XOMA 052, an anti-IL-1β monoclonal antibody, prevents IL-1β-mediated insulin resistance in 3T3-L1 adipocytes

The role of IL-1 family cytokines in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is the primary cause of heart failure in patients with diabetes and is characterised by contractile dysfunction and left ventricular hypertrophy. The complex pathological and physiological mechanisms underlying DCM have contributed to a limited number of available treatment options. A substantial body of evidence has established that DCM is a low-grade inflammatory cardiovascular disorder, with the interleukin-1 (IL-1) family of cytokines playing crucial roles in initiating inflammatory responses and shaping innate and adaptive immunity. In this review, we aim to provide an overview of the underlying mechanisms of the IL-1 family and their relevance in DCM of various aetiologies. Furthermore, we highlighted potential therapeutic targets within the IL-1 family for the management of DCM.

Eye on the horizon: The metabolic landscape of the RPE in aging and disease

To meet the prodigious bioenergetic demands of the photoreceptors, glucose and other nutrients must traverse the retinal pigment epithelium (RPE), a polarised monolayer of cells that lie at the interface between the outer retina and the choroid, the principal vascular layer of the eye. Recent investigations have revealed a metabolic ecosystem in the outer retina where the photoreceptors and RPE engage in a complex exchange of sugars, amino acids, and other metabolites. Perturbation of this delicate metabolic balance has been identified in the aging retina, as well as in age-related macular degeneration (AMD), the leading cause of blindness in the Western world. Also common in the aging and diseased retina are elevated levels of cytokines, oxidative stress, advanced glycation end-products, increased growth factor signalling, and biomechanical stress - all of which have been associated with metabolic dysregulation in non-retinal cell types and tissues. Herein, we outline the role of these factors in retinal homeostasis, aging, and disease. We discuss their effects on glucose, mitochondrial, lipid, and amino acid metabolism in tissues and cell types outside the retina, highlighting the signalling pathways through which they induce these changes. Lastly, we discuss promising avenues for future research investigating the roles of these pathological conditions on retinal metabolism, potentially offering novel therapeutic approaches to combat age-related retinal disease.

IL-1 signaling pathway, an important target for inflammation surrounding in myocardial infarction

Acute myocardial infarction is an important cardiovascular disease worldwide. Although the mortality rate of myocardial infarction (MI) has improved dramatically in recent years due to timely treatment, adverse remodeling of the left ventricle continues to affect cardiac function. Various immune cells are involved in this process to induce inflammation and amplification. The infiltration of inflammatory cells in the infarcted myocardium is induced by various cytokines and chemokines, and the recruitment of leukocytes further amplifies the inflammatory response. As an increasing number of clinical anti-inflammatory therapies have achieved significant success in recent years, treating myocardial infarction by targeting inflammation may become a novel therapeutic option. In particular, successful clinical trials of canakinumab have demonstrated the important role of the inflammatory factor interleukin-1 (IL-1) in atherosclerosis. Targeted IL-1 therapy may decrease inflammation levels and improve cardiac function in patients after myocardial infarction. This article reviews the complex series of responses after myocardial infarction, including the involvement of inflammatory cells and the role of cytokines and chemokines, focusing on the progression of the IL-1 family in myocardial infarction as well as the performance of current targeted therapy drugs in experiments.

Current Vaccination Practice in Diabetic (Diabetes I) Patients

The worldwide prevalence of diabetes, an endocrine condition, is rising quickly. The alarming rise of diabetes in recent years has emerged as a major contributor to premature death and illness among persons of working age. The potential use of immunomodulatory drugs to prevent diabetes has been a source of worry in light of recent advances in our understanding of the role of autoimmune responses in the development of diabetes. Vaccines can work in a variety of ways, including by eliminating autoreactive T-cells or by blocking the connections between immune cells. Most diabetes vaccines that have been created so far have only been evaluated in animal models, with just a small number having undergone successful human trials. In this article, the authors also look at the clinical trial research that are currently being conducted to create a prototype diabetes vaccine.

