1,5-Anhydroglucitol attenuates cytokine release and protects mice with type 2 diabetes from inflammatory reactions

1,5-AG suppresses pro-inflammatory polarization of macrophages and promotes the survival of B-ALL in vitro by upregulating CXCL14

B-lineage acute lymphoblastic leukemia (B-ALL) is one of the most common malignancies in children. Despite advances in treatment, the role of the tumor microenvironment in B-ALL remains poorly understood. Among the key components of the immune microenvironment, macrophages play a critical role in the progression of the disease. However, recent research has suggested that abnormal metabolites may influence the function of macrophages, altering the immune microenvironment and promoting tumor growth. Our previous non-targeted metabolomic detection revealed that the metabolite 1,5-anhydroglucitol (1,5-AG) level in the peripheral blood of children newly diagnosed with B-ALL was significantly elevated. Except for its direct influence on leukemia cells, the effect of 1,5-AG on macrophages is still unclear. Herein, we demonstrated new potential therapeutic targets by focusing on the effect of 1,5-AG on macrophages. We used polarization-induced macrophages to determine how 1,5-AG acted on M1-like polarization and screened out the target gene CXCL14 via transcriptome sequencing. Furthermore, we constructed CXCL14 knocked-down macrophages and a macrophage-leukemia cell coculture model to validate the interaction between macrophages and leukemia cells. We discovered that 1,5-AG upregulated the CXCL14 expression, thereby inhibiting M1-like polarization. CXCL14 knockdown restored the M1-like polarization of macrophages and induced leukemia cells apoptosis in the coculture model. Our findings offer new possibilities for the genetic engineering of human macrophages to rehabilitate their immune activity against B-ALL in cancer immunotherapy.

A glucose-like metabolite deficient in diabetes inhibits cellular entry of SARS-CoV-2

The severity and mortality of COVID-19 are associated with pre-existing medical comorbidities such as diabetes mellitus. However, the underlying causes for increased susceptibility to viral infection in patients with diabetes is not fully understood. Here we identify several small-molecule metabolites from human blood with effective antiviral activity against SARS-CoV-2, one of which, 1,5-anhydro-D-glucitol (1,5-AG), is associated with diabetes mellitus. The serum 1,5-AG level is significantly lower in patients with diabetes. In vitro, the level of SARS-CoV-2 replication is higher in the presence of serum from patients with diabetes than from healthy individuals and this is counteracted by supplementation of 1,5-AG to the serum from patients. Diabetic (db/db) mice undergo SARS-CoV-2 infection accompanied by much higher viral loads and more severe respiratory tissue damage when compared to wild-type mice. Sustained supplementation of 1,5-AG in diabetic mice reduces SARS-CoV-2 loads and disease severity to similar levels in nondiabetic mice. Mechanistically, 1,5-AG directly binds the S2 subunit of the SARS-CoV-2 spike protein, thereby interrupting spike-mediated virus-host membrane fusion. Our results reveal a mechanism that contributes to COVID-19 pathogenesis in the diabetic population and suggest that 1,5-AG supplementation may be beneficial to diabetic patients against severe COVID-19.

Plasma 1,5-anhydro-D-glucitol is associated with peripheral nerve function and diabetic peripheral neuropathy in patients with type 2 diabetes and mild-to-moderate hyperglycemia

BACKGROUND

Plasma 1,5-anhydro-D-glucitol (1,5-AG) may be a easily accessible marker for glycemic variability under mild-to-moderate hyperglycemia. The present study was to investigate the association of 1,5-AG with peripheral nerve function and diabetic peripheral neuropathy (DPN) in patients with T2D and mild-to-moderate hyperglycemia.

METHODS

We recruited 574 T2D patients with mild-to-moderate hyperglycemia (HbA1c  < 8.0%) for this cross-sectional study, with plasma 1,5-AG synchronously detected. All patients were questioned for neurologic symptoms, examined for neurologic signs and screened for peripheral nerve function. Nerve function included the latency, amplitude and nerve conduction velocity (NCV) of limbs nerves (median, ulnar nerve, common peroneal, superficial peroneal, tibial and sural nerve). Besides, composite Z-score of latency, amplitude and NCV were calculated. DPN was identified as both at least a neurologic symptom/sign and an abnormality of peripheral nerve function.

