Molecular and cellular mechanisms linking inflammation to insulin resistance and β-cell dysfunction

Insulin resistance and periodontitis: Mediation by blood pressure

AIM

This study investigated the association between the triglyceride-glucose (TyG) index, a surrogate marker of insulin resistance, and moderate/severe periodontitis and the role of blood pressure as a mediator in this association. A second aim was to assess the role of cardiometabolic conditions such as obesity, hypertension, and dyslipidemia as potential effect modifiers.

METHODS

Data from 5733 US adults aged 30-64 years and with complete periodontal examination were analyzed (NHANES 2011-2014). Participants were classified as having moderate/severe periodontitis or mild/no periodontitis according to the CDC/AAP criteria as the outcome. The exposure was the TyG index, while both systolic (SBP), and diastolic (DBP) blood pressure were tested as mediators using parametric g-formula. Analyses were adjusted for relevant confounders, namely, age, sex, ethnicity, poverty-income ratio, and smoking, using inverse probability treatment weighting. Obesity status (based on a body mass index ≥30 kg/m2), self-report of hypertension and dyslipidemia (calculated based on the thresholds provided by National Cholesterol Education Program-Adult Treatment Panel-III) were tested as effect modifiers.

RESULTS

The findings showed the TyG index to be associated with increased odds of moderate/severe periodontitis [odds ratio (OR), 95% confidence interval (CI) = 1.17 (1.11-1.23)], with 50% of the total effect mediated by SBP. Stratified analysis showed a stronger association in individuals with obesity, hypertension, and dyslipidemia compared to those without these conditions. However, in those taking anti-hypertensive medications, the association was partially mitigated. Sensitivity analysis using imputed data showed consistent results.

CONCLUSION

The TyG index was associated with increased odds of moderate/severe periodontitis, especially in individuals with obesity, hypertension, and dyslipidemia. SBP levels partially mediated this association.

Exploring therapeutic targets and molecular mechanisms for treating diabetes mellitus-associated heart failure with Qishen Yiqi dropping pills: A network pharmacology and bioinformatics approach

Diabetes mellitus (DM) and heart failure frequently coexist, presenting significant public health challenges. QiShenYiQi Dropping Pills (QSDP) are widely employed in the treatment of diabetes mellitus concomitant with heart failure (DM-HF). Nevertheless, the precise mechanisms underlying their efficacy have yet to be elucidated. Active ingredients and likely targets of QSDP were retrieved from the TCMSP and UniProt databases. Genes associated with DM-HF were pinpointed through searches in the GeneCards, OMIM, DisGeNET, and TTD databases. Differential genes connected to DM-HF were sourced from the GEO database. Enrichment analyses via gene ontology and Kyoto Encyclopedia of Genes and Genomes pathways, as well as immune infiltration assessments, were conducted using R software. Further analysis involved employing molecular docking strategies to explore the interactions between the identified targets and active substances in QSDP that are pertinent to DM-HF treatment. This investigation effectively discerned 108 active compounds and 257 targets relevant to QSDP. A protein-protein interaction network was constructed, highlighting 6 central targets for DM-HF treatment via QSDP. Gene ontology enrichment analysis predominantly linked these targets with responses to hypoxia, metabolism of reactive oxygen species, and cytokine receptor interactions. Analysis of Kyoto Encyclopedia of Genes and Genomes pathways demonstrated that these targets mainly participate in pathways linked to diabetic complications, such as AGE-RAGE signaling, dyslipidemia, arteriosclerosis, the HIF-1 signaling pathway, and the tumor necrosis factor signaling pathway. Further, immune infiltration analysis implied that QSDP's mechanism in treating DM-HF might involve immune-mediated inflammation and crucial signaling pathways. Additionally, molecular docking studies showed that the active substances in QSDP have strong binding affinities with these identified targets. This research presents a new model for addressing DM-HF through the use of QSDP, providing novel insights into incorporating traditional Chinese medicine (TCM) principles in the clinical treatment of DM-HF. The implications of these findings are substantial for both clinical application and further scientific inquiry.

