NLRP3 Inflammasome Polymorphism and Macrovascular Complications in Type 2 Diabetes Patients

From Innate Immunity to Metabolic Disorder: A Review of the NLRP3 Inflammasome in Diabetes Mellitus

The role of the NLRP3 inflammasome is pivotal in the pathophysiology and progression of diabetes mellitus (DM), encompassing both type 1 (T1D), or type 2 (T2D). As part of the innate immune system, NLRP3 is also responsible for the chronic inflammation triggered by hyperglycemia. In both conditions, NLRP3 facilitates the release of interleukin-1β and interleukin-18. For T1D, NLRP3 perpetuates the autoimmune cascade, leading to the destruction of pancreatic islet cells. In T2D, its activation is associated with the presence of insulin resistance. NLRP3 activation is also instrumental for the presence of numerous complications associated with DM, microvascular and macrovascular. A considerable number of anti-diabetic drugs have demonstrated the ability to inhibit the NLRP3 inflammasome.

Prevalence of prediabetes, diabetes, diabetes awareness, treatment, and its socioeconomic inequality in west of Iran

We aim to estimate the prevalence of prediabetes, and diabetes mellitus (DM). We estimated awareness, treatment, plasma glucose control, and associated factors in diabetes, as well as, socioeconomic-related inequality in the prevalence of diabetes and prediabetes. Data for adults aged 35-70 years were obtained from the baseline phase of the Dehgolan prospective cohort study (DehPCS). Diabetes status was determined as fasting plasma glucose (FPG) of ≥ 126 mg/dl and/or taking glucose lowering medication confirmed by a medical practitioner. Prediabetes was considered as 100 ≤ FPG ≤ 125 mg/dl. The relative concentration index (RCI) was used to exhibit socioeconomic inequality in the prevalence of prediabetes and DM. Prevalence of prediabetes and DM, diabetes awareness and treatment, and glycemic control of DM 18.22%, 10.00%, 78.50%, 68.91% and, 28.50%, respectively. Increasing age (p < 0.001), Increasing body mass index (BMI) (p < 0.05), ex-smoker (p < 0.01), family history of diabetes (FHD) (p < 0.001), and comorbidity (p < 0.001) were independent risk factors for DM. Age group of 46-60 (p < 0.05), ex-smoker (p < 0.05), FHD (p < 0.05) were increased chance of awareness. Current smokers (p < 0.05), and higher education increase the chance of glycemic control in DM. Both DM (RCI =  - 0.234) and prediabetes (RCI =  - 0.122) were concentrated significantly among less-educated participants. DM was concentrated significantly among poor (RCI =  - 0.094) people. A significant proportion of DM awareness and treatment can be due to the integration of diabetes into the primary health care system. The high prevalence of prediabetes and diabetes, which is affected by socioeconomic inequality and combined with low levels of glycemic control may place a greater burden on the health system. Therefore, awareness, receiving treatment, and glycemic control in people with diabetes, and the socioeconomic status of people have become increasingly important in the near future.

The combined effects of nucleotide-binding domain-like receptor protein 3 polymorphisms and levels of blood lead on developmental delays in preschool children

Nucleotide-binding domain-like receptors protein 3 (NLRP3) inflammasomes are associated with neuroinflammation and multiple NLRP3 genes regulate NLRP3 expression. Our study aimed to investigate the association of NLRP3 polymorphisms with developmental delay in preschool children. We also explored whether NLRP3 polymorphisms modified the effects of total urinary arsenic and blood cadmium and lead to developmental delays. A total of 178 children with developmental delays and 88 healthy children were analyzed for urinary arsenic concentrations and red blood cell lead and cadmium concentrations. We examined the genotypes of fifteen common single-nucleotide polymorphisms in NLRP3. We observed that levels of total urinary arsenic and blood lead were significantly associated with developmental delay. The NLRP3rs10754555 CG versus CC/GG, NLRP3rs12048215 AG versus AA/GG, and NLRP3rs12137901 TC/TT versus CC genotype showed a lower odds of developmental delay, with the odds ratio (OR) and 95% confidence interval (CI) = 0.38 (0.19-0.75), 0.52 (0.27-0.99), and 0.33 (0.12-0.90), respectively. Children with the NLRP3rs10754555 CC/GG genotype and high blood lead levels had a significant multiplicative interaction with developmental delay [OR (95% CI) = 9.74 (3.59-26.45)]. This study found evidence that suggested the joint effects of NLRP3rs10754555 CC/GG genotype and high blood lead levels on developmental delays.

Inflammation as A Precursor of Atherothrombosis, Diabetes and Early Vascular Aging

Vascular disease was for a long time considered a disease of the old age, but it is becoming increasingly clear that a cumulus of factors can cause early vascular aging (EVA). Inflammation plays a key role in vascular stiffening and also in other pathologies that induce vascular damage. There is a known and confirmed connection between inflammation and atherosclerosis. However, it has taken a long time to prove the beneficial effects of anti-inflammatory drugs on cardiovascular events. Diabetes can be both a product of inflammation and a cofactor implicated in the progression of vascular disease. When diabetes and inflammation are accompanied by obesity, this ominous trifecta leads to an increased incidence of atherothrombotic events. Research into earlier stages of vascular disease, and documentation of vulnerability to premature vascular disease, might be the key to success in preventing clinical events. Modulation of inflammation, combined with strict control of classical cardiovascular risk factors, seems to be the winning recipe. Identification of population subsets with a successful vascular aging (supernormal vascular aging-SUPERNOVA) pattern could also bring forth novel therapeutic interventions.

Periodontitis activates the NLRP3 inflammasome in serum and saliva

BACKGROUND

Nod-like receptor family pyrin domain-containing protein-3 (NLRP3) complex inflammasome has potentially been shown to play an important role in the development of periodontitis and diabetes. The objective of this study was to analyze the association between serum and salivary NLRP3 concentrations in patients with periodontitis and type-II diabetes mellitus (DM) and to evaluate whether this association was influenced by potential confounders.

METHODS

For the present study, a cohort of healthy controls (n = 32), and patients with periodontitis (n = 34), type-II DM (n = 33), and a combination of periodontitis + type-II DM (n = 34) were enrolled. Patients were characterized on the basis of their periodontal status and analyzed for demographic characteristics, serum mediators, and for serum and salivary concentrations of NLRP3. A uni- and multivariate model was established to analyze whether periodontitis, type-II DM, and CRP influenced serum and salivary NLRP3 concentrations.

RESULTS

In comparison to type-II DM patients and healthy controls, patients with periodontitis (serum, P = 0.003; saliva P = 0.012) and periodontitis + type-II DM (serum, P = 0.028; saliva, P = 0.003) had elevated serum and salivary NLRP3 concentrations. The multivariate regression model showed that periodontitis (P = 0.029) and HDL-cholesterol (P = 0.012) were significant predictors of serum NLRP3 concentrations whereas periodontitis (P = 0.036) and CRP (P = 0.012) were significant predictors of salivary NLRP3.

