Preliminary analysis of immune activation in early onset type 2 diabetes

Gene Expression Profiling of Peripheral Blood Mononuclear Cells in Type 2 Diabetes: An Exploratory Study

Background and Objectives: Visceral obesity is associated with chronic low-grade inflammation that predisposes to metabolic syndrome. Indeed, infiltration of adipose tissue with immune-inflammatory cells, including 'classical' inflammatory M1 and anti-inflammatory 'alternative' M2 macrophages, causes the release of a variety of bioactive molecules, resulting in the metabolic complications of obesity. This study examined the relative expression of macrophage phenotypic surface markers, cholesterol efflux proteins, scavenger receptors, and adenosine receptors in human circulating peripheral blood mononuclear cells (PBMCs), isolated from patients with type 2 diabetes mellitus (T2DM), with the aim to phenotypically characterize and identify biomarkers for these ill-defined cells. Materials and Methodology: PBMCs were isolated from four groups of adults: Normal-weight non-diabetic, obese non-diabetic, newly diagnosed with T2DM, and T2DM on metformin. The mRNA expression levels of macrophage phenotypic surface markers (interleukin-12 (IL-12), C-X-C motif chemokine ligand 10 (CXCL10), C-C motif chemokine ligand 17 (CCL17), and C-C motif receptor 7 (CCR7)), cholesterol efflux proteins (ATP-binding cassette transporter-1 (ABCA1), ATP binding cassette subfamily G member 1 (ABCG1), and sterol 27-hydroxylase (CYP27A)), scavenger receptors (scavenger receptor-A (SR-A), C-X-C motif ligand 16 (CXCL16), and lectin-like oxidized LDL receptor-1 (LOX-1)), and adenosine receptors (adenosine A2A receptor (A2AR) and adenosine A3 receptor (A3R)) were measured using qRT-PCR. Results: In PBMCs from T2DM patients, the expression of IL-12, CCR7, ABCA1, and SR-A1 was increased, whereas the expression of CXCL10, CCL17, ABCG1,27-hydroxylase, LOX-1, A2AR and A3R was decreased. On the other hand, treatment with the antidiabetic drug, metformin, reduced the expression of IL-12 and increased the expression of 27-hydroxylase, LOX-1, CXCL16 and A2AR. Conclusions: PBMCs in the circulation of patients with T2DM express phenotypic markers that are different from those typically present in adipose tissue M1 and M2 macrophages and could be representative of metabolically activated macrophages (MMe)-like cells. Our findings suggest that metformin alters phenotypic markers of MMe-like cells in circulation.

Health consequences of early-onset compared with late-onset type 2 diabetes mellitus

Background

Although cumulating evidence has suggested that early-onset type 2 diabetes mellitus (T2DM) conferred on patients a broader tendency for complications beyond vascular ones, a comprehensive analysis of patterns of complications across all relevant systems is currently lacking.

Method

We prospectively studied 1 777 early-onset (age at diagnosis ≤ 45 years) and 35 889 late-onset (>45 years) T2DM patients with matched unexposed individuals from the UK Biobank. Diabetes-specific and -related complications were examined using phenome-wide association analysis, with patterns identified by comorbidity network analysis. We also evaluated the effect of lifestyle modifications and glycemic control on complication development.

Results

The median follow-up times for early-onset and late-onset T2DM patients were 17.83 and 9.39 years, respectively. Compared to late-onset T2DM patients, patients with early-onset T2DM faced a significantly higher relative risk of developing subsequent complications that primarily affected sense organs [hazard ratio (HR) 3.46 vs. 1.72], the endocrine/metabolic system (HR 3.08 vs. 2.01), and the neurological system (HR 2.70 vs. 1.81). Despite large similarities in comorbidity patterns, a more complex and well-connected network was observed for early-onset T2DM. Furthermore, while patients with early-onset T2DM got fewer benefits (12.67% reduction in pooled HR for all studied complications) through fair glycemic control (median HbA_1c ≤ 53 mmol/mol) compared to late-onset T2DM patients (18.01% reduction), they seemed to benefit more from favorable lifestyles, including weight control, healthy diet, and adequate physical activity.

