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Evidence from animal models and human studies clearly demonstrate that sodium-glucose cotransporter-2 (SGLT2) inhibitors have systemic and tissue-specific anti-inflammatory effects that may be independent of glycemic control and weight loss. SGLT2 inhibitors may achieve their anti-inflammatory effects through various mechanisms, including reduction of reactive oxygen species, inflammasome activation, intracellular sodium and calcium levels, circulating uric acid, and mitochondrial dysfunction. The direct and indirect mitigation of inflammatory pathways by SGLT2 inhibitors may partially explain their cardiac and renoprotective effects. However, this remains to be formally demonstrated in human studies. Inflammation plays an essential role and is a common feature in the pathogenesis of many chronic diseases. The exact mechanisms through which sodium-glucose cotransporter-2 (SGLT2) inhibitors achieve their much-acclaimed clinical benefits largely remain unknown. In this review, we detail the systemic and tissue- or organ-specific anti-inflammatory effects of SGLT2 inhibitors using evidence from animal and human studies. We discuss the potential pathways through which SGLT2 inhibitors exert their anti-inflammatory effects, including oxidative stress, mitochondrial, and inflammasome pathways. Finally, we highlight the need for further investigation of the extent of the contribution of the anti-inflammatory effects of SGLT2 inhibition to improvements in cardiometabolic and renal outcomes in clinical studies. [ABSTRACT FROM AUTHOR]

Metabolic effects of glucagon-like peptide 1 (GLP-1) receptor agonists are confounded by weight loss and not fully recapitulated by increasing endogenous GLP-1. We tested the hypothesis that GLP-1 receptor (GLP-1R) agonists exert weight loss–independent, GLP-1R–dependent effects that differ from effects of increasing endogenous GLP-1. Individuals with obesity and prediabetes were randomized to receive for 14 weeks the GLP-1R agonist liraglutide, a hypocaloric diet, or the dipeptidyl peptidase 4 (DPP-4) inhibitor sitagliptin. The GLP-1R antagonist exendin(9-39) and placebo were administered in a two-by-two crossover study during mixed-meal tests. Liraglutide and diet, but not sitagliptin, caused weight loss. Liraglutide improved insulin sensitivity measured by HOMA for insulin resistance (HOMA-IR), the updated HOMA model (HOMA2), and the Matsuda index after 2 weeks, prior to weight loss. Liraglutide decreased fasting and postprandial glucose levels, and decreased insulin, C-peptide, and fasting glucagon levels. In contrast, diet-induced weight loss improved insulin sensitivity by HOMA-IR and HOMA2, but not the Matsuda index, and did not decrease glucose levels. Sitagliptin increased endogenous GLP-1 and GIP values without altering insulin sensitivity or fasting glucose levels, but decreased postprandial glucose and glucagon levels. Notably, sitagliptin increased GIP without altering weight. Acute GLP-1R antagonism increased glucose levels in all groups, increased the Matsuda index and fasting glucagon level during liraglutide treatment, and increased endogenous GLP-1 values during liraglutide and sitagliptin treatments. Thus, liraglutide exerts rapid, weight loss–independent, GLP-1R–dependent effects on insulin sensitivity that are not achieved by increasing endogenous GLP-1. Article Highlights: Metabolic benefits of glucagon-like peptide 1 (GLP-1) receptor agonists are confounded by weight loss and are not fully achieved by increasing endogenous GLP-1 through dipeptidyl peptidase 4 (DPP-4) inhibition. We investigated weight loss–independent, GLP-1 receptor (GLP-1R)–dependent metabolic effects of liraglutide versus a hypocaloric diet or the DPP-4 inhibitor sitagliptin. GLP-1R antagonism with exendin(9-39) was used to assess GLP-1R–dependent effects during mixed meals. Liraglutide improved insulin sensitivity and decreased fasting and postprandial glucose prior to weight loss, and these benefits were reversed by exendin(9-39). GLP-1R agonists exert rapid, weight loss–independent, GLP-1R–dependent effects on insulin sensitivity not achieved by increasing endogenous GLP-1. [ABSTRACT FROM AUTHOR]