CONCLUSION

The results of the present study showed that periodontitis and periodontitis + type-II DM patients had higher serum and salivary NLRP3 concentrations in comparison to healthy controls and patients with type-II DM. Periodontitis was demonstrated to be a significant predictor of both serum and salivary NLRP3 concentrations.

Phytochemical inhibitors of the NLRP3 inflammasome for the treatment of inflammatory diseases

The NLRP3 inflammasome holds a crucial role in innate immune responses. Pathogen- and danger-associated molecular patterns may initiate inflammasome activation and following inflammatory cytokine release. The inflammasome formation and its-associated activity are involved in various pathological conditions such as cardiovascular, central nervous system, metabolic, renal, inflammatory and autoimmune diseases. Although the mechanism behind NLRP3-mediated disorders have not been entirely illuminated, many phytochemicals and medicinal plants have been described to prevent inflammatory disorders. In the present review, we mainly introduced phytochemicals inhibiting NLRP3 inflammasome in addition to NLRP3-mediated diseases. For this purpose, we performed a systematic literature search by screening PubMed, Scopus, and Google Scholar databases. By compiling the data of phytochemical inhibitors targeting NLRP3 inflammasome activation, a complex balance between inflammasome activation or inhibition with NLRP3 as central player was pointed out in NLRP3-driven pathological conditions. Phytochemicals represent potential therapeutic leads, enabling the generation of chemical derivatives with improved pharmacological features to treat NLRP3-mediated inflammatory diseases.

NLRP3 inflammasome in cardiovascular diseases: Pathophysiological and pharmacological implications

Growing evidence points out the importance of nucleotide-binding oligomerization domain leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) inflammasome in the pathogenesis of cardiovascular diseases (CVDs), including hypertension, myocardial infarct (MI), ischemia, cardiomyopathies (CMs), heart failure (HF), and atherosclerosis. In this regard, intensive research efforts both in humans and in animal models of CVDs are being focused on the characterization of the pathophysiological role of NLRP3 inflammasome signaling in CVDs. In addition, clinical and preclinical evidence is coming to light that the pharmacological blockade of NLRP3 pathways with drugs, including novel chemical entities as well as drugs currently employed in the clinical practice, biologics and phytochemicals, could represent a suitable therapeutic approach for prevention and management of CVDs. On these bases, the present review article provides a comprehensive overview of clinical and preclinical studies about the role of NLRP3 inflammasome in the pathophysiology of CVDs, including hypertension, MI, ischemic injury, CMs, HF and atherosclerosis. In addition, particular attention has been focused on current evidence on the effects of drugs, biologics, and phytochemicals, targeting different steps of inflammasome signaling, in CVDs.

CARD8 and IL1B Polymorphisms Influence MRI Brain Patterns in Newborns with Hypoxic-Ischemic Encephalopathy Treated with Hypothermia

Inflammation and oxidative stress are recognized as important contributors of brain injury in newborns due to a perinatal hypoxic-ischemic (HI) insult. Genetic variability in these pathways could influence the response to HI and the outcome of brain injury. The aim of our study was to evaluate the impact of common single-nucleotide polymorphisms in the genes involved in inflammation and response to oxidative stress on brain injury in newborns after perinatal HI insult based on the severity and pattern of magnetic resonance imaging (MRI) findings. The DNA of 44 subjects was isolated from buccal swabs. Genotyping was performed for NLRP3 rs35829419, CARD8 rs2043211, IL1B rs16944, IL1B rs1143623, IL1B rs1071676, TNF rs1800629, CAT rs1001179, SOD2 rs4880, and GPX1 rs1050450. Polymorphism in CARD8 was found to be protective against HI brain injury detected by MRI overall findings. Polymorphisms in IL1B were associated with posterior limb of internal capsule, basal ganglia, and white matter brain patterns determined by MRI. Our results suggest a possible association between genetic variability in inflammation- and antioxidant-related pathways and the severity of brain injury after HI insult in newborns.

NLRP3 and NLRP1 inflammasomes are up-regulated in patients with mesial temporal lobe epilepsy and may contribute to overexpression of caspase-1 and IL-β in sclerotic hippocampi

Inflammation plays a role in the pathophysiology of mesial temporal lobe epilepsy (MTLE). Inflammasome pathways, including the NLRP1 and NLRP3-induced ones, promote neuroinflammation and pyroptosis through interleukin (IL)-1β and caspase-1 action. Evaluation of NLRP1 in sclerotic hippocampi is scarce and there are no data on NLRP3 in human TLE. The aim of this study was to evaluate the expression of these proteins alongside caspase-1 and IL-1β in the hippocampi of patients with TLE compared to control samples. We also sought to investigate peripheral levels of caspase-1 and IL-1β in an independent cohort. Sclerotic and control hippocampi were collected for both histological and immunohistochemical analyses of NLRP1, NLRP3, caspase-1 and IL-1β; plasma was sampled for the measurement of caspase-1 and IL-1β levels through enzyme-linked immunoassay (ELISA) and cytometric bead array (CBA). Sclerotic hippocampi displayed higher expression of the measured proteins than control. Both glia and neurons showed activation of these pathways. Additionally, increased expression of NLRP1 and NLRP3 was associated with elevated plasma levels of IL-1β and in TLE, and increased levels of peripheral caspase-1 were associated with bilateral hippocampal sclerosis (HS). In conclusion, NLRP1 and NLRP3 are up-regulated in sclerotic hippocampi, what may be responsible, at least in part, for the increased hippocampal expression of caspase-1 and IL-1β. Our data suggest a role for inflammasome activation in central and peripheral inflammation in TLE.

Identification of NLRP3 Inflammation-Related Gene Promoter Hypomethylation in Diabetic Retinopathy

Purpose

To identify and validate key genes that could provide a new perspective for genetic marker screening of diabetic retinopathy (DR).

Methods

The gene expression and DNA methylation profiles were obtained from the Gene Expression Omnibus. Differential expression analysis was conducted using the limma package, and then the functions of the differentially expressed genes (DEGs) were analyzed using the DAVID database, followed by protein–protein interaction (PPI) networks using Cytoscape software. We employed the Sequenom MassARRAY system to detect the promoter methylation levels of the candidate genes in peripheral blood mononuclear cells from 32 healthy individuals and 94 patients with type 2 diabetes mellitus (T2D; 64 with DR and 30 without DR) and in fibrovascular membranes (FVMs) from three proliferative DR patients and three controls with idiopathic epiretinal membranes. The mRNA levels of candidate genes were further confirmed via real-time polymerase chain reaction.