Conclusions

Our analyses reveal that early-onset T2DM is an aggressive disease resulting in more complex complication networks than late-onset T2DM. Aggressive glucose-lowering intervention, complemented by lifestyle modifications, are feasible strategies for controlling early-onset T2DM-related complications.

Gingipain R1 and Lipopolysaccharide From Porphyromonas gingivalis Have Major Effects on Blood Clot Morphology and Mechanics

Background:Porphyromonas gingivalis and its inflammagens are associated with a number of systemic diseases, such as cardiovascular disease and type 2 diabetes (T2DM). The proteases, gingipains, have also recently been identified in the brains of Alzheimer's disease patients and in the blood of Parkinson's disease patients. Bacterial inflammagens, including lipopolysaccharides (LPSs) and various proteases in circulation, may drive systemic inflammation.

Methods: Here, we investigate the effects of the bacterial products LPS from Escherichia coli and Porphyromonas gingivalis, and also the P. gingivalis gingipain [recombinant P. gingivalis gingipain R1 (RgpA)], on clot architecture and clot formation in whole blood and plasma from healthy individuals, as well as in purified fibrinogen models. Structural analysis of clots was performed using confocal microscopy, scanning electron microscopy, and AFM-Raman imaging. We use thromboelastography® (TEG®) and rheometry to compare the static and dynamic mechanical properties of clots.

Results: We found that these inflammagens may interact with fibrin(ogen) and this interaction causes anomalous blood clotting.

Conclusions: These techniques, in combination, provide insight into the effects of these bacterial products on cardiovascular health, and particularly clot structure and mechanics.

Inflammatory markers in children and adolescents with type 2 diabetes mellitus

This review examines the potential relationship between serum inflammation markers and type 2 diabetes mellitus (T2DM). Inflammation markers have been proposed as prognostic markers for the development of T2DM and its complications. Furthermore, modulation of the inflammatory process may offer future treatment strategies for T2DM. This review focuses on children and adolescents because there is usually little, if any, complications associated with other disease processes, use of medications, or active tobacco smoking. Furthermore, β-cell failure in young age cannot be solely explained by aging and exhaustion of β-cells due to insulin resistance. Pediatric studies have demonstrated that pro-inflammatory cytokines TNF-α, IL-6, IL-1β, IFNγ, PEDF, and fetuin A were increased in insulin resistance, while the anti-inflammatory cytokines adiponectin and omentin were decreased. Furthermore, TNF-α, fetuin A, FGF-21 were altered in obese children with T2DM suggesting a direct involvement in β-cell failure. Future studies focusing on children and adolescents may facilitate our understanding of T2DM as an inflammatory disease process.

The Influence of Hepatitis C Viral Loads on Natural Killer Cell Function

Background

Hepatitis C virus (HCV) infection has a high rate of chronicity, attributable to its capacity to alter host immunity, including natural killer (NK) cell function. In this study, the interaction between NK cell activity and HCV viral load was investigated.

Methods

Peripheral blood NK cells were examined for cytotoxicity and interferon (IFN)-γ expression in HCV infected low (LVL, < 800,000 IU/mL, n = 10) and high (HVL, > 800,000 IU/mL, n = 13) viral load patient cohorts.

Results

Spontaneous NK cell cytotoxicity was more robust in the LVL cohort resulting in a negative correlation with viral loads (spontaneous, r = -0.437, P = 0.037; IFN-α activated, r = -0.372, P = 0.081). Although the percent of IFN-γ+ NK cells did not associate with viral load, within the LVL cohort there was a marked increase in IFN-γ+ NK cells upon IFN-α activation relative to medium alone (P < 0.01). To examine the inability of NK cells derived from HVL patients to be further activated, the expression of the exhaustion marker programmed cell death protein (PD)-1 was evaluated. PD-1 expression upon NK cell activation correlated with viral load (r = 0.649, P = 0.009). In addition, HCV proteins upregulated PD-1 expression in vitro (P < 0.05), suggesting that HCV can directly promote NK cell exhaustion. Cells from HVL patients were also more likely to produce IFN-γ in response to HCV core protein. The finding that NK cell PD-1 and IFN-γ expression are linked (r = 0.542, P < 0.05) suggests that increased IFN-γ levels may induce PD-1 as a negative feedback mechanism.