Salsalate: a pleotropic anti-inflammatory drug in the treatment of diabetes, obesity, and metabolic diseases

Type two Diabetes Mellitus (T2DM) is a rising epidemic. Available therapeutic strategies have provided glycaemic control via HbA1c reduction but fail to provide clinically meaningful reduction in microvascular and macrovascular (cardiac, renal, ophthalmological, and neurological) complications. Inflammation is strongly linked to the pathogenesis of T2DM. Underlying inflammatory mechanisms include oxidative stress, endoplasmic reticulum stress amyloid deposition in the pancreas, lipotoxicity, and glucotoxicity. Molecular signalling mechanisms in chronic inflammation linked to obesity and diabetes include JANK, NF-kB, and AMPK pathways. These activated pathways lead to a production of various inflammatory cytokines, such as Interleukin (IL-6), tumor necrosis factor (TNF)-alpha, and C-reactive protein (CRP), which create a chronic low-grade inflammation and ultimately dysregulation of glucose homeostasis in the liver, skeletal muscle, and smooth muscle. Anti-inflammatory agents are being tested as anti-diabetic agents such as the IL-1b antagonist, Anakinra, the IL-1b inhibitor, Canakinuma, the IL-6 antagonists such as Tocilizumab, Rapamycin (Everolimus), and the IKK-beta kinase inhibitor, Salsalate. Salsalate is a century old safe anti-inflammatory drug used in the treatment of arthritis. Long-term safety and efficacy of Salsalate in the treatment of T2DM have been evaluated, which showed improved fasting plasma glucose and reduced HbA1C levels as well as reduced pro-inflammatory markers in T2DM patients. Current publication summarizes the literature review of pathophysiology of role of inflammation in T2DM and clinical efficacy and safety of Salsalate in the treatment of T2DM.

Coptis chinensis, and extracts of guava and mulberry leaves present good inhibiting potential on obesity and associated metabolic disorders in high-fat diet obesity mice model

This study aimed to investigate the anti-obesity effects of Coptis chinensis (CC), BALASAN (combinational guava leaf extract and mulberry leaf extract), and CC/BALASAN (CC/BAL) on high-fat diet-induced obese C57BL/6 mice and to explore possible mediating mechanisms in 3T3-L1 pre-adipocytes. Oil red-O stain was used to test the effects of CC, BALASAN, and CC/BAL on the differentiation of 3T3-L1 pre-adipocytes. Additionally, real-time PCR was used to detect the expression of genes involved in adipocyte differentiation and inflammation-related genes in adipose tissue of mice that were fed a high-fat diet. CC, BALASAN, and CC/BAL inhibited the differentiation of 3T3-L1 pre-adipocytes and exhibited excellent inhibitory ability against the expression of PPARγ and RXRα genes associated with adipocyte differentiation. Replenishing mice with a high-fat diet with CC, BALASAN, and CC/BAL reduced body weight gaining and blood glucose and plasma cholesterol levels. CC also effectively reduced liver weight, whereas BALASAN and CC/BAL had no inhibitory effect. In addition, CC effectively inhibited the expression of C/EBP-α in adipose tissue. Interestingly, BALASAN not only inhibited the expression of C/EBP-α, but also that of PPARγ, RXRα, and TNFα. Such data indicated that CC, BALASAN, and CC/BAL may have potentially beneficial effects against obesity and associated metabolic disorders by down-regulating the PPARγ/RXRα pathway.

Vaccine for Diabetes-Where Do We Stand?

Diabetes is an endocrinological disorder with a rapidly increasing number of patients globally. Over the last few years, the alarming status of diabetes has become a pivotal factor pertaining to morbidity and mortality among the youth as well as middle-aged people. Current developments in our understanding related to autoimmune responses leading to diabetes have developed a cause for concern in the prospective usage of immunomodulatory agents to prevent diabetes. The mechanism of action of vaccines varies greatly, such as removing autoreactive T cells and inhibiting the interactions between immune cells. Currently, most developed diabetes vaccines have been tested in animal models, while only a few human trials have been completed with positive outcomes. In this review, we investigate the undergoing clinical trial studies for the development of a prototype diabetes vaccine.