Results

A significant enrichment of 5906 DEGs was found in immune and inflammatory responses. TGFB1, CCL2, and TNFSF2 were identified as the top three core genes associated with NLRP3 inflammation in PPI networks. These genes have relatively low levels of promoter methylation, which have been validated in peripheral blood mononuclear cells and FVMs from DR patients, and the methylation levels were found to be negative correlated with the mRNA levels and HbA1c levels in T2D patients.

Conclusions

Overall, these data indicate that promoter hypomethylation of NLRP3, TGFB1, CCL2, and TNFSF2 may increase the risk of DR in the Chinese Han population, indicating that these genes might serve as potential targets for the detection and treatment of DR.

Genetic variation in CARD8, a gene coding for an NLRP3 inflammasome-associated protein, alters the genetic risk for diabetic nephropathy in the context of type 2 diabetes mellitus

BACKGROUND

Approximately one third of type 2 diabetes mellitus (T2DM) cases present with diabetic nephropathy (DN), the leading cause of end-stage renal disease. Inflammation plays an important role in T2DM disease and DN pathogenesis. NLRP3 inflammasomes are complexes that regulate interleukin-1B (IL-1B) and IL-18 secretion, both involved in inflammatory responses. Activation of NLRP3 is associated with DN onset and progression. Here, we explore whether DN is associated with variants in genes encoding key members of the NLRP3 inflammasome pathway.

METHODS

Using genome-wide association data, we performed a pilot case-control association study, between 101 DN-T2DM and 185 non-DN-T2DM cases from the Hellenic population across six NLRP3 inflammasome pathway genes.

RESULTS

Three common CARD8 variants confer decreased risk for DN, namely rs11665831 (OR = 0.62, p = 0.016), rs11083925 (OR = 0.65, p = 0.021), and rs2043211 (OR = 0.66, p = 0.026), independent of sex or co-inheritance with an IL-1B variant.

CONCLUSION

CARD8 acts as an NLRP3, NF-κB and caspase-1 inhibitor; perhaps, alterations in the cross-talk between CARD8, NF-κB, and NLRP3, which could affect the pro-inflammatory environment in T2DM, render diabetic carriers of certain common CARD8 variants potentially less likely to develop T2DM-related pro-inflammatory responses followed by DN. These preliminary, yet novel, observations will require validation in larger cohorts from several ethnic groups.

Genetic Variability in Antioxidative and Inflammatory Pathways Modifies the Risk for PCOS and Influences Metabolic Profile of the Syndrome

Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder of multifactorial etiopathology likely to involve the interactions between genetics and lifestyle. Chronic inflammation and oxidative stress (OS) may participate in the pathophysiology of the syndrome. The question of the extent to which OS and inflammation are causally related to the development of the syndrome and metabolic complications remains unanswered. By our knowledge, the role of the NLR family pyrin domain containing 3 (NLRP3) inflammasome as an important trigger of inflammatory pathways and NLRP3 and CARD8 polymorphisms has never been addressed in PCOS yet. We conducted a case-control study conducting of total 169 Slovenian PCOS patients and 83 healthy blood donors. They were genotyped for polymorphisms in antioxidative (SOD2 rs4880, CAT rs1001179, PON1 rs854560, and rs662) and inflammatory pathways genes (NLRP3 rs35829419, CARD8 rs2043211, TNF rs1800629, IL1B rs1143623, and rs16944, IL6 rs1800795) using competitive allele-specific polymerase chain reaction (PCR). Logistic regression and the Mann–Whitney test were used in the statistical analysis. SOD2 rs4880, CARD8 rs2043211, and IL1B rs16944 were associated with the risk of developing PCOS. Furthermore, the interactions between CARD8 rs2043211 and IL6 rs1800795 and between IL1B rs1143623 and IL6 rs1800795 also significantly affected the risk for PCOS. With regard to glucose homeostasis, CAT rs1001179, SOD2 rs4880, PON1 rs854560, NLRP3 rs35829419, and TNF rs1800629 were significantly associated with response to the glycemic load. Our data indicate that the genetic variability in the antioxidative and inflammatory pathways influences the development of PCOS and glucose homeostasis in PCOS patients.

Up-regulation of FoxO1 contributes to adverse vascular remodelling in type 1 diabetic rats

Vascular complications from diabetes often result in poor outcomes for patients, even after optimized interventions. Forkhead box protein O1 (FoxO1) is a key regulator of cellular metabolism and plays an important role in vessel formation and maturation. Alterations of FoxO1 occur in the cardiovascular system in diabetes, yet the role of FoxO1 in diabetic vascular complications is poorly understood. In Streptozotocin (STZ)‐induced type 1 diabetic rats, FoxO1 expression was up‐regulated in carotid arteries at 8 weeks of diabetes that was accompanied with adverse vascular remodelling characterized as increased wall thickness, carotid medial cross‐sectional area, media‐to‐lumen ratio and decreased carotid artery lumen area. This adverse vascular remodelling induced by hyperglycaemia in diabetic rats required FoxO1 activation as pharmacological inhibition of FoxO1 with 50mg/kg AS1842856 (AS) reversed vascular remodelling in type 1 diabetic rats. The adverse vascular remodelling in type 1 diabetes mellitus (T1DM) occurred concomitantly with increases in pro‐inflammatory factors, adhesion factors, apoptosis, NOD‐like receptor family protein‐3 inflammasome activation and the phenotypic switch of arterial smooth muscle cells, which were all reversed by AS. In addition, FoxO1 inhibition counteracted the down‐regulation of its upstream mediator PDK1 in T1DM. PDK1 activator reduced FoxO1 nuclear translocation, which serves as the basis for subsequent transcriptional regulation during hyperglycaemia. Taken together, our data suggest that FoxO1 is a critical trigger for type 1 diabetes‐induced vascular remodelling in rats, and inhibition of FoxO1 thus offers a potential therapeutic option for diabetes‐associated cardiovascular diseases.

Genetic variability in sodium-glucose cotransporter 2 influences glycemic control and risk for diabetic retinopathy in type 2 diabetes patients

BACKGROUND

Gluconeogenesis and renal glucose excretion in kidneys both play an important role in glucose homeostasis. Sodium-glucose cotransporter (SGLT2), coded by the SLC5A2 gene is responsible for reabsorption up to 99% of the filtered glucose in proximal tubules. SLC5A2 genetic polymorphisms were suggested to influence glucose homeostasis. We investigated if common SLC5A2 rs9934336 polymorphism influences glycemic control and risk for macro or microvascular complications in Slovenian type 2 diabetes (T2D) patients.

METHODS

All 181 clinically well characterized T2D patients were genotyped for SLC5A2 rs9934336 G>A polymorphism. Associations with glycemic control and T2D complications were assessed with nonparametric tests and logistic regression.