Conclusions

High HCV loads appear to promote NK exhaustion in chronic HCV infection.

Can the Toll-like receptors 4 expression in peripheral blood mononuclear cells help assess the effectiveness of immunosuppression and the chance of a future good renal transplant function?

BACKGROUND

A small percentage of peripheral blood mononuclear cells (PBMCs) circulating during the kidney transplantation (KT) period remain in the blood long after transplantation. A part of the PBMCs penetrates the graft.

AIM

To examine if the choice of immunosuppression may change TLR4ex and how TLR4ex affects the transplant function in the future.

MATERIAL

The study population-143 transplanted patients (pts) (55 females, 88 males), mean age on recruitment day 50.33 ± 12.8 years old, mean BMI 25.04 ± 4.18. 41 pts. experienced delayed graft function (DGF+). 55 pts. were treated with cyclosporine A (CsA) and 88 with tacrolimus (Tac). All were treated with mofetil mycophenolate (MMF). The PBMCs acquisition and starting point of the follow-up (TLR-day) was at least one month after KT.

METHOD

We investigated averaged mRNA expression of Toll-like receptors 4 (TLR4ex) in non-stimulated peripheral blood mononuclear cells with the use of real-time polymerase chain reaction. The KT pts. (All, Tac, CsA, DGF+) were divided by the respective median of their TLR4ex (lower: L-TLR4ex, higher: H-TLR4ex). Main clinical parameters and transplant biopsy files (if available) were assessed on TLR-day and post follow-up.

RESULTS

We found that TLR4ex was reduced for a long time in patients who experienced delayed graft function. L-TLR4ex had a higher proportion of DGF+ patients, and patients treated with CsA but lower of those treated with Tac than in H-TLR4ex. The amplitude of changes in renal function parameters (ΔEGFR%/ΔsCr/ΔsCr%) was clearly less favorable for L-TLR4ex. Tacrolimus expressed a stabilizing effect. Both the positive vasculitis score and chronic graft nephropathy were more frequent in the L-TLR4ex group. On TLR-day an association of renal function and Tac concentration with TLR4ex was clear only in the tacrolimus population. The TLR4ex was lower in patients with a future deterioration of the graft function.

CONCLUSION

In kidney transplant recipients the occurrence of DGF results in a long-term reduction of the averaged TLR4ex in PBMC. Tacrolimus exerts a clear, stabilizing, positive and dose-dependent effect on TLR4ex. An improvement in renal transplant function may be expected in KT patients with high TLR4ex. Evaluation of the averaged TLR4ex can be used to assess the efficacy of immunosuppression in the treatment with tacrolimus and to estimate the likelihood of deterioration in renal function.

Inflammation Markers in Type 2 Diabetes and the Metabolic Syndrome in the Pediatric Population

PURPOSE OF REVIEW

Chronic inflammation, adipokines, and hepatokines have been identified as basis of insulin resistance and β cell failure in animal models. We present our current knowledge concerning the potential relationship between these cytokines, inflammation, metabolic syndrome (MetS), and type 2 diabetes mellitus (T2DM) in the pediatric population.

RECENT FINDINGS

Pro-inflammatory cytokines related to insulin resistance and MetS in children are tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-1β, interferon gamma, pigment epithelium-derived factor, chemerin, vaspin, and fetuin A. Anti-inflammatory cytokines associated with insulin resistance and MetS in children are leptin, adiponectin, omentin, fibroblast growth factor (FGF)-21, osteocalcin, and irisin. These anti-inflammatory cytokines are decreased (adiponectin, omentin, and osteocalcin) or increased (leptin, FGF-21, and irisin) in obesity suggesting a resistance state. TNF-α, fetuin A, and FGF-21 are altered in obese children with T2DM suggesting an involvement in β cell failure. These cytokines, adipokines, and hepatokines may be able to predict development of MetS and T2DM and have a potential therapeutic target ameliorating insulin resistance.

Gut Microbiome in Obesity, Metabolic Syndrome, and Diabetes

PURPOSE OF REVIEW

Obesity and diabetes are worldwide epidemics. There is also a growing body of evidence relating the gut microbiome composition to insulin resistance. The purpose of this review is to delineate the studies linking gut microbiota to obesity, metabolic syndrome, and diabetes.