Bovine α-lactalbumin-derived peptides attenuate TNF-α-induced insulin resistance and inflammation in 3T3-L1 adipocytes through inhibiting JNK and NF-κB signaling

Bioactive peptides in bovine α-lactalbumin were isolated and identified, and the effects and mechanisms of peptide KILDK on insulin resistance in 3T3-L1 adipocytes were investigated. Mature 3T3-L1 adipocytes were stimulated with TNF-α to induce insulin resistance. Bovine α-lactalbumin hydrolysates (α-LAH) were subjected to stimulated gastrointestinal digestion and Caco-2 absorption, and GD-α-LAH and CA-α-LAH were obtained. Our results demonstrated that α-LAH, GD-α-LAH, and CA-α-LAH increased glucose uptake, enhanced Akt phosphorylation (Ser473), and decreased IRS-1 phosphorylation (Ser307) in insulin resistant 3T3-L1 adipocytes. Gel filtration chromatography and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI MS/MS) were used to separate and identify bioactive peptides. The identified peptide KILDK attenuated insulin resistance in 3T3-L1 adipocytes, which was attributed to the suppression of JNK phosphorylation (Thr183/Tyr185). Moreover, KILDK downregulated pro-inflammatory genes through blocking NF-κB signaling. Our findings suggested that bovine α-LAH might be a potential ingredient against insulin resistance.

IL-1β and IL-10 gene polymorphisms in women with gestational diabetes

AIMS

Gestational diabetes (GDM) is carbohydrate intolerance occurring in pregnant women. In the GDM pathogenesis, the low-grade inflammation plays a significant role. Various inflammatory mediators are considered to be risk factors leading to GDM development including cytokines. Studies suggest that some cytokines such as: IL-1β and IL-10 play an important role in GDM pathogenesis. The aim of the study was to examine the associations between IL-1β rs16944, and IL-10 rs1800872 gene polymorphisms and GDM.

METHODS

This study included 204 pregnant women with GDM and 207 pregnant women with normal glucose tolerance. The diagnosis of GDM was based on a 75-g oral glucose tolerance test administered at 24-28 weeks' gestation. Among the pregnant women with GDM, 152 (75%) were treated with diet control alone throughout the pregnancy, whereas the remaining 52 (25%) were treated with diet control and insulin until delivery.

RESULTS

There were no statistically significant differences in the distribution of IL-1β rs16944 and IL-10 rs1800872 between GDM and healthy women. However among women treated with insulin, we observed the increased frequency of IL-1β rs16944 AA genotype carriers. Additionally, we observed increased daily insulin requirement in women with IL-1β rs16944 AA genotype. Moreover, women with IL-10 rs1800872 AA genotype had higher body mass and BMI before pregnancy as well as higher body mass and BMI increase during pregnancy.

CONCLUSIONS

The results of our study suggest the association between IL-1β rs16944 AA genotype and increased frequency of the need of insulin treatment as well as increased daily insulin requirement.

Cellular senescence links aging and diabetes in cardiovascular disease

Aging is a powerful independent risk factor for cardiovascular diseases such as atherosclerosis and heart failure. Concomitant diabetes mellitus strongly reinforces this effect of aging on cardiovascular disease. Cellular senescence is a fundamental mechanism of aging and appears to play a crucial role in the onset and prognosis of cardiovascular disease in the context of both aging and diabetes. Senescent cells are in a state of cell cycle arrest but remain metabolically active by secreting inflammatory factors. This senescence-associated secretory phenotype is a trigger of chronic inflammation, oxidative stress, and decreased nitric oxide bioavailability. A complex interplay between these three mechanisms results in age- and diabetes-associated cardiovascular damage. In this review, we summarize current knowledge on cellular senescence and its secretory phenotype, which might be the missing link between aging and diabetes contributing to cardiovascular disease.

Targeting adipose tissue in the treatment of obesity-associated diabetes

Adipose tissue regulates numerous physiological processes, and its dysfunction in obese humans is associated with disrupted metabolic homeostasis, insulin resistance and type 2 diabetes mellitus (T2DM). Although several US-approved treatments for obesity and T2DM exist, these are limited by adverse effects and a lack of effective long-term glucose control. In this Review, we provide an overview of the role of adipose tissue in metabolic homeostasis and assess emerging novel therapeutic strategies targeting adipose tissue, including adipokine-based strategies, promotion of white adipose tissue beiging as well as reduction of inflammation and fibrosis.