RESULTS

Among the recruited patients, 23.9% (n  = 137) were identified to be with DPN, and the prevalence of DPN decreased from 36.6%, 24.5%, 21.2%, 13.3% from first (Q1), second (Q2), and third (Q3) to fourth quartile (Q4) of 1,5-AG. Moreover, multivariable linear regression analysis showed 1,5-AG was associated with composite Z-score of nerve latency (β  = - 0.18, t  = - 3.84, p  < 0.001), amplitude(β  =  0.26, t  = 5.35, p  < 0.001) and NCV (β  = 0.24, t  = 5.61, p  < 0.001), respectively. Furthermore, compared to Q4 of 1,5-AG as reference, the adjusted odds ratios and 95% CIs for DPN of Q3, Q2, and Q1 were 1.29(0.59-2.81), 1.85(0.87-3.97), and 2.72(1.16-6.34), respectively. Additionally, receiver operating characteristic analysis revealed that optimal cutoff value of 1,5-AG to indicate DPN was  ≤ 30.8 μmol/L, with sensitivity of 56.20% and specificity of 66.36%.

CONCLUSIONS

Low plasma 1,5-AG is closely associated with impaired peripheral nerve function and DPN in T2D patients under mild-to-moderate hyperglycemia.

ARHGAP24 ameliorates inflammatory response through inactivating Rac1/Akt/NF-κB pathway in acute pneumonia model of rat

Background

ARHGAP24 might play a protective effect in the development of acute pneumonia, but the underlying mechanism remained a mystery. We aimed to investigate the effect of ARHGAP24 and explore the protective mechanism based on the acute pneumonia model of rats.

Methods

Western blotting analysis was conducted to measure the expression of ARHGAP24 in the rat model of bacillus pyocyaneus-induced acute pneumonia after 12, 24, 36, and 48 h modeling. In the acute pneumonia model of rat, lung histopathological change, lung edema, and levels of inflammatory cytokines in the broncho alveolar lavage fluid (BALF) were respectively measured to comprehensively evaluate the beneficial effect of overexpression of ARHGAP24 mediated by adenovirus. The western blotting analysis was conducted to evaluate Rac1/Akt/NF-κB pathway-related protein expression change with ARHGAP24 overexpression.

Results

We found that ARHGAP24 expression tended to be lower in the acute pneumonia model of the rat after bacillus pyocyaneus treated 12, 24, 36, and 48 h. High expression of ARHGAP24 and a substantial ARHGAP24 positive area was found in the western blotting analysis and immunohistochemical staining in rats transfected with ARHGAP24. In the meantime, overexpression of ARHGAP24 suppressed the development of acute pneumonia through alleviating lung histopathological deterioration, lung edema, and levels of inflammatory cytokines in the BALF of the lung. What is more critical, ARHGAP24 overexpression inhibits the activation of Rac1, Akt, and NF-κB.

Conclusions

Thus, we conclude that ARHGAP24 ameliorated the inflammatory response in the acute pneumonia model of the rat through inactivating the Rac1/Akt/NF-κB pathway.

Comparison of Pulmonary and Systemic NO- and PGI2-Dependent Endothelial Function in Diabetic Mice

Diabetes increases the risk of pulmonary hypertension and is associated with alterations in pulmonary vascular function. Still, it is not clear whether alterations in the phenotype of pulmonary endothelium induced by diabetes are distinct, as compared to peripheral endothelium. In the present work, we characterized differences between diabetic complications in the lung and aorta in db/db mice with advanced diabetes. Male, 20-week-old db/db mice displayed increased HbA1c and glucose concentration compatible with advanced diabetes. Diabetic lungs had signs of mild fibrosis, and pulmonary endothelium displayed significantly ultrastructural changes. In the isolated, perfused lung from db/db mice, filtration coefficient (K_f,c) and contractile response to TXA₂ analogue were enhanced, while endothelial NO-dependent modulation of pulmonary response to hypoxic ventilation and cumulative production of NO₂⁻ were impaired, with no changes in immunostaining for eNOS expression. In turn, 6-keto-PGF_1α release from the isolated lung from db/db mice was increased, as well as immunostaining of thrombomodulin (CD141). In contrast to the lung, NO-dependent, acetylcholine-induced vasodilation, ionophore-stimulated NO₂⁻ generation, and production of 6-keto-PGF_1α were all impaired in aortic rings from db/db mice. Although eNOS immunostaining was not changed, that of CD141 was clearly lowered. Interestingly, diabetes-induced nitration of proteins in aorta was higher than that in the lungs. In summary, diabetes induced marked ultrastructural changes in pulmonary endothelium that were associated with the increased permeability of pulmonary microcirculation, impaired NO-dependent vascular function, with compensatory increase in PGI₂ production, and increased CD141 expression. In contrast, endothelial dysfunction in the aorta was featured by impaired NO-, PGI₂-dependent function and diminished CD141 expression.