RECENT FINDINGS

Animal studies as well as proof of concept studies using fecal transplantation demonstrate the pivotal role of the gut microbiota in regulating insulin resistance states and inflammation. While we still need to standardize methodologies to study the microbiome, there is an abundance of evidence pointing to the link between gut microbiome, inflammation, and insulin resistance, and future studies should be aimed at identifying unifying mechanisms.

Association between IL-15 and insulin plasmatic concentrations in patients with pulmonary tuberculosis and type 2 diabetes

IL-15 is part of the immune response in pulmonary tuberculosis (PTB) but amazingly, it may also induce physiological effects similar to those of insulin. We evaluated the IL-15 and insulin plasmatic levels in adults with PTB and with or without type 2 diabetes mellitus (DM2), who received previous antituberculosis therapy for at least 2 months. We analyzed the concentrations of glucose, glycated hemoglobin, insulin, as well as levels of IL-15, IL-2, IFN-γ, and TNF-α in patients with PTB, patients with PTB-DM2, household contacts with DM2 (C-DM2), and healthy household contacts (H-C). Our results showed unexpected high levels of glucose, insulin, and IL-15 in the PTB and C-DM2 groups. In comparison, low levels of these same indicators were observed in the PTB-DM2 and H-C groups. Interestingly, our analysis showed a positive correlation of IL-15 with insulin in the PTB group (r = 0.73) and in the C-DM2 group (r = 0.66). In comparison, a weak correlation between IL-15 and insulin was observed in the PTB-DM group (r = 0.10) and in the H-C group (ρ = 0.26). Our results suggest an association between IL-15 and insulin levels in the patient with PTB. Intriguingly, this association was weaker in the patient with PTB-DM2.

The metabolites in peripheral blood mononuclear cells showed greater differences between patients with impaired fasting glucose or type 2 diabetes and healthy controls than those in plasma

To determine differences between peripheral blood mononuclear cells and the plasma metabolites in patients with impaired fasting glucose or type 2 diabetes and healthy controls. In all, 65 nononobese patients (aged 30-70 years) with impaired fasting glucose or type 2 diabetes and 65 nonobese sex-matched healthy controls were included, and fasting peripheral blood mononuclear cell and plasma metabolomes were profiled. The diabetic or impaired fasting glucose patients showed higher circulating and peripheral blood mononuclear cell lipoprotein phospholipase A₂ activities, high-sensitivity C-reactive protein and tumour necrosis factor-α than controls. Compared with controls, impaired fasting glucose or diabetic subjects showed increases in 11 peripheral blood mononuclear cell metabolites: six amino acids (valine, leucine, methionine, phenylalanine, tyrosine and tryptophan), l-pyroglutamic acid, two fatty acid amides containing palmitic amide and oleamide and two lysophosphatidylcholines. In impaired fasting glucose or diabetic patients, peripheral blood mononuclear cell lipoprotein phospholipase A₂ positively associated with peripheral blood mononuclear cell lysophosphatidylcholines and circulating inflammatory markers, including tumour necrosis factor-α, high-sensitivity C-reactive protein and lipoprotein phospholipase A₂ activities. In plasma metabolites between patients and healthy controls, we observed significant increases in only three amino acids (proline, valine and leucine) and decreases in only five lysophosphatidylcholines. This study demonstrates significant differences in the peripheral blood mononuclear cell metabolome in patients with impaired fasting glucose or diabetes compared with healthy controls. These differences were greater than those observed in the plasma metabolome. These data suggest peripheral blood mononuclear cells as a useful tool to better understand the inflammatory pathophysiology of diabetes.

Caloric restriction ameliorates cardiomyopathy in animal model of diabetes

BACKGROUND

The db/db mouse is an animal model of diabetes in which leptin receptor activity is deficient resulting accelerated cardiomyopathy when exposed to angiotensin (AT). Toll-like receptors 4 and 2 (TLR4, TLR2) are pattern recognition receptors, that recognize pathogen-associated molecular patterns and exacerbate and release inflammatory cytokines. Fetuin A (Fet A) is a fatty acid carrier which affects inflammation and insulin resistance in obese humans and animals through TLRs. The aim of this study was to investigate the effect of caloric restriction (CR) on free fatty acids (FFA) level and the inflammatory response in diabetic cardiomyopathy.