RESULTS

SLC5A2 rs9934336 was significantly associated with increased fasting blood glucose levels (P<0.001) and HbA1c levels under the dominant genetic model (P=0.030). After adjustment for T2D duration, significantly higher risk for diabetic retinopathy was present in carriers of at least one polymorphic SLC5A2 rs9934336 A allele compared to non-carriers (OR=7.62; 95%CI=1.65-35.28; P=0.009).

CONCLUSIONS

Our pilot study suggests an important role of SLC5A2 polymorphisms in the physiologic process of glucose reabsorption in kidneys in T2D patients. This is also the first report on the association between SLC5A2 polymorphism and diabetic retinopathy.

The Inflammasome in Chronic Complications of Diabetes and Related Metabolic Disorders

Diabetes mellitus (DM) ranks seventh as a cause of death worldwide. Chronic complications, including cardiovascular, renal, and eye disease, as well as DM-associated non-alcoholic fatty liver disease (NAFLD) account for most of the morbidity and premature mortality in DM. Despite continuous improvements in the management of late complications of DM, significant gaps remain. Therefore, searching for additional strategies to prevent these serious DM-related conditions is of the utmost importance. DM is characterized by a state of low-grade chronic inflammation, which is critical in the progression of complications. Recent clinical trials indicate that targeting the prototypic pro-inflammatory cytokine interleukin-1β (IL-1 β) improves the outcomes of cardiovascular disease, which is the first cause of death in DM patients. Together with IL-18, IL-1β is processed and secreted by the inflammasomes, a class of multiprotein complexes that coordinate inflammatory responses. Several DM-related metabolic factors, including reactive oxygen species, glyco/lipoxidation end products, and cholesterol crystals, have been involved in the pathogenesis of diabetic kidney disease, and diabetic retinopathy, and in the promoting effect of DM on the onset and progression of atherosclerosis and NAFLD. These metabolic factors are also well-established danger signals capable of regulating inflammasome activity. In addition to presenting the current state of knowledge, this review discusses how the mechanistic understanding of inflammasome regulation by metabolic danger signals may hopefully lead to novel therapeutic strategies targeting inflammation for a more effective treatment of diabetic complications.

Primary immunodeficiencies in cytosolic pattern-recognition receptor pathways: Toward host-directed treatment strategies

In the last decade, the paradigm of primary immunodeficiencies (PIDs) as rare recessive familial diseases that lead to broad, severe, and early-onset immunological defects has shifted toward collectively more common, but sporadic autosomal dominantly inherited isolated defects in the immune response. Patients with PIDs constitute a formidable area of research to study the genetics and the molecular mechanisms of complex immunological pathways. A significant subset of PIDs affect the innate immune response, which is a crucial initial host defense mechanism equipped with pattern-recognition receptors. These receptors recognize pathogen- and damage-associated molecular patterns in both the extracellular and intracellular space. In this review, we will focus on primary immunodeficiencies caused by genetic defects in cytosolic pattern-recognition receptor pathways. We discuss these PIDs organized according to their mutational mechanisms and consequences for the innate host response. The advanced understanding of these pathways obtained by the study of PIDs creates the opportunity for the development of new host-directed treatment strategies.

Multifactorial Activation of NLRP3 Inflammasome: Relevance for a Precision Approach to Atherosclerotic Cardiovascular Risk and Disease

Chronic low-grade inflammation, through the specific activation of the NACHT leucine-rich repeat- and PYD-containing (NLRP)3 inflammasome-interleukin (IL)-1β pathway, is an important contributor to the development of atherosclerotic cardiovascular disease (ASCVD), being triggered by intracellular cholesterol accumulation within cells. Within this pathological context, this complex pathway is activated by a number of factors, such as unhealthy nutrition, altered gut and oral microbiota, and elevated cholesterol itself. Moreover, evidence from autoinflammatory diseases, like psoriasis and others, which are also associated with higher cardiovascular disease (CVD) risk, suggests that variants of NLRP3 pathway-related genes (like NLRP3 itself, caspase recruitment domain-containing protein (CARD)8, caspase-1 and IL-1β) may carry gain-of-function mutations leading, in some individuals, to a constitutive pro-inflammatory pattern. Indeed, some reports have recently associated the presence of specific single nucleotide polymorphisms (SNPs) on such genes with greater ASCVD prevalence. Based on these observations, a potential effective strategy in this context may be the identification of carriers of these NLRP3-related SNPs, to generate a genomic score, potentially useful for a better CVD risk prediction, and, possibly, for personalized therapeutic approaches targeted to the NLRP3-IL-1β pathway.

Effect of Quamoclit angulata Extract Supplementation on Oxidative Stress and Inflammation on Hyperglycemia-Induced Renal Damage in Type 2 Diabetic Mice

Type 2 diabetes mellitus (T2DM) is caused by abnormalities of controlling blood glucose and insulin homeostasis. Especially, hyperglycemia causes hyper-inflammation through activation of NLRP3 inflammasome, which can lead to cell apoptosis, hypertrophy, and fibrosis. Quamoclit angulata (QA), one of the annual winders, has been shown ameliorative effects on diabetes. The current study investigated whether the QA extract (QAE) attenuated hyperglycemia-induced renal inflammation related to NLRP inflammasome and oxidative stress in high fat diet (HFD)-induced diabetic mice. After T2DM was induced, the mice were treated with QAE (5 or 10 mg/kg/day) by gavage for 12 weeks. The QAE supplementation reduced homeostasis model assessment insulin resistance (HOMA-IR), kidney malfunction, and glomerular hypertrophy in T2DM. Moreover, the QAE treatment significantly attenuated renal NLRP3 inflammasome dependent hyper-inflammation and consequential renal damage caused by oxidative stress, apoptosis, and fibrosis in T2DM. Furthermore, QAE normalized aberrant energy metabolism (downregulation of p-AMPK, sirtuin (SIRT)-1, and PPARγ-coactivator α (PGC-1 α)) in T2DM mice. Taken together, the results suggested that QAE as a natural product has ameliorative effects on renal damage by regulation of oxidative stress and inflammation in T2DM.