Interleukin-1β-Targeted Vaccine Improves Glucose Control and β-Cell Function in a Diabetic KK-Ay Mouse Model

Interleukin-1β (IL-1β) has been implicated as a key proinflammatory cytokine involved in the pancreatic islet inflammation of type 2 diabetes mellitus (T2DM). Excess IL-1β impairs islet function by inducing insulin resistance and β-cell apoptosis. Therefore, specifically reducing IL-1β activity provides a therapeutic improvement for T2DM by sustaining the inhibition of IL-1β-mediated islet inflammation. In this study, we developed an IL-1β-targeted epitope peptide vaccine adjuvanted with polylactic acid microparticles (1βEPP) and applied it to a diabetic KK-Ay mouse model. Results showed that the 1βEPP elicited high antibody responses, which neutralized the biological activity of IL-1β, and induced barely detectable inflammatory activity. 1βEPP immunization reduced body weight gain, protected KK-Ay mice from hyperglycemia, improved glucose tolerance and insulin sensitivity, and decreased the serum levels of free fatty acids, total cholesterol and triglyceride. Moreover, 1βEPP restored β-cell mass; inhibited β-cell apoptosis; decreased the expression of IL-1β; and interrupted NF-κB activation by reducing IKKβ and pRelA levels. These studies indicated that the IL-1β-targeted vaccine may be a promising immunotherapeutic for T2DM treatment.

Interleukin-1 as a common denominator from autoinflammatory to autoimmune disorders: premises, perils, and perspectives

A complex web of dynamic relationships between innate and adaptive immunity is now evident for many autoinflammatory and autoimmune disorders, the first deriving from abnormal activation of innate immune system without any conventional danger triggers and the latter from self-/non-self-discrimination loss of tolerance, and systemic inflammation. Due to clinical and pathophysiologic similarities giving a crucial role to the multifunctional cytokine interleukin-1, the concept of autoinflammation has been expanded to include nonhereditary collagen-like diseases, idiopathic inflammatory diseases, and metabolic diseases. As more patients are reported to have clinical features of autoinflammation and autoimmunity, the boundary between these two pathologic ends is becoming blurred. An overview of monogenic autoinflammatory disorders, PFAPA syndrome, rheumatoid arthritis, type 2 diabetes mellitus, uveitis, pericarditis, Behçet's disease, gout, Sjögren's syndrome, interstitial lung diseases, and Still's disease is presented to highlight the fundamental points that interleukin-1 displays in the cryptic interplay between innate and adaptive immune systems.

Ghrelin augments the expressions and secretions of proinflammatory adipokines, VEGF120 and MCP-1, in differentiated 3T3-L1 adipocytes

Ghrelin is a physiological-active peptide with growth hormone-releasing activity, orexigenic activity, etc. In addition, the recent study has also suggested that ghrelin possesses the pathophysiological abilities related with type 2 diabetes. However, the ghrelin-direct-effects implicated in type 2 diabetes on peripheral tissues have been still unclear, whereas its actions on the central nervous system (CNS) appear to induce the development of diabetes. Thus, to assess its peripheral effects correlated with diabetes, we investigated the regulatory mechanisms about adipokines, which play a central role in inducing peripheral insulin resistance, secreted from mature 3T3-L1 adipocytes stimulated with ghrelin in vitro . The stimulation with 50 nmol/L ghrelin for 24 h resulted in the significant 1.9-fold increase on vascular endothelial growth factor-120 (VEGF(120)) releases (p < 0.01) and the 1.7-fold on monocyte chemoattractant protein-1 (MCP-1) (p < 0.01) from 3T3-L1 adipocytes, respectively, while ghrelin failed to enhance tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, IL-10 and adiponectin secretions. In addition, Akt phosphorylation on Ser473 and c-Jun NH2 -terminal protein kinase (JNK) phosphorylation on Thr183/Tyr185 were markedly enhanced 1.4-fold (p < 0.01) and 1.6-fold (p < 0.01) in the ghrelin-stimulated adipocytes, respectively. Furthermore, the treatment with LY294002 (50 μmol/L) and Wortmannin (10nmol/L), inhibitors of phosphatidylinositol 3-kinase (PI3K), significantly decreased the amplified VEGF(120) secretion by 29% (p < 0.01) and 28% (p < 0.01) relative to the cells stimulated by ghrelin alone, respectively, whereas these inhibitors had no effects on increased MCP-1 release. On the other hand, JNK inhibitor SP600125 (10 μmol/L) clearly reduced the increased MCP-1, but not VEGF(120), release by 35% relative to the only ghrelin-stimulated cells (p < 0.01). In conclusion, ghrelin can enhance the secretions of proinflammatory adipokines, VEGF(120) and MCP-1, but fails to affect IL-10 and adiponectin which are considered to be anti-inflammatory adipokines. Moreover, this augmented VEGF(120) release is invited through the activation of PI3K pathways and the MCP-1 is through JNK pathways. Consequently, our results strongly suggest that ghrelin can induce the development of diabetes via its direct-action in peripheral tissues as well as via in CNS.