METHODS AND RESULTS

Left ventricular hypertrophy, increased fibrosis and leukocytes infiltration were observed in db/db AT treated hearts. Serum glucose, FFA, and cholesterol levels were elevated in db/db AT treated mice. Cardiac expression of PPARα increased while AKT phosphorylation was decreased.

CONCLUSIONS

Cumulatively, CR elevated cardiac PPARα improved the utilization of fatty acids, and reduced myocardial inflammation as seen by reduced levels of Fet A. Thus CR negated cardiomyopathy associated with AT in an animal model of diabetes suggesting that CR is an effective therapeutic approach in the treatment of diabetes and associated cardiomyopathy.

On the translocation of bacteria and their lipopolysaccharides between blood and peripheral locations in chronic, inflammatory diseases: the central roles of LPS and LPS-induced cell death

We have recently highlighted (and added to) the considerable evidence that blood can contain dormant bacteria. By definition, such bacteria may be resuscitated (and thus proliferate). This may occur under conditions that lead to or exacerbate chronic, inflammatory diseases that are normally considered to lack a microbial component. Bacterial cell wall components, such as the endotoxin lipopolysaccharide (LPS) of Gram-negative strains, are well known as potent inflammatory agents, but should normally be cleared. Thus, their continuing production and replenishment from dormant bacterial reservoirs provides an easy explanation for the continuing, low-grade inflammation (and inflammatory cytokine production) that is characteristic of many such diseases. Although experimental conditions and determinants have varied considerably between investigators, we summarise the evidence that in a great many circumstances LPS can play a central role in all of these processes, including in particular cell death processes that permit translocation between the gut, blood and other tissues. Such localised cell death processes might also contribute strongly to the specific diseases of interest. The bacterial requirement for free iron explains the strong co-existence in these diseases of iron dysregulation, LPS production, and inflammation. Overall this analysis provides an integrative picture, with significant predictive power, that is able to link these processes via the centrality of a dormant blood microbiome that can resuscitate and shed cell wall components.

Leptin but not adiponectin is related to type 2 diabetes mellitus in obese adolescents

BACKGROUND

Adipokines have been suggested to be involved in the development of type 2 diabetes mellitus (T2DM). However, studies in humans are controversial and analyzes at the onset of disease are scarce.

METHODS

We compared adiponectin and leptin levels between 74 predominately Caucasian adolescents with T2DM and 74 body mass index (BMI)-, age-, and gender-matched controls without T2DM. Adiponectin and leptin were correlated to age, BMI, hemoglobin A1c (HbA1c), blood pressure, and lipids.

RESULTS

Adolescents with T2DM showed significant lower leptin levels as compared with controls (18 ± 12 vs. 37 ± 23 ng/mL, p < 0.001), whereas the adiponectin levels did not differ between the adolescents with and without T2DM (5.0 ± 2.5 vs. 4.9 ± 2.5 µg/mL, p = 0.833). The associations between adiponectin and high-density lipoprotein (HDL) cholesterol (r = 0.42), systolic (r = -0.15), and diastolic blood pressure (r = -0.20) were stronger as the associations of leptin to these parameters (all r < 0.07). In multiple linear regression analysis, leptin was significantly and positively associated with BMI [β-coefficient: 1.3 (95% confidence interval (95% CI): ±0.5), p < 0.001] and female sex [β-coefficient: 9.7 (95% CI: ±6.7), p = 0.005], and negatively with age [β-coefficient: -2.3 (95% CI: ±2.1), p < 0.001] and HbA1c [β-coefficient -3.1 (95% CI: ±2.1), p = 0.011]. Adiponectin was not significantly associated with BMI, HbA1c, age, or gender in multiple linear regression analysis.

CONCLUSIONS

Because adiponectin levels did not differ between obese adolescents with and without T2DM, hypoadiponectinemia as observed in obesity seems not to be involved in the genesis of T2DM. The relative hypoleptinemia in obese adolescents with T2DM as compared with obese adolescents without T2DM may contribute to the development of T2DM. Future longitudinal studies in humans are necessary to prove this hypothesis.