Lespedeza bicolor Extract Ameliorated Renal Inflammation by Regulation of NLRP3 Inflammasome-Associated Hyperinflammation in Type 2 Diabetic Mice

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by hyperglycemia. The chronic hyperglycemic condition causes hyperinflammation via activation of nucleotide-binding oligomerization domain-like pyrin domain containing receptor 3 (NLRP3) inflammasome and abnormally leads to morphological and functional changes in kidney. A previous study showed a protective effect of Lespedeza bicolor extract (LBE) on endothelial dysfunction induced by methylglyoxal glucotoxicity. We aimed to investigate whether LBE ameliorated renal damage through regulation of NLRP3 inflammasome-dependent hyper-inflammation in T2DM mice. After T2DM induction by a high fat diet and low dose of streptozotocin (30 mg/kg), the mice were administered with different dosages of LBE (100 or 250 mg/kg/day) by gavage for 12 weeks. LBE supplementation ameliorated kidney dysfunction demonstrated by urine albumin-creatinine at a low dose and plasma creatinine, blood urea nitrogen (BUN), and glomerular hypertrophy at a high dose. Furthermore, a high dose of LBE supplementation significantly attenuated renal hyper-inflammation associated with NLRP3 inflammasome and oxidative stress related to nuclear factor erythroid 2-related factor 2 (Nrf-2) in T2DM mice. Meanwhile, a low dose of LBE supplementation up-regulated energy metabolism demonstrated by phosphorylation of adenosine monophosphate kinase (AMPK) and Sirtuin (SIRT)-1 in T2DM mice. In conclusion, the current study suggested that LBE, in particular, at a high dose could be used as a beneficial therapeutic for hyperglycemia-induced renal damage in T2DM.

The peroxisome proliferator-activated receptor-β/δ antagonist GSK0660 mitigates retinal cell inflammation and leukostasis

Diabetic retinopathy (DR) is triggered by retinal cell damage stimulated by the diabetic milieu, including increased levels of intraocular free fatty acids. Free fatty acids may serve as an initiator of inflammatory cytokine release from Müller cells, and the resulting cytokines are potent stimulators of retinal endothelial pathology, such as leukostasis, vascular permeability, and basement membrane thickening. Our previous studies have elucidated a role for peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) in promoting several steps in the pathologic cascade in DR, including angiogenesis and expression of inflammatory mediators. Furthermore, PPARβ/δ is a known target of lipid signaling, suggesting a potential role for this transcription factor in fatty acid-induced retinal inflammation. Therefore, we hypothesized that PPARβ/δ stimulates both the induction of inflammatory mediators by Müller cells as well the paracrine induction of leukostasis in endothelial cells (EC) by Müller cell inflammatory products. To test this, we used the PPARβ/δ inhibitor, GSK0660, in primary human Müller cells (HMC), human retinal microvascular endothelial cells (HRMEC) and mouse retina. We found that palmitic acid (PA) activation of PPARβ/δ in HMC leads to the production of pro-angiogenic and/or inflammatory cytokines that may constitute DR-relevant upstream paracrine inflammatory signals to EC and other retinal cells. Downstream, EC transduce these signals and increase their synthesis and release of chemokines such as CCL8 and CXCL10 that regulate leukostasis and other cellular events related to vascular inflammation in DR. Our results indicate that PPARβ/δ inhibition mitigates these upstream (MC) as well as downstream (EC) inflammatory signaling events elicited by metabolic stimuli and inflammatory cytokines. Therefore, our data suggest that PPARβ/δ inhibition is a potential therapeutic strategy against early DR pathology.

Potential Interplay between Dietary Saturated Fats and Genetic Variants of the NLRP3 Inflammasome to Modulate Insulin Resistance and Diabetes Risk: Insights from a Meta-Analysis of 19 005 Individuals

SCOPE

Insulin resistance (IR) and inflammation are hallmarks of type 2 diabetes (T2D). The nod-like receptor pyrin domain containing-3 (NLRP3) inflammasome is a metabolic sensor activated by saturated fatty acids (SFA) initiating IL-1β inflammation and IR. Interactions between SFA intake and NLRP3-related genetic variants may alter T2D risk factors.

METHODS

Meta-analyses of six Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium (n = 19 005) tested interactions between SFA and NLRP3-related single-nucleotide polymorphisms (SNPs) and modulation of fasting insulin, fasting glucose, and homeostasis model assessment of insulin resistance.

RESULTS

SFA interacted with rs12143966, wherein each 1% increase in SFA intake increased insulin by 0.0063 IU mL-1 (SE ± 0.002, p = 0.001) per each major (G) allele copy. rs4925663, interacted with SFA (β ± SE = -0.0058 ± 0.002, p = 0.004) to increase insulin by 0.0058 IU mL-1 , per additional copy of the major (C) allele. Both associations are close to the significance threshold (p < 0.0001). rs4925663 causes a missense mutation affecting NLRP3 expression.

CONCLUSION

Two NLRP3-related SNPs showed potential interaction with SFA to modulate fasting insulin. Greater dietary SFA intake accentuates T2D risk, which, subject to functional validation, may be further elaborated depending on NLRP3-related genetic variants.

Detection of metabolic syndrome burden in healthy young adults may enable timely introduction of disease prevention

INTRODUCTION

Metabolic syndrome and associated diseases are a global health problem. Detection of early metabolic modifications that may lead to metabolic syndrome would enable timely introduction of preventive lifestyle modifications.

MATERIAL AND METHODS

In total 103 young, healthy adults were assessed for indicators of metabolic alterations. Anthropometric, lifestyle, genetic and biochemical parameters were assessed. Individuals who fulfilled at least one criterion for diagnosis of metabolic syndrome were assigned to the group with the higher metabolic syndrome burden (B-MeS).

RESULTS

The 34 young healthy individuals who were assigned to the B-MeS group had lower fat-free mass, higher body mass index, waist-to-hip ratio, fat mass, and blood pressure, more visceral fat, they were less physically active, had higher C-reactive protein values and higher catalase activity. Their phenotype was more similar to that of patients diagnosed with metabolic syndrome than the rest of the population.

CONCLUSIONS

Simple anthropometric measurements, lifestyle assessment and basic biochemical measurements can be used to identify young healthy individuals with increased risk for metabolic syndrome. These assessments can be performed at periodic check-ups of the healthy population so that timely diagnosis of B-MeS can be made. As lifestyle factors have a big influence on development or improvement of the MeS, the timely diagnosis for B-MeS would enable an early opportunity for intervention for lifestyle modification in the still healthy population, saving costs and reducing disability adjusted life years.

The effect of NLRP inflammasome on the regulation of AGEs-induced inflammatory response in human periodontal ligament cells

BACKGROUND AND OBJECTIVE

Diabetes influences the frequency and development of periodontitis. Inflammation of human periodontal ligament cells (HPDLCs) participates in this pathologic process. Hence, this study aims to explore whether advanced glycation end products (AGEs), by-products of diabetes, could exaggerate inflammation induced by muramyl dipeptide (MDP) in HPDLCs, and whether nucleotide-binding oligomerization domain-like receptors (NLRs) signaling pathway was involved.

MATERIAL AND METHODS

Human periodontal ligament cells were pre-treated with 100 μg/mL AGEs for 24 hours and stimulated with 10 μg/mL MDP for 24 hours. IL-6, IL-1β, and RAGE were detected, and the activation of NF-κB signaling pathway was observed. The expression of NLRs was evaluated with or without silencing RAGE or blocking NF-κB pathway under AGEs stimulation. Statistical analyses were performed by using independent sample t test.