Anti-inflammatory agents to treat or prevent type 2 diabetes, metabolic syndrome and cardiovascular disease

INTRODUCTION

There is a growing body of evidence to suggest that chronic silent inflammation is a key feature in abdominal obesity, metabolic syndrome, type 2 diabetes (T2DM) and cardiovascular disease (CVD). These observations suggest that pharmacological strategies, which reduce inflammation, may be therapeutically useful in treating obesity, type 2 diabetes and associated CVD.

AREA COVERED

The article covers novel strategies, using either small molecules or monoclonal antibodies. These strategies include: approaches targeting IKK-b-NF-kB (salicylates, salsalate), TNF-α (etanercept, infliximab, adalimumab), IL-1β (anakinra, canakinumab) and IL-6 (tocilizumab), AMP-activated protein kinase activators, sirtuin-1 activators, mammalian target of rapamycin inhibitors and C-C motif chemokine receptor 2 antagonists.

EXPERT OPINION

The available data supports the concept that targeting inflammation improves insulin sensitivity and β-cell function; it also ameliorates glucose control in insulin-resistant patients with inflammatory rheumatoid diseases as well in patients with metabolic syndrome or T2DM. Although promising, the observed metabolic effects remain rather modest in most clinical trials. The potential use of combined anti-inflammatory agents targeting both insulin resistance and insulin secretion appears appealing but remains unexplored. Large-scale prospective clinical trials are underway to investigate the safety and efficacy of different anti-inflammatory drugs. Further evidence is needed to support the concept that targeting inflammation pathways may represent a valuable option to tackle the cardiometabolic complications of obesity.

Cellular senescence and the senescent secretory phenotype in age-related chronic diseases

PURPOSE OF REVIEW

Possible mechanisms in cellular senescence and the senescence-associated secretory phenotype (SASP) that drive and promote chronic inflammation in multiple age-related chronic diseases are considered.

RECENT FINDINGS

A series of studies about the SASP indicate that senescent cells may be involved in the development of chronic inflammatory diseases associated with aging.

SUMMARY

Aging is a complex biological process accompanied by a state of chronic, low-grade, 'sterile' inflammation, which is a major contributor to the development of many age-related chronic disorders including atherosclerosis, osteoarthritis, Alzheimer's disease, type 2 diabetes, cancers, and others. It appears that cellular senescence plays a role in causing inflammation through the SASP. A better understanding of the contribution of senescent cells to the pathologies of chronic inflammatory disorders could have potentially profound diagnostic and therapeutic implications.

Activation of inflammasomes in adipose tissue of women with gestational diabetes

Gestational diabetes mellitus (GDM) is characterised by maternal peripheral insulin resistance, increased inflammation, and increasing levels of circulating free fatty acids (FFAs) and advanced glycation endproducts (AGEs). Caspase-1 is a key component of the inflammasome, which is activated upon cellular infection or stress to trigger the maturation IL-1β, a pro-inflammatory cytokine that mediated insulin resistance. The aim of this study was to determine whether the inflammasome is activated in adipose tissue from women with gestational diabetes mellitus (GDM) and if it interferes with the insulin signalling pathway leading to the insulin resistance that is evident in GDM. Protein expression of active caspase-1 and mature IL-1β secretion was increased in adipose tissue of women with GDM. Treatment of adipose tissue with IL-1β decreased insulin-stimulated phosphorylation of IRS-1, GLUT-4 expression and glucose uptake. Low-grade inflammation (induced by LPS), the FFA palmitate and AGE conjugated to BSA (AGE-BSA), induced IL-1β secretion via inflammasome activation. In conclusion, the present findings describe an important role for adipose tissue inflammasome activation in the development of insulin resistance associated in pregnancies complicated by GDM.