Cerebral ischemic damage in diabetes: an inflammatory perspective

Stroke is one of the leading causes of death worldwide. A strong inflammatory response characterized by activation and release of cytokines, chemokines, adhesion molecules, and proteolytic enzymes contributes to brain damage following stroke. Stroke outcomes are worse among diabetics, resulting in increased mortality and disabilities. Diabetes involves chronic inflammation manifested by reactive oxygen species generation, expression of proinflammatory cytokines, and activation/expression of other inflammatory mediators. It appears that increased proinflammatory processes due to diabetes are further accelerated after cerebral ischemia, leading to increased ischemic damage. Hypoglycemia is an intrinsic side effect owing to glucose-lowering therapy in diabetics, and is known to induce proinflammatory changes as well as exacerbate cerebral damage in experimental stroke. Here, we present a review of available literature on the contribution of neuroinflammation to increased cerebral ischemic damage in diabetics. We also describe the role of hypoglycemia in neuroinflammation and cerebral ischemic damage in diabetics. Understanding the role of neuroinflammatory mechanisms in worsening stroke outcome in diabetics may help limit ischemic brain injury and improve clinical outcomes.

Metabolomic biomarkers predictive of early structural lung disease in cystic fibrosis

Neutrophilic airway inflammation plays a role in early structural lung disease in cystic fibrosis, but the mechanisms underlying this pathway are incompletely understood.Metabolites associated with neutrophilic inflammation were identified by discovery metabolomics on bronchoalveolar lavage fluid supernatant from 20 preschool children (2.9±1.3 years) with cystic fibrosis. Targeted mass-spectrometric detection of relevant metabolites was then applied to 34 children (3.5±1.5 years) enrolled in the Australian Respiratory Early Surveillance Team for Cystic Fibrosis (AREST CF) who underwent chest computed tomography and bronchoalveolar lavage from two separate lobes during 42 visits. Relationships between metabolites and localised structural lung disease were assessed using multivariate analyses.Discovery metabolomics identified 93 metabolites associated with neutrophilic inflammation, including pathways involved in metabolism of adenyl purines, amino acids and small peptides, cellular energy and lipids. In targeted mass spectrometry, products of adenosine metabolism, protein catabolism and oxidative stress were associated with structural lung disease and predicted future bronchiectasis, and activities of enzymes associated with adenosine metabolism were elevated in the samples with early disease.Metabolomics analyses revealed metabolites and pathways altered with neutrophilic inflammation and destructive lung disease. These pathways can serve as biomarkers and potential therapeutic targets for early cystic fibrosis lung disease.

1,5-anhydroglucitol is associated with early-phase insulin secretion in chinese patients with newly diagnosed type 2 diabetes mellitus

BACKGROUND

The goal of the present study was to explore the correlations of 1,5-anhydroglucitol (l,5-AG), glycated hemoglobin (HbA1c), and glycated albumin (GA) with insulin sensitivity and secretion.

SUBJECTS AND METHODS

In total, 302 patients with newly diagnosed type 2 diabetes mellitus (166 men, 136 women) were enrolled in this study. The homeostasis model assessment for insulin resistance (HOMA-IR) and homeostasis model assessment for β-cell function (HOMA-β) were calculated to determine the basal insulin sensitivity and secretion. The insulinogenic index (IGI) was used to evaluate early-phase insulin secretion. 1,5-AG and GA were assayed via the enzymatic method, and HbA1c was detected by high-pressure liquid chromatography.

RESULTS

Among all 302 subjects, the serum 1,5-AG level was 13.1±7.2 μg/mL, and the HbA1c and GA levels [median (interquartile range)] were 6.7% (6.2-7.3%) and 17.7% (16.0-19.5%), respectively. Increased 1,5-AG quartiles were accompanied by trends toward a decreased HOMA-IR and an increased HOMA-β and IGI (for all trends, P<0.001). 1,5-AG was negatively associated with HOMA-IR (r=-0.200, P<0.001) and positively associated with HOMA-β and IGI (r=0.210 and 0.413, respectively; both P<0.001). 1,5-AG was independently related to HOMA-IR and HOMA-β and exhibited an independent positive association with IGI (standardized β=0.242, P<0.001). Additionally, both HbA1c and GA were independently correlated with HOMA-IR and HOMA-β.