Aim: To test the hypothesis that glucagon‐like peptide‐1 receptor (GLP‐1R) agonists have beneficial effects on vascular endothelial function, fibrinolysis and inflammation through weight loss‐independent mechanisms. Materials and Methods: Individuals with obesity and prediabetes were randomized to 14 weeks of the GLP‐1R agonist liraglutide, hypocaloric diet or the dipeptidyl peptidase‐4 inhibitor sitagliptin in a 2:1:1 ratio. Treatment with drug was double blind and placebo‐controlled. Measurements were made at baseline, after 2 weeks prior to significant weight loss and after 14 weeks. The primary outcomes were measures of endothelial function: flow‐mediated vasodilation (FMD), plasminogen activator inhibitor‐1 (PAI‐1) and urine albumin‐to‐creatinine ratio (UACR). Results: Eighty‐eight individuals were studied (liraglutide N = 44, diet N = 22, sitagliptin N = 22). Liraglutide and diet reduced weight, insulin resistance and PAI‐1, while sitagliptin did not. There was no significant effect of any treatment on endothelial vasodilator function measured by FMD. Post hoc subgroup analyses in individuals with baseline FMD below the median, indicative of greater endothelial dysfunction, showed an improvement in FMD by all three treatments. GLP‐1R antagonism with exendin (9‐39) increased fasting blood glucose but did not change FMD or PAI‐1. There was no effect of treatment on UACR. Finally, liraglutide, but not sitagliptin or diet, reduced the chemokine monocyte chemoattractant protein‐1 (MCP‐1). Conclusion: Liraglutide and diet reduce weight, insulin resistance and PAI‐1. Liraglutide, sitagliptin and diet do not change FMD in obese individuals with prediabetes with normal endothelial function. Liraglutide alone lowers the pro‐inflammatory and pro‐atherosclerotic chemokine MCP‐1, indicating that this beneficial effect is independent of weight loss. [ABSTRACT FROM AUTHOR]

Dipeptidyl peptidase‐4 (DPP‐4) inhibitors increase endogenous glucagon‐like peptide‐1 (GLP‐1). We hypothesized that genetic variation in the gene encoding the GLP‐1 receptor (GLP1R) could affect the metabolic response to DPP‐4 inhibition. To evaluate the relationship between the GLP1R rs6923761 variant (G‐to‐A nucleic acid substitution) and metabolic responses, we performed mixed meal studies in individuals with type 2 diabetes mellitus and hypertension after 7‐day treatment with placebo and the DPP‐4 inhibitor sitagliptin. This analysis is a substudy of NCT02130687. The genotype frequency was 13:12:7 GG:GA:AA among individuals of European ancestry. Postprandial glucose excursion was significantly decreased in individuals carrying the rs6923761 variant (GA or AA) as compared with GG individuals during both placebo (P = 0.001) and sitagliptin treatment (P = 0.045), while intact GLP‐1 levels were similar among the genotype groups. In contrast, sitagliptin lowered postprandial glucose to a greater degree in GG as compared with GA/AA individuals (P = 0.035). The relationship between GLP1R rs6923761 genotype and therapies that modulate GLP‐1 signalling merits study in large populations. [ABSTRACT FROM AUTHOR]

T cells are essential for immune defenses against pathogens, such that viability of naïve T cells before antigen encounter is critical to preserve a polyclonal repertoire and prevent immunodeficiencies. The viability of naive T cells before antigen recognition is ensured by IL-7, which drives expression of the prosurvival factor Bcl-2. Quiescent naive T cells have low basal activity of the transcription factor NF-κB, which was assumed to have no functional consequences. In contrast to this postulate, our data show that basal nuclear NF-κB activity plays an important role in the transcription of IL-7 receptor a-subunit (CD127), enabling responsiveness of naive T cells to the prosurvival effects of IL-7 and allowing T-cell persistence in vivo. Moreover, we show that this property of basal NF-κB activity is shared by mouse and human naïve T cells. Thus, NF-κB drives a distinct transcriptional program in T cells before antigen encounter by controlling susceptibility to IL-7. Our results reveal an evolutionarily conserved role of NF-κB in T cells before antigenic stimulation and identify a novel molecular pathway that controls T-cell homeostasis. [ABSTRACT FROM AUTHOR]