RESULTS

Advanced glycation end products induced significant increase of inflammatory cytokines in HPDLCs (P < 0.05). Results of western blot (WB) showed that after 45 minutes stimulation of AGEs, p-p65/p65 ratio peaked; AGEs promoted the expression of NLRP1, NLRP3, and apoptosis-associated speck-like protein containing a CARD (ASC). After silencing RAGE or blocking NF-κB pathway, the up-regulation of NLRs protein caused by AGEs was attenuated. Additionally, AGEs pre-treatment could enhance the inflammatory response of MDP and the expression of NLRs, which were demonstrated by more expression of IL-6, IL-1β, NOD2, NLRP1, NLRP3, and ASC.

CONCLUSION

Advanced glycation end products induced inflammatory response in HPDLCs via NLRP1-inflammasome and NLRP3-inflammasome activation in which NF-κB signal pathway was involved. Besides, AGEs promoted the inflammatory response of MDP via NOD2, NLRP1-inflammasome, and NLRP3-inflammasome.

NLRP3 inflammasome inhibition with MCC950 improves diabetes-mediated cognitive impairment and vasoneuronal remodeling after ischemia

Diabetes increases the risk and worsens the progression of cognitive impairment via the greater occurrence of small vessel disease and stroke. Yet, the underlying mechanisms are not fully understood. It is now accepted that cardiovascular health is critical for brain health and any neurorestorative approaches to prevent/delay cognitive deficits should target the conceptual neurovascular unit (NVU) rather than neurons alone. We have recently shown that there is augmented hippocampal NVU remodeling after a remote ischemic injury in diabetes. NLRP3 inflammasome signaling has been implicated in the development of diabetes and neurodegenerative diseases, but little is known about the impact of NLRP3 activation on functional and structural interaction within the NVU of hippocampus, a critical part of the brain that is involved in forming, organizing, and storing memories. Endothelial cells are at the center of the NVU and produce trophic factors such as brain derived neurotrophic factor (BDNF) contributing to neuronal survival, known as vasotrophic coupling. Therefore, the aims of this study focused on two hypotheses: 1) diabetes negatively impacts hippocampal NVU remodeling and worsens cognitive outcome after stroke, and 2) NLRP3 inhibition with MCC950 will improve NVU remodeling and cognitive outcome following stroke via vasotrophic (un)coupling between endothelial cells and hippocampal neurons. Stroke was induced through a 90-min transient middle cerebral artery occlusion (MCAO) in control and high-fat diet/streptozotocin-induced (HFD/STZ) diabetic male Wistar rats. Saline or MCC950 (3 mg/kg), an inhibitor of NLRP3, was injected at 1 and 3 h after reperfusion. Cognition was assessed over time and neuronal density, blood-brain barrier (BBB) permeability as well as NVU remodeling (aquaporin-4 [AQP4] polarity) was measured on day 14 after stroke. BDNF was measured in endothelial and hippocampal neuronal cultures under hypoxic and diabetes-mimicking condition with and without NLRP3 inhibition. Diabetes increased neuronal degeneration and BBB permeability, disrupted AQP4 polarity, impaired cognitive function and amplified NLRP3 activation after ischemia. Inhibition with MCC950 improved cognitive function and vascular integrity after stroke in diabetic animals and prevented hypoxia-mediated decrease in BDNF secretion. These results are the first to provide essential data showing MCC950 has the potential to become a therapeutic to prevent neurovascular remodeling and worsened cognitive decline in diabetic patients following stroke.

The prevalence of pre-diabetes and diabetes and their associated factors in Northeast China: a cross-sectional study

This study investigates the prevalence of pre-diabetes and diabetes and their associated risk factors among adults in Northeast China. A multistage stratified cluster sampling method was used to select adults from Jilin Province. Out of an initial recruitment of 23,050 individuals, 21,435 participants completed an interview and medical examination. The estimated prevalence of diabetes and pre-diabetes were 9.1% and 19.8%, respectively. The prevalence of hypertension, dyslipidemia, and obesity were the highest in participants with previously diagnosed diabetes. Participants who were previously diagnosed with diabetes were more likely to be aware of their hypertension and dyslipidemia status. Participants who were older, male, more educated, or who were widows or widowers were at greater risk for pre-diabetes. Similarly, those who were current drinkers or smokers, had higher BMI or waist circumference, had a family history of diabetes, or who reported they lived in urban areas or had low physical activity levels had increased pre-diabetes risk. The observed levels of diabetes and pre-diabetes in this study indicate that the medical authority needs to focus more attention in this area, and that health monitoring is essential to improving the health awareness of its residents.

The activation of retinal HCA2 receptors by systemic beta-hydroxybutyrate inhibits diabetic retinal damage through reduction of endoplasmic reticulum stress and the NLRP3 inflammasome

OBJECTIVE

The role of the hydroxycarboxylic acid receptor 2 (HCA2) in the retinal damage induced by diabetes has never been explored. In this context, the present study highlights an upregulation of retinal HCA2 receptors in diabetic C57BL6J mice. Moreover, we illustrate that HCA2 receptors exert an anti-inflammatory effect on the retinal damage induced by diabetes when activated by the endogenous ligand β-hydroxybutyrate.

METHODOLOGY

Seven-to-10-week-old C57BL6J mice were rendered diabetic by a single intraperitoneal injection of streptozotocin (75 mg/kg of body weight) and monitored intermittently over a 10-week period extending from the initial diabetes assessment. Mice with a fasting blood glucose level higher than 250 mg/dl for 2 consecutive weeks after streptozotocin injection were treated twice a week with intraperitoneal injections of 25-50-100 mg/kg β-hydroxybutyrate.

RESULTS

Interestingly, while the retinal endoplasmic reticulum stress markers (pPERK, pIRE1, ATF-6α) were elevated in diabetic C57BL6J mice, their levels were significantly reduced by the systemic intraperitoneal treatment with 50 mg/kg and 100 mg/kg β-hydroxybutyrate. These mice also exhibited high NLRP3 inflammasome activity and proinflammatory cytokine levels. In fact, the elevated levels of retinal NLRP3 inflammasome activation markers (NLRP3, ASC, caspase-1) and of the relative proinflammatory cytokines (IL-1β, IL-18) were significantly reduced by 50 mg/kg and 100 mg/kg β-hydroxybutyrate treatment. These doses also reduced the high apoptotic cell number exhibited by the diabetic mice in the retinal outer nuclear layer (ONL) and increased the ONL low connexin 43 expression, leading to an improvement in retinal permeability and homeostasis.

CONCLUSIONS

These data suggest that the systemic treatment of diabetic C57BL6J mice with BHB activates retinal HCA2 and inhibits local damage.