CONCLUSIONS

1,5-AG is not only correlated with basal insulin sensitivity and secretion, but also closely associated with early-phase insulin secretion in Chinese patients with newly diagnosed type 2 diabetes mellitus.

Effects of cranberry powder on biomarkers of oxidative stress and glucose control in db/db mice

Increased oxidative stress in obese diabetes may have causal effects on diabetic complications, including dyslipidemia. Lipopolysccharides (LPS) along with an atherogenic diet have been found to increase oxidative stress and insulin resistance. Cranberry has been recognized as having beneficial effects on diseases related to oxidative stress. Therefore, we employed obese diabetic animals treated with an atherogenic diet and LPS, with the aim of examining the effects of cranberry powder (CP) on diabetic related metabolic conditions, including lipid profiles, serum insulin and glucose, and biomarkers of oxidative stress. Forty C57BL/KsJ-db/db mice were divided into the following five groups: normal diet + saline, atherogenic diet + saline, atherogenic diet + LPS, atherogenic diet + 5% CP + LPS, and atherogenic diet + 10% CP + LPS. Consumption of an atherogenic diet resulted in elevation of serum total cholesterol and atherogenic index (AI) and reduction of high density lipoprotein (HDL)-cholesterol. However, with 10% CP, the increase in mean HDL-cholesterol level was close to that of the group with a normal diet, whereas AI was maintained at a higher level than that of the group with a normal diet. LPS induced elevated serum insulin level was lowered by greater than 60% with CP (P < 0.05), and mean serum glucose level was reduced by approximately 19% with 5% CP (P > 0.05). Mean activity of liver cytosolic glutathione peroxidase was significantly increased by LPS injection, however it was reduced back to the value without LPS when the diet was fortified with 10% CP (P < 0.05). In groups with CP, a reduction in mean levels of serum protein carbonyl tended to occur in a dose dependent manner. Particularly with 10% CP, a reduction of approximately 89% was observed (P > 0.05). Overall results suggest that fortification of the atherogenic diet with CP may have potential health benefits for obese diabetes with high oxidative stress, by modulation of physical conditions, including some biomarkers of oxidative stress.

Increased 1,5-anhydroglucitol predicts glycemic remission in patients with newly diagnosed type 2 diabetes treated with short-term intensive insulin therapy

BACKGROUND

Short-term intensive insulin therapy has been shown to induce long-term glycemic remission in patients with newly diagnosed type 2 diabetes. However, predictors of remission are still uncertain. This study was conducted to evaluate whether changes of 1,5-anhydroglucitol (1,5AG) and fructosamine (FA) could be a predictor of remission.

SUBJECTS AND METHODS

Newly diagnosed drug-naive patients with type 2 diabetes (n = 64) were enrolled. After baseline assessments, continuous subcutaneous insulin infusion (CSII) was administered in all patients until euglycemia was achieved and maintained for another 2 weeks. Patients were subsequently followed monthly for 3 months. 1,5AG and FA were measured before and after therapy and at 1-month follow-up.

RESULTS

After CSII, A1C and FA decreased from baseline, whereas 1,5AG increased. 1,5AG was higher at 1-month follow-up (11.5 ± 4.1 vs. 6.7 ± 2.8 mg/L, P<0.001), whereas FA was lower (273.1 ± 56.1 vs. 316.2 ± 39.3 μmol/L, P = 0.021) in the remission group. Stepwise logistic regression analysis showed that 1,5AG at 1-month follow-up rather than FA was an independent predictor of remission after adjusting for other confounders (odds ratio 1.56, 95% confidence interval [CI] 1.15-2.12, P = 0.004). The area under the curve of the receiver operating characteristic curve analysis was 0.85 (95% CI 0.75-0.96, P<0.001). The optimal cutoff point for 1,5AG at 1-month follow-up was 8.9 mg/L (specificity, 83.3%; sensitivity, 78.6%).

CONCLUSIONS

Improvement of 1,5AG predicts maintenance of glycemic remission after intensive insulin therapy in patients with newly diagnosed type 2 diabetes.

Effects of N-acetylcysteine on nicotinamide dinucleotide phosphate oxidase activation and antioxidant status in heart, lung, liver and kidney in streptozotocin-induced diabetic rats

PURPOSE

Hyperglycemia increases reactive oxygen species (ROS) and the resulting oxidative stress plays a key role in the pathogenesis of diabetic complications. Nicotinamide dinucleotide phosphate (NADPH) oxidase is one of the major sources of ROS production in diabetes. We, therefore, examined the possibility that NADPH oxidase activation is increased in various tissues, and that the antioxidant N-acetylcysteine (NAC) may have tissue specific effects on NADPH oxidase and tissue antioxidant status in diabetes.