Serum immunoglobulin concentrations and risk of type 2 diabetes mellitus in adults: a prospective cohort study from the TCLSIH study

Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by hyperglycemia resulting from defects in insulin secretion and/or insulin action. Increasing evidence suggests that inflammation played an important role in the pathogenesis of T2DM. Prospective studies on the link between immunoglobulins concentrations and the risk of T2DM in adults are limited. We developed a cohort study including 7,093 adults without T2DM history. The incidence of T2DM was 16.45 per 1,000 person-years. Compared with the lowest quartiles, the hazard ratios (95% confidence intervals) of T2DM for the highest quartiles of IgG, IgE, IgM and IgA were 0.64 (0.48-0.85), 0.94 (0.72-1.23), 0.68 (0.50-0.92) and 1.62 (1.24-2.11) (P for trend was < 0.01, 0.84, 0.02 and < 0.0001), respectively, suggesting that serum IgG and IgM concentrations were inversely associated with the incidence of T2DM, and IgA levels were positively associated with the risk of T2DM in a general adult population.

Mechanisms of persistent hemolysis-induced middle kidney injury in grass carp (Ctenopharyngodon idella)

Infection-induced hemolysis results in intravascular hemolysis, which releases hemoglobin (Hb) into the tissues. Free Hb exhibits cytotoxic, oxidative, and pro-inflammatory effects, leading to systemic inflammation, vascular constriction dysfunction, thrombosis, and proliferative vascular lesions. Currently, the impact of intravascular hemolysis on the middle kidney in fish is unclear. Here, the injection of phenylhydrazine (PHZ) was used to establish a persistent hemolysis model in grass carp. The determination results revealed that the PHZ-induced hemolysis caused conspicuous tissue damage in the kidneys of grass carp, increased the levels of Cr in the serum and the expression indicators of kidney injury-related genes in the middle kidney. Prussian blue staining indicated that PHZ-induced hemolysis significantly increased the deposition of iron ions in the kidneys of grass carp, and activated the expression levels of iron metabolism-related genes. The results of oxidative damage-related experiments indicate that under PHZ treatment, the activity of middle kidney cells decreases, and the production of oxidative damage markers malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) increases, simultaneously inhibiting the activity of antioxidant enzymes and upregulating the transcription levels of antioxidant enzyme-related genes. Additionally, the analysis of inflammatory factors revealed a significant upregulation of genes associated with inflammation induced by PHZ-induced hemolysis. The transcriptome analysis was performed to further explore the molecular regulatory effects of hemolysis on tissues, the analysis revealed the treatment of PHZ activated various of programmed cell death (PCD) pathways, including ferroptosis, apoptosis, and autophagy. In summary, this study found that sustained hemolysis in fish results in Hb and iron ion deposition in middle kidney, promoting oxidative damage, ultimately inducing various forms of PCD.

Red Oranges and Olive Leaf Waste-Derived Bioactive Extracts Promote Adipocyte Functionality In Vitro

Obesity is increasingly prevalent worldwide and is linked to metabolic diseases, such as insulin resistance (IR) and type 2 diabetes mellitus (T2DM), due to excessive free fatty acids (FFAs). Although lifestyle changes are effective, they often prove to be insufficient as initial treatments for obesity. Additionally, while surgical and pharmacological interventions are available, they are not entirely safe or effective. Recently, interest has grown in utilizing food waste and plant-derived phenolic compounds for their health benefits, presenting a promising avenue for managing obesity and its related disorders. Indeed, many studies have examined the potential inhibitory effects of the natural extract on adipocyte differentiation and lipid accumulation. This study focused on the evaluation of the effects of standardized extracts obtained from red oranges and olive leaf waste on 3T3-L1 murine pre-adipocyte and adipocyte functionality. Red orange extract (ROE) and olive leaf extract (OLE), alone and in combination, were tested to assess their anti-obesity and anti-inflammatory effects, as well as their potential therapeutic benefits. Three in vitro models were established to investigate the effects of the extracts on (I) adipocyte differentiation; (II) mature and hypertrophic adipocytes challenged with palmitic acid (PA) and erastin (ER), respectively; and (III) erastin-induced cytotoxicity on pre-adipocytes.