Dual Role of PTPN22 but Not NLRP3 Inflammasome Polymorphisms in Type 1 Diabetes and Celiac Disease in Children

Genetic polymorphisms in genes coding for inflammasome components nucleotide-binding oligomerization domain leucine rich repeat and pyrin domain-containing protein 3 (NLRP3) and caspase recruitment domain-containing protein 8 (CARD8) have been associated with autoinflammatory and autoimmune diseases. On the other hand several studies suggested that NLRP3 inflammasome contributes to maintenance of gastrointestinal immune homeostasis and that activation of NLRP3 is regulated by protein tyrosine phosphatase non-receptor 22 (PTPN22). PTPN22 polymorphism was implicated in the risk for various autoimmune diseases including type 1 diabetes (T1D) but not for celiac disease (CD). The aim of our study was to evaluate the role of inflammasome related polymorphisms in subjects with either T1D or CD as well as in subjects affected by both diseases. We examined PTPN22 rs2476601 (p.Arg620Trp), NLRP3 rs35829419 (p.Gln705Lys), and CARD8 rs2043211 (p.Cys10Ter) in 66 subjects with coexisting T1D and CD, 65 subjects with T1D who did not develop CD, 67 subjects diagnosed only with CD and 127 healthy unrelated Slovenian individuals. All results were adjusted for clinical characteristic and human leukocyte antigen (HLA) risk. PTPN22 rs2476601 allele was significantly more frequent among subjects with T1D (P_adj = 0.001) and less frequent in subjects with CD (P_adj = 0.039) when compared to controls. In patients with coexisting T1D and CD this variant was significantly less frequent compared to T1D group (P_adj = 0.010). Protective effect on CD development in individuals with T1D was observed only within the low risk HLA group. On the other hand, we found no association of NLRP3 rs35829419 and CARD8 rs2043211 with the development of T1D, CD or both diseases together. In conclusion PTPN22 rs2476601polymorphism was significantly associated with the risk of developing T1D in Slovenian population, while no associations of proinflammatory NLRP3 and CARD8 polymorphisms with T1D and CD were observed. Interestingly, the same PTPN22 variant protected from CD. We hypothesize that this effect may be mediated through the NLRP3 inflammasome activation.

Mitochondria, the NLRP3 Inflammasome, and Sirtuins in Type 2 Diabetes: New Therapeutic Targets

SIGNIFICANCE

Type 2 diabetes mellitus and hyperglycemia can lead to the development of comorbidities such as atherosclerosis and microvascular/macrovascular complications. Both type 2 diabetes and its complications are related to mitochondrial dysfunction and oxidative stress. Type 2 diabetes is also a chronic inflammatory condition that leads to inflammasome activation and the release of proinflammatory mediators, including interleukins (ILs) IL-1β and IL-18. Moreover, sirtuins are energetic sensors that respond to metabolic load, which highlights their relevance in metabolic diseases, such as type 2 diabetes. Recent Advances: Over the past decade, great progress has been made in clarifying the signaling events regulated by mitochondria, inflammasomes, and sirtuins. Nod-like receptor family pyrin domain containing 3 (NLRP3) is the best characterized inflammasome, and the generation of oxidant species seems to be critical for its activation. NLRP3 inflammasome activation and altered sirtuin levels have been observed in type 2 diabetes. Critical Issue: Despite increasing evidence of the relationship between the NLRP3 inflammasome, mitochondrial dysfunction, and oxidative stress and of their participation in type 2 diabetes physiopathology, therapeutic strategies to combat type 2 diabetes that target NLRP3 inflammasome and sirtuins are yet to be consolidated.

FUTURE DIRECTIONS

In this review article, we attempt to provide an overview of the existing literature concerning the crosstalk between mitochondrial impairment and the inflammasome, with particular attention to cellular and mitochondrial redox metabolism and the potential role of the NLRP3 inflammasome and sirtuins in the pathogenesis of type 2 diabetes. In addition, we discuss potential targets for therapeutic intervention based on these molecular interactions. Antioxid. Redox Signal. 29, 749-791.

Induction of adaptive immune response by self-aggregating peptides

INTRODUCTION

Recently, subunit vaccines are replacing some of the traditional vaccines because they offer a higher margin of safety. However, generally subunit vaccines have low antigenicity. Adjuvants are used in vaccine formulations to increase their immunogenicity, but current research suggests that adjuvants could induce serious side effects in susceptible individuals; therefore, the improvement of antigens and adjuvants is important.

AREAS COVERED

Here we reviewed some self-aggregating peptides (SAPs) used as antigen delivery systems. SAPs are based on a short sequence of amino acids, which have self-aggregating properties, inducing self-interaction among peptide molecules by means of non-covalent interactions to generate nanoparticles (NPs).

EXPERT COMMENTARY

SAPs increase the immunogenicity of fused/conjugated antigens because they can interact with antigen-presenting cells and induce adaptive immunity based on both humoral and cellular responses. As an example, we report an antigen delivery system based on SAPs forming NPs. These NPs are synthesized using a recombinant baculovirus. We fused the green fluorescent protein to the first 110 amino acids of polyhedrin protein from Autographa californica nucleopolyhedrovirus, which has self-aggregating properties. We showed that these NPs prompt high antibody levels without inducing inflammation, similarly to some SAPs reported here.

Locus and gene-based GWAS meta-analysis identifies new diabetic nephropathy genes

Objective Assimilation of SNPs Interacting in Synchrony (OASIS) is a locus-based clustering algorithm recently described that can potentially address false positives and negatives in genome-wide association studies (GWAS) of complex disorders. Diabetic nephropathy (DN) is incompletely understood due to a paucity of genes identified despite several GWAS. OASIS was applied to three DN dbGAP GWAS datasets (4725 subjects; 1.06 million SNPs). OASIS identified 19 DN genes which were verified using single variant replication in a standard association study and gene-based analysis using GATES. CARS and FRMD3 were confirmed as DN genes, and five known diabetes-associated genes, viz. NLRP3, INPPL1, PIK3C2G, NRXN3, and TBC1D4, not previously identified using these datasets were discovered. Furthermore, three additional novel DN genes were found which replicated in two sets of analysis, viz. NTN1, EBF2, and DNAH11. Hence, composite analysis with OASIS, gene-based, and single variant association testing can be universally applied to existing GWAS datasets for the identification of new genes.

Mediterranean Diet, Glucose Homeostasis, and Inflammasome Genetic Variants: The CORDIOPREV Study

SCOPE

Insulin resistance (IR) and chronic low-grade inflammation are hallmarks of type 2 diabetes mellitus (T2DM). The "NOD-like receptor pyrin domain containing-3" (NLRP3) inflammasome component of innate immunity is a metabolic stress sensor modulated by dietary and genetics factors. The aim of this study was to evaluate the effects of the consumption of two diets for 3 years, Mediterranean (Med) and low fat, on glucose homeostasis in the 1002 coronary heart disease patients of the CORDIOPREV study, according to a genetic variant of NLRP3 inflammasome.