MATERIALS AND METHODS

Control (C) and streptozotocin-induced diabetic (D) rats were treated either with NAC (1.5 g/kg/day) orally or placebo for 4 weeks. The plasma, heart, lung, liver, kidney were harvested immediately and stored for biochemical or immunoblot analysis.

RESULTS

levels of free 15-F(2t)-isoprostane were increased in plasma, heart, lung, liver and kidney tissues in diabetic rats, accompanied with significantly increased membrane translocation of the NADPH oxidase subunit p67phox in all tissues and increased expression of the membrane-bound subunit p22phox in heart, lung and kidney. The tissue antioxidant activity in lung, liver and kidney was decreased in diabetic rats, while it was increased in heart tissue. NAC reduced the expression of p22phox and p67phox, suppressed p67phox membrane translocation, and reduced free 15-F(2t)-isoprostane levels in all tissues. NAC increased antioxidant activity in liver and lung, but did not significantly affect antioxidant activity in heart and kidney.

CONCLUSION

The current study shows that NAC inhibits NADPH oxidase activation in diabetes and attenuates tissue oxidative damage in all organs, even though its effects on antioxidant activity are tissue specific.

Cholesterol: An Inflammatory Compound

Obesity is one of the main rising causes of health problems in modern society and is correlated to type 2 diabetes mellitus, hypertension, heart disease and atherosclerosis. Bacterial products, endogenous substances such as oxidized LDL (ox-LDL) and heat shock proteins mediate activation of Toll-like receptors and reinforce the view that the innate immune system plays a key role in the genesis of atherosclerosis. In addition, natural killer T (NKT) cells respond to lipids presented via CD1d on APCs, and may also be able to affect atherosclerosis. All the main cell types involved in atherosclerosis such as endothelial cells, macrophages, T cells, smooth muscle cells and platelets express proinflammatory cytokines. In addition, CD4 ligation triggers the expression of adhesion molecules, cytokines and matrix metalloprotinease. IL-6 cytokines travels to the liver where it elicits acute phase response resolving in the release of serum amyloid-A C-reactive protein, fibrogen and plasminogen activator inhibitor-1. Therefore increasing body fat mass is associated with high levels of inflammatory cytokines such as IL-1 and TNF. In this study we revisit the interrelationship between fat and inflammation.

What You Should Know about Escherichia Coli Infection

As in Northern Germany there have recently been several deaths caused by Escherichia coli (E.coli), we decided to revisit the effects of E.coli infection. Since this bacteria is the most numerous facultative and aerobic germ in the human intestine, we would like to warn the population of its pathogenicity. In fact, E.coli can be pathogenic both in humans and in animals and can start an inflammatory process, activating some factors of the cell nucleus such as NFkB, with the consequent production of cytokines. E.coli can appear in several strains and can be very aggressive and can contaminate food, water and the environment, causing severe disease, and in some cases death.

Exacerbated brain damage, edema and inflammation in type-2 diabetic mice subjected to focal ischemia

One of the limiting factors in stroke therapeutic development is the use of animal models that do not well represent the underlying medical conditions of patients. In humans, diabetes increases the risk of stroke incidence as well as post-stroke mortality. To understand the mechanisms that render diabetics to increased brain damage, we evaluated the effect of transient middle cerebral artery occlusion in adult db/db mice. The db/db mouse is a model of type-2 diabetes with four times higher blood sugar than its normoglycemic genetic control(db/+ mouse). Following transient middle cerebral artery occlusion, the db/db mice showed significantly higher mortality, bigger infarcts, increased cerebral edema, worsened neurological status compared to db/+ mice. The db/db mice also showed significantly higher post-ischemic inflammatory markers (ICAM1(+) capillaries, extravasated macrophages/neutrophils and exacerbated proinflammatory gene expression) compared to db/+ mice. In addition, the post-ischemic neuroprotective heat-shock chaperone gene expression was curtailed in the db/db compared to db/+ mice.

IL-34 a Newly Discovered Cytokine

In this study we describe some biological effects of IL-34, a newly discovered cytokine. We show that Il-34 stimulates monocyte cell viability and directly modulates the number and function of monocytes and regulates myeloid cell growth and differentiation. Moreover, since IL-34 in mice is involved in osteoporosis, an antagonist of this cytokine could be beneficial for the treatment of this disease.