• sEH inhibition decreases adipose tissue IFNγ-producing T helper cells and secreted TNFα. • sEH inhibition does not affect adipose tissue IL-17A production. • Modulating the sEH/EET pathway has anti-inflammatory potential in humans. Adipose tissue contains a complex immune environment and is a central contributor to heightened systemic inflammation in obese persons. Epoxyeicosatrienoic acids (EETs) are lipid signaling molecules that decrease inflammation in obese animals, but their effect on inflammation in humans is unknown. The enzyme soluble epoxide hydrolase (sEH) hydrolyzes EETs to less active diols, and we hypothesized that pharmacologic sEH inhibition would decrease adipose inflammation in obese individuals. We treated obese prediabetic adults with the sEH inhibitor GSK2256294 versus placebo in a crossover design, collected subcutaneous abdominal adipose tissue via lipoaspiration and characterized the tissue T cell profile. Treatment with GSK2256294 decreased the percentage of pro-inflammatory T cells producing interferon-gamma (IFNγ), but not interleukin (IL)-17A, and decreased the amount of secreted tumor necrosis factor-alpha (TNFα). Understanding the contribution of the EET/sEH pathway to inflammation in obesity could lead to new strategies to modulate adipose and systemic inflammation. [ABSTRACT FROM AUTHOR]

Summary: CD8α+ dendritic cells (DCs) are important in vivo for cross-presentation of antigens derived from intracellular pathogens and tumors. Additionally, secretion of interleukin-12 (IL-12) by CD8α+ DCs suggests a role for these cells in response to Toxoplasma gondii antigens, although it remains unclear whether these cells are required for protection against T. gondii infection. Toward this goal, we examined T. gondii infection of Batf3 −/− mice, which selectively lack only lymphoid-resident CD8α+ DCs and related peripheral CD103+ DCs. Batf3 −/− mice were extremely susceptible to T. gondii infection, with decreased production of IL-12 and interferon-γ. IL-12 administration restored resistance in Batf3−/− mice, and mice in which IL-12 production was ablated only from CD8α+ DCs failed to control infection. These results reveal that the function of CD8α+ DCs extends beyond a role in cross-presentation and includes a critical role for activation of innate immunity through IL-12 production during T. gondii infection. [ABSTRACT FROM AUTHOR]

Aims: To investigate the hypothesis that weight loss with the glucagon‐like peptide‐1 receptor agonist (GLP‐1RA) liraglutide alone would lead to a greater reduction in the proportion of fat to lean tissue mass when compared to caloric restriction (CR) alone, as well as when compared to treatment with sitagliptin, a dipeptidyl peptidase‐4 (DPP‐4) inhibitor, that also enhances GLP‐1 activity ‐ to determine the independent effects of each treatment. Methods: A total of 88 adults with obesity and prediabetes were randomized to 14 weeks of intervention with CR (−390 kcal/d), liraglutide (1.8 mg/d), or the dipeptidyl peptidase‐4 inhibitor sitagliptin (100 mg/d) as a weight‐neutral comparator. Changes between groups in appetite and hunger ratings measured via visual analogue scales, dietary intakes, body weight, body composition via dual energy x‐ray absorptiometry, and resting energy expenditure via indirect calorimetry were assessed using the Kruskal‐Wallis test or Pearson's chi‐squared test. Results: Weight loss ≥5% of baseline body weight occurred in 44% of participants in the CR group, 22% of the liraglutide group and 5% of the sitagliptin group (p = 0.02). The ratio of fat to lean mass decreased by 6.5% in the CR group, 2.2% in the liraglutide group, and 0% in the sitagliptin group (p = 0.02). Visceral fat reduced by 9.5% in the CR group, 4.8% in the liraglutide group, and 0% in the sitagliptin group (p = 0.04). A spontaneous reduction in dietary simple carbohydrates in the CR group was associated with improved homeostatic model assessment of insulin resistance score (HOMA‐IR). Conclusions: Although both liraglutide and CR are valuable strategies for cardiometabolic risk reduction, CR was associated with greater weight loss and more favourable improvements in body composition than treatment with liraglutide alone. Differences in the response to each of these interventions enables patients to be stratified to the most optimal intervention for their personal risk factors. [ABSTRACT FROM AUTHOR]

Serum periostin is lower in asthmatics with T2DM using GLP-1RAs compared to alternative diabetes therapies. Prior studies identifying candidate biomarkers of GLP-1RA use critically lacked inclusion of patients with asthma.[[4]] Increasing data support periostin as a potential biomarker of GLP-1RA use. In conclusion, GLP-1RA use may attenuate the increased risk for poor asthma outcomes in patients with metabolic dysregulation and obesity by impacting pathways relevant to airway inflammation in humans. Consistent with prior asthma literature, patients with comorbid asthma (Biobank cohort) had higher mean levels of periostin than the non-asthma patients (RCT cohort). [Extracted from the article]

