T he metabolic syndrome comprises a cluster of risk factors, including obesity, insulin resistance, hepatic steatosis, and dyslipidemia. It is associated with a variety of cardiovascular diseases such as atherosclerosis, myocardial infarction, and stroke.1 Chronic, low-grade inflammation in key metabolic organs such as the liver and visceral adipose tissue (VAT) Background-Costimulatory cascades such as the CD40L-CD40 dyad enhance immune cell activation and inflammation during atherosclerosis. Here, we tested the hypothesis that CD40 directly modulates traits of the metabolic syndrome in diet-induced obesity in mice. Methods and Results-To induce the metabolic syndrome, wild-type or CD40 −/− mice consumed a high-fat diet for 20 weeks. Unexpectedly, CD40−/− mice exhibited increased weight gain, impaired insulin secretion, augmented accumulation of inflammatory cells in adipose tissue, and enhanced proinflammatory gene expression. This proinflammatory and adverse metabolic phenotype could be transplanted into wild-type mice by reconstitution with CD40-deficient lymphocytes, indicating a major role for CD40 in T or B cells in this context. Conversely, therapeutic activation of CD40 signaling by the stimulating antibody FGK45 abolished further weight gain during the study, lowered glucose levels, improved insulin sensitivity, and suppressed adipose tissue inflammation. Mechanistically, CD40 activation decreased the expression of proinflammatory cytokines in T cells but not in B cells or macrophages. Finally, repopulation of lymphocyte-free Rag1 −/− mice with CD40 −/− T cells provoked dysmetabolism and inflammation, corroborating a protective role of CD40 on T cells in the metabolic syndrome. Finally, levels of soluble CD40 showed a positive association with obesity in humans, suggesting clinical relevance of our findings. Conclusions-We present the surprising finding that CD40 deficiency on T cells aggravates whereas activation of CD40 signaling improves adipose tissue inflammation and its metabolic complications. Therefore, positive modulation of the CD40 pathway might describe a novel therapeutic concept against cardiometabolic disease. T-regulatory (T reg ) cells, CD8 + T cells, and related chemokines and cytokines such as RANTES (regulated on activation normal T cell expressed and secreted) and interferon-γ (IFNγ) colocalize within the inflammatory cell compartment in adipose tissue. 7 In lean adipose tissue, the vast majority of T lymphocytes share features of anti-inflammatory, interleukin (IL)-13-, IL-4-, and IL-10-secreting Th2 or T reg cells. 8In obesity, proinflammatory Th1 cells expressing IFNγ overwhelm Th2 cells.9 Th1 cells, in turn, activate proinflammatory cytokine-secreting macrophages and promote their conversion from M2-like, IL-10-secreting, alternatively activated macrophages to classically activated, M1-like macrophages. 10,11Despite description of the kinetics of cellular infiltration and the associated cytokine/chemokine profiles during the development of obesity, the underlying cause modu...

Objective— A solid body of evidence supports a role of extracellular ATP and its P2 receptors in innate and adaptive immunity. It promotes inflammation as a danger signal in various chronic inflammatory diseases. Thus, we hypothesize contribution of extracellular ATP and its receptor P2Y 2 in vascular inflammation and atherosclerosis. Approach and Results— Extracellular ATP induced leukocyte rolling, adhesion, and migration in vivo as assessed by intravital microscopy and in sterile peritonitis. To test the role of extracellular ATP in atherosclerosis, ATP or saline as control was injected intraperitoneally 3× a week in low-density lipoprotein receptor −/− mice consuming high cholesterol diet. Atherosclerosis significantly increased after 16 weeks in ATP-treated mice (n=13; control group, 0.26 mm2; ATP group, 0.33 mm2; P =0.01). To gain into the role of ATP-receptor P2Y 2 in ATP-induced leukocyte recruitment, ATP was administered systemically in P2Y 2 -deficient or P2Y 2 -competent mice. In P2Y 2 -deficient mice, the ATP-induced leukocyte adhesion was significantly reduced as assessed by intravital microscopy. P2Y 2 expression in atherosclerosis was measured by real-time polymerase chain reaction and immunohistochemistry and demonstrates an increased expression mainly caused by influx of P2Y 2 -expressing macrophages. To investigate the functional role of P2Y 2 in atherogenesis, P2Y 2 -deficient low-density lipoprotein receptor −/− mice consumed high cholesterol diet. After 16 weeks, P2Y 2 -deficient mice showed significantly reduced atherosclerotic lesions with decreased macrophages compared with P2Y 2 -competent mice (n=11; aortic arch: control group, 0.25 mm 2 ; P2Y 2 -deficient, 0.14 mm2; P =0.04). Mechanistically, atherosclerotic lesions from P2Y 2 -deficient mice expressed less vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 RNA. Conclusions— We show that extracellular ATP induces vascular inflammation and atherosclerosis via activation of P2Y 2 .