METHODS AND RESULTS

The study was conducted in the framework of the CORDIOPREV study, a randomized dietary intervention with Med and low-fat diets. Single nucleotide polymorphisms (SNPs) located at inflammasome NLRP3 gene were genotyped by OpenArray platform. Nondiabetic CT+TT carriers of the rs4612666 SNP and AG+AA carriers of the rs10733113 SNP increased insulin sensitivity index (ISI) after 3 years of dietary intervention, whereas no effect was observed in diabetic patients. Further analysis by diet showed that the improvement of the ISI in nondiabetic rs10733113 AG+AA carriers was specific to the consumption of the Med diet.

CONCLUSION

Our results show that the benefits associated with a Med diet regarding glucose homeostasis in non-T2DM patients depend on genetic variation in the inflammasome.

Oxidative Stress and NLRP3-Inflammasome Activity as Significant Drivers of Diabetic Cardiovascular Complications: Therapeutic Implications

It is now increasingly appreciated that inflammation is not limited to the control of pathogens by the host, but rather that sterile inflammation which occurs in the absence of viral or bacterial pathogens, accompanies numerous disease states, none more so than the complications that arise as a result of hyperglycaemia. Individuals with type 1 or type 2 diabetes mellitus (T1D, T2D) are at increased risk of developing cardiac and vascular complications. Glucose and blood pressure lowering therapies have not stopped the advance of these morbidities that often lead to fatal heart attacks and/or stroke. A unifying mechanism of hyperglycemia-induced cellular damage was initially proposed to link elevated blood glucose levels with oxidative stress and the dysregulation of metabolic pathways. Pre-clinical evidence has, in most cases, supported this notion. However, therapeutic strategies to lessen oxidative stress in clinical trials has not proved efficacious, most likely due to indiscriminate targeting by antioxidants such as vitamins. Recent evidence now suggests that oxidative stress is a major driver of inflammation and vice versa, with the latest findings suggesting not only a key role for inflammatory pathways underpinning metabolic and haemodynamic dysfunction in diabetes, but furthermore that these perturbations are driven by activation of the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome. This review will address these latest findings with an aim of highlighting the interconnectivity between oxidative stress, NLRP3 activation and inflammation as it pertains to cardiac and vascular injury sustained by diabetes. Current therapeutic strategies to lessen both oxidative stress and inflammation will be emphasized. This will be placed in the context of improving the burden of these diabetic complications.

Locus and gene-based GWAS meta-analysis identifies new diabetic nephropathy genes

Objective Assimilation of SNPs Interacting in Synchrony (OASIS) is a locus-based clustering algorithm recently described that can potentially address false positives and negatives in genome-wide association studies (GWAS) of complex disorders. Diabetic nephropathy (DN) is incompletely understood due to a paucity of genes identified despite several GWAS. OASIS was applied to three DN dbGAP GWAS datasets (4725 subjects; 1.06 million SNPs). OASIS identified 19 DN genes which were verified using single variant replication in a standard association study and gene-based analysis using GATES. CARS and FRMD3 were confirmed as DN genes, and five known diabetes-associated genes, viz. NLRP3, INPPL1, PIK3C2G, NRXN3, and TBC1D4, not previously identified using these datasets were discovered. Furthermore, three additional novel DN genes were found which replicated in two sets of analysis, viz. NTN1, EBF2, and DNAH11. Hence, composite analysis with OASIS, gene-based, and single variant association testing can be universally applied to existing GWAS datasets for the identification of new genes.

NLRP3 Inflammasome Expression and Signaling in Human Diabetic Wounds and in High Glucose Induced Macrophages

Introduction. To investigate the contribution and mechanism of NLRP3 inflammasome expression in human wounds in diabetes mellitus and in high glucose induced macrophages. Methods. In the present study, we compared the expression of NLRP3 inflammasome in debridement wound tissue from diabetic and nondiabetic patients. We also examined whether high glucose induces NLRP3 inflammasome expression in cultures THP-1-derived macrophages and the influence on IL-1β expression. Results. The expressions of NLRP3, caspase1, and IL-1β, at both the mRNA and protein level, were significantly higher in wounds of diabetic patients compared with nondiabetic wounds (P < 0.05). High glucose induced a significant increase in NLRP3 inflammasome and IL-1β expression in THP-1-derived macrophages. M1 macrophage surface marker with CCR7 was significantly upregulated after high glucose stimulation. SiRNA-mediated silencing of NLRP3 expression downregulates the expression of IL-1β. Conclusion. The higher expression of NLRP3, caspase1, and secretion of IL-1β, signaling, and activation might contribute to the hyperinflammation in the human diabetic wound and in high glucose induced macrophages. It may be a novel target to treat the DM patients with chronic wound.

Cerebrovascular complications of diabetes: focus on cognitive dysfunction

The incidence of diabetes has more than doubled in the United States in the last 30 years and the global disease rate is projected to double by 2030. Cognitive impairment has been associated with diabetes, worsening quality of life in patients. The structural and functional interaction of neurons with the surrounding vasculature is critical for proper function of the central nervous system including domains involved in learning and memory. Thus, in this review we explore cognitive impairment in patients and experimental models, focusing on links to vascular dysfunction and structural changes. Lastly, we propose a role for the innate immunity-mediated inflammation in neurovascular changes in diabetes.

Inflammasomes link vascular disease with neuroinflammation and brain disorders

The role of inflammation in neurological disorders is increasingly recognised. Inflammatory processes are associated with the aetiology and clinical progression of migraine, psychiatric conditions, epilepsy, cerebrovascular diseases, dementia and neurodegeneration, such as seen in Alzheimer's or Parkinson's disease. Both central and systemic inflammatory actions have been linked with the development of brain diseases, suggesting that complex neuro-immune interactions could contribute to pathological changes in the brain across multiple temporal and spatial scales. However, the mechanisms through which inflammation impacts on neurological disease are improperly defined. To develop effective therapeutic approaches, it is imperative to understand how detrimental inflammatory processes could be blocked selectively, or controlled for prolonged periods, without compromising essential immune defence mechanisms. Increasing evidence indicates that common risk factors for brain disorders, such as atherosclerosis, diabetes, hypertension, obesity or infection involve the activation of NLRP3, NLRP1, NLRC4 or AIM2 inflammasomes, which are also associated with various neurological diseases. This review focuses on the mechanisms whereby inflammasomes, which integrate diverse inflammatory signals in response to pathogen-driven stimuli, tissue injury or metabolic alterations in multiple cell types and different organs of the body, could functionally link vascular- and neurological diseases and hence represent a promising therapeutic target.