic acid may target MyD88-mediated pro-inflammatory signaling - Implications for the health protection afforded by whole grains, anthocyanins, and coffee

Higher dietary intakes of anthocyanins have been linked epidemiologically to decreased risk for metabolic syndrome, type 2 diabetes and cardiovascular events; clinical trials and rodent studies evaluating ingestion of anthocyanin-rich extracts confirm favorable effects of these agents on endothelial function and metabolic syndrome. However, these benefits of anthocyanins are lost in rats whose gut microbiome has been eliminated with antibiotic treatment - pointing to bacterial metabolites of anthocyanins as the likely protective agents. A human pharmacokinetic assessment of orally administered cyanidin-3-O-glucoside, a prominent anthocyanin, has revealed that, whereas this compound is minimally absorbed, ferulic acid (FA) is one of its primary metabolites that appears in plasma. FA is a strong antioxidant and phase 2 inducer that has exerted marked anti-inflammatory effects in a number of rodent and cell culture studies; in particular, FA is highly protective in rodent models of diet-induced weight gain and metabolic syndrome. FA, a precursor for lignan synthesis, is widely distributed in plant-based whole foods, mostly in conjugated form; whole grains are a notable source. Coffee ingestion boosts plasma FA owing to gastrointestinal metabolism of chlorogenic acid. Hence, it is reasonable to suspect that FA mediates some of the broad health benefits that have been associated epidemiologically with frequent consumption of whole grains, anthocyanins, coffee, and unrefined plant-based foods. The molecular basis of the anti-inflammatory effects of FA may have been clarified by a recent study demonstrating that FA can target the adaptor protein MyD88; this plays an essential role in pro-inflammatory signaling by most toll-like receptors and interleukin-1β. If feasible oral intakes of FA can indeed down-regulate MyD88-dependent signaling, favorable effects of FA on neurodegeneration, hypothalamic inflammation, weight gain, adipocyte and beta cell function, adiponectin secretion, vascular health, and cartilage and bone integrity can be predicted. Since FA is well tolerated, safe, and natural, it may have great potential as a protective nutraceutical, and clinical trials evaluating its effects are needed.

The function and mechanism of HMGB1 in lung cancer and its potential therapeutic implications

As a non-histone chromatin-associated protein, high-mobility group box-1 (HMGB1) performs a pivotal function in various human diseases, including autoimmune diseases, neurodegenerative diseases and cancer. Overexpression of HMGB1 has been demonstrated in numerous types of cancer, including breast cancer, colorectal cancer, lung cancer and hepatocellular carcinoma. However, the underlying mechanism of HMGB1 function in lung cancer remains to be elucidated. The present study aimed to analyze, and summarize the role and mechanism of HMGB1 in lung cancer by retrieving available literature regarding HMGB1 in association with lung cancer. It provides comprehensive information on the association of HMGB1 with the carcinogenesis and progression of lung cancer, and discusses the molecular mechanism of these processes. HMGB1 may induce tumorigenesis, metastasis and chemotherapy resistance in lung cancer. Overall, it is evident that HMGB1 serves an important role in the development and progression of lung cancer, and this review warrants further investigation into HMGB1 as a novel target for cancer therapy.

HMGB1, an innate alarmin, plays a critical role in chronic inflammation of adipose tissue in obesity

Obesity has emerged as an imminent global public health concern over the past several decades. It has now become evident that obesity is characterized by the persistent and low-grade inflammation in the adipose tissue, and serves as an independent risk factor for many metabolic disorders such as diabetes and cardiovascular disease. Particularly, adipocytes originated from obese mice and humans likely predominate necrosis upon stressful insults, leading to passive release of cellular contents including the high mobility group box 1 (HMGB1) into the extracellular milieu. Extracellular HMGB1 acts as an innate alarmin to stimulate the activation of resident immune cells in the adipose tissue. Upon activation, those resident immune cells actively secrete additional HMGB1, which in turn activates/recruits additional immune cells, and induces adipocyte death. This review summarizes those novel discoveries in terms of HMGB1 in the initiation and maintenance of chronic inflammatory state in adipose tissue in obesity, and discusses its potential application in clinical settings.

The EP3 Receptor/Gz Signaling Axis as a Therapeutic Target for Diabetes and Cardiovascular Disease

Cardiovascular disease is a common co-morbidity found with obesity-linked type 2 diabetes. Current pharmaceuticals for these two diseases treat each of them separately. Yet, diabetes and cardiovascular disease share molecular signaling pathways that are increasingly being understood to contribute to disease pathophysiology, particularly in pre-clinical models. This review will focus on one such signaling pathway: that mediated by the G protein-coupled receptor, Prostaglandin E2 Receptor 3 (EP3), and its associated G protein in the insulin-secreting beta-cell and potentially the platelet, Gz. The EP3/Gz signaling axis may hold promise as a dual target for type 2 diabetes and cardiovascular disease.