Supplemental Digital Content is Available in the Text. Objective: Fat redistribution from subcutaneous adipose tissue (SAT) to the abdominal viscera, pericardium, liver, and skeletal muscle contributes to the rising burden of cardiometabolic disease among persons with HIV (PWH). Previous studies found SAT inflammation in PWH impairs lipid storage and persists despite plasma viral suppression on antiretroviral therapy (ART). In this study, we identified SAT immune-related genes associated with ectopic fat deposition in PWH on long-term ART. Design and methods: A total of 92 PWH with well-controlled viremia underwent computed tomography imaging and abdominal SAT biopsy for gene expression analysis. SAT gene expression was measured using a NanoString panel of 255 immune-related genes. Associations between gene expression and computed tomography measurements of the volume and attenuation (radiodensity) of metabolically relevant ectopic fat depots were assessed using multivariable linear regression and network analysis. Results: Greater SAT volume was associated with higher visceral and pericardial adipose tissue volume, but lower skeletal muscle attenuation. Lower SAT attenuation, a measure of lipid content, was associated with lower visceral adipose tissue attenuation. Hierarchical clustering identified a subset of macrophage-related genes in SAT, including CCL2 , CCL22 , CCL13 , CCR1 , CD86 , CD163 , IL-6 , IL-10 , MRC1 , and TREM2 , which were associated with an increased lipid deposition in multiple ectopic depots. Conclusion: Altered expression of macrophage-related genes in SAT is associated with differences in ectopic fat depot morphometrics among PWH on long-term ART, including in the pericardial and visceral compartments. These findings provide basis for future studies to assess host, virus, and treatment factors shaping the SAT immune environment and its effects on morphometric changes and metabolic comorbidities in PWH. [ABSTRACT FROM AUTHOR]

Secretory polymorphic serine/threonine kinases control pathogenesis of Toxoplasma gondii in the mouse. Genetic studies show that the pseudokinase ROP5 is essential for acute virulence, but do not reveal its mechanism of action. Here we demonstrate that ROP5 controls virulence by blocking IFN-γ mediated clearance in activated macrophages. ROP5 was required for the catalytic activity of the active S/T kinase ROP18, which phosphorylates host immunity related GTPases (IRGs) and protects the parasite from clearance. ROP5 directly regulated activity of ROP18 in vitro, and both proteins were necessary to avoid IRG recruitment and clearance in macrophages. Clearance of both the Δrop5 and Δrop18 mutants was reversed in macrophages lacking Irgm3, which is required for IRG function, and the virulence defect was fully restored in Irgm3-/- mice. Our findings establish that the pseudokinase ROP5 controls the activity of ROP18, thereby blocking IRG mediated clearance in macrophages. Additionally, ROP5 has other functions that are also Irgm3 and IFN-γ dependent, indicting it plays a general role in governing virulence factors that block immunity. [ABSTRACT FROM AUTHOR]

The AP1 transcription factor Batf3 is required for homeostatic development of CD8?+ classical dendritic cells that prime CD8 T-cell responses against intracellular pathogens. Here we identify an alternative, Batf3-independent pathway in mice for CD8?+ dendritic cell development operating during infection with intracellular pathogens and mediated by the cytokines interleukin (IL)-12 and interferon-?. This alternative pathway results from molecular compensation for Batf3 provided by the related AP1 factors Batf, which also functions in T and B cells, and Batf2 induced by cytokines in response to infection. Reciprocally, physiological compensation between Batf and Batf3 also occurs in T cells for expression of IL-10 and CTLA4. Compensation among BATF factors is based on the shared capacity of their leucine zipper domains to interact with non-AP1 factors such as IRF4 and IRF8 to mediate cooperative gene activation. Conceivably, manipulating this alternative pathway of dendritic cell development could be of value in augmenting immune responses to vaccines. [ABSTRACT FROM AUTHOR]

Commitment of hematopoietic progenitors to the T cell lineage requires the integration of multiple signaling pathways. Evidence has suggested involvement of hedgehog (Hh) signaling in T cell differentiation through its signal transducer smoothened (Smo). However, the precise function of the Hh pathway remains controversial, mainly because T cell–specific in vivo genetic models have not been used. Using pre–T cell–specific, mature T cell–specific and poly(I)·poly(C)-inducible deletions of Smo and antagonists of Smo signaling, we report here that Hh is an essential positive regulator of T cell progenitor differentiation. Furthermore, we localize Hh function to a stage preceding pre–T cell receptor signaling, connect Smo signaling to the activity of the Gli1 and Gli2 transcription factors and demonstrate that Hh affects regulators of thymocyte survival and proliferation. [ABSTRACT FROM AUTHOR]