Objective-Nucleotides such as ATP, ADP, UTP, and UDP serve as proinflammatory danger signals via purinergic receptors on their release to the extracellular space by activated or dying cells. UDP binds to the purinergic receptor Y 6 (P2Y 6 ) and propagates vascular inflammation by inducing the expression of chemokines such as monocyte chemoattractant protein 1, interleukin-8, or its mouse homologsCCL1 (chemokine [C-C motif] ligand 1)/keratinocyte chemokine, CXCL2 (chemokine [C-X-C motif] ligand 2)/macrophage inflammatory protein 2, and CXCL5 (chemokine [C-X-C motif] ligand 5)/LIX, and adhesion molecules such as vascular cell adhesion molecule 1 and intercellular cell adhesion molecule 1. Thus, P2Y 6 contributes to leukocyte recruitment and inflammation in conditions such as allergic asthma or sepsis. Because atherosclerosis is a chronic inflammatory disease driven by leukocyte recruitment to the vessel wall, we hypothesized a role of P2Y 6 in atherogenesis. Approach and Results-Intraperitoneal stimulation of wild-type mice with UDP induced rolling and adhesion of leukocytes to the vessel wall as assessed by intravital microscopy. This effect was not present in P2Y 6 -deficient mice. Atherosclerotic aortas of low-density lipoprotein receptor-deficient mice consuming high-cholesterol diet for 16 weeks expressed significantly more transcripts and protein of P2Y 6 than respective controls. Finally, P2Y 6 −/− /low-density lipoprotein receptor-deficient mice consuming high-cholesterol diet for 16 weeks developed significantly smaller atherosclerotic lesions compared with P2Y 6 +/+ /low-density lipoprotein receptor-deficient mice. Bone marrow transplantation identified a crucial role of P2Y 6 on vascular resident cells, most likely endothelial cells, on leukocyte recruitment and atherogenesis. Atherosclerotic lesions of P2Y 6 -deficient mice contained fewer macrophages and fewer lipids as determined by immunohistochemistry. Mechanistically, RNA expression of vascular cell adhesion molecule 1 and interleukin-6 was decreased in these lesions and P2Y 6 -deficient macrophages took up less modified low-density lipoprotein cholesterol. 16 demonstrated that P2Y 6 promotes host defense by augmenting the expression of monocyte chemoattractant protein 1 (MCP-1) and guiding monocytes to the location of infection. Besides the chemokine-driven recruitment, also a direct chemoattractant activity of the UDP-P2Y 6 R axis has been described 17 for leukocytes. Thus, stimulation of the P2Y 6 R has been implicated with chronic inflammatory diseases. Indeed, selective inhibition or knockdown of P2Y 6 R reduced all cardinal features of experimental acute and chronic allergic asthma in mice. 18 Furthermore, P2Y 6 contributes to inflammation of intestinal mucosa promoting IL-8-dependent neutrophil recruitment. Conclusions-We 19Pyridoxal phosphate-6-azophenyl-2′,4′-disulfonic acid, a synthetic substance blocking several purinergic receptors including P2Y 6 , P2Y 4 , P2Y 11 , and purinergic receptors X (ion channels), reduced atherosclerosis in...

Background: The prevalence of heart failure (HF) with mildly reduced or preserved ejection fraction (EF) markedly increases with age, with older individuals disproportionately facing excess risk for mortality and hospitalization. Methods: The DELIVER trial (Dapagliflozin Evaluation to Improve the LIVEs of Patients With PReserved Ejection Fraction Heart Failure) randomized patients with New York Heart Association functional class II-IV and left ventricular EF >40% to either dapagliflozin or placebo for a median follow-up period of 2.3 years. We examined efficacy and safety outcomes by age categories (<55, 55-64, 65-74 and ≥75 years) and across age as a continuous measure. Results: Among 6,263 randomized patients (aged 40-99 years, mean age 71.7 ± 9.6 years), 338 (5.4%) were <55 years, 1,007 (16.1%) were 55-64 years, 2,326 (37.1%) were 65-74 years, and 2,592 (41.4%) were ≥75 years. Dapagliflozin reduced the risk of the primary composite outcome compared with placebo in all age categories (p interaction =0.95) and across the age spectrum as a continuous function (p interaction =0.76). Similar benefits were observed for the components of the primary outcome, with no significant interaction between randomized treatment and age category. Adverse events occurred more frequently with increasing age, but there were no significant differences in predefined safety outcomes between patients randomized to dapagliflozin and placebo across all age categories. Conclusions: In patients with HF and mildly reduced or preserved EF enrolled in DELIVER, Dapagliflozin reduced cardiovascular death or HF events across the spectrum of age, with a consistent safety profile, including among the traditionally under-treated older segment of patients ≥75 years. Clinical Trial Registration: URL: https://www.clinicaltrials.gov Unique identifier: NCT03619213