GHSR Deletion in β-Cells of Male Mice: Ineffective in Obesity, but Effective in Protecting against Streptozotocin-Induced β-Cell Injury in Aging

Insulin secretion from pancreatic β cells is a key pillar of glucose homeostasis, which is impaired under obesity and aging. Growth hormone secretagogue receptor (GHSR) is the receptor of nutrient-sensing hormone ghrelin. Previously, we showed that β-cell GHSR regulated glucose-stimulated insulin secretion (GSIS) in young mice. In the current study, we further investigated the effects of GHSR on insulin secretion in male mice under diet-induced obesity (DIO) and streptozotocin (STZ)-induced β-cell injury in aging. β-cell-specific-Ghsr-deficient (Ghsr-βKO) mice exhibited no glycemic phenotype under DIO but showed significantly improved ex vivo GSIS in aging. We also detected reduced insulin sensitivity and impaired insulin secretion during aging both in vivo and ex vivo. Accordingly, there were age-related alterations in expression of glucose transporter, insulin signaling pathway, and inflammatory genes. To further determine whether GHSR deficiency affected β-cell susceptibility to acute injury, young, middle-aged, and old Ghsr-βKO mice were subjected to STZ. We found that middle-aged and old Ghsr-βKO mice were protected from STZ-induced hyperglycemia and impaired insulin secretion, correlated with increased expression of insulin signaling regulators but decreased pro-inflammatory cytokines in pancreatic islets. Collectively, our findings indicate that β-cell GHSR has a major impact on insulin secretion in aging but not obesity, and GHSR deficiency protects against STZ-induced β-cell injury in aging.

The Expression of MAFB Gene in Circulating Monocytes Is Related to Chronic Inflammatory Status in T2DM Patients

Immune cell-mediated chronic inflammation is one of the causes of type 2 diabetes mellitus (T2DM). Therefore, identifying inflammatory markers in circulating immune cells is highly important for predicting insulin resistance (IR) and the occurrence of T2DM. In this study, we discovered that differentially expressed genes (DEGs) in peripheral blood mononuclear cells (PBMCs) from T2DM patients were associated with innate immunity and chronic inflammatory responses through bulk transcriptome sequencing (bulk RNA-seq). Gene integration analysis revealed that nine DEGs were upregulated, and receiver operating characteristic (ROC) curve analysis revealed that V-maf musculoaponeurotic fibrosarcoma oncogene homolog B (MAFB), a candidate biomarker, has a certain predictive value for T2DM. In population-based cohort studies, we found that MAFB expression was significantly upregulated in the PBMCs of T2DM patients and was significantly correlated with homeostasis model assessment of IR (HOMA-IR), tumor necrosis factor-α (TNF-α), adiponectin (Adipoq), etc. We further evaluated the sensitivity and specificity of MAFB and other clinical parameters for predicting and diagnosing T2DM and found that MAFB expression in PBMCs had a positive effect on the prediction and diagnosis of T2DM. Finally, single-cell RNA sequencing (scRNA-seq) analysis revealed that the increase in MAFB expression was mainly in nonclassical monocytes. Our results suggest that increased MAFB expression in circulating monocytes may mediate chronic inflammatory status in patients with T2DM. Therefore, MAFB gene expression in circulating monocytes has certain clinical significance for predicting and assisting in the diagnosis of T2DM.

Hematologic DNMT3A reduction and high-fat diet synergize to promote weight gain and tissue inflammation

During aging, blood cell production becomes dominated by a limited number of variant hematopoietic stem cell (HSC) clones. Differentiated progeny of variant HSCs are thought to mediate the detrimental effects of such clonal hematopoiesis on organismal health, but the mechanisms are poorly understood. While somatic mutations in DNA methyltransferase 3A (DNMT3A) frequently drive clonal dominance, the aging milieu also likely contributes. Here, we examined in mice the interaction between high-fat diet (HFD) and reduced DNMT3A in hematopoietic cells; strikingly, this combination led to weight gain. HFD amplified pro-inflammatory pathways and upregulated inflammation-associated genes in mutant cells along a pro-myeloid trajectory. Aberrant DNA methylation during myeloid differentiation and in response to HFD led to pro-inflammatory activation and maintenance of stemness genes. These findings suggest that reduced DNMT3A in hematopoietic cells contributes to weight gain, inflammation, and metabolic dysfunction, highlighting a role for DNMT3A loss in the development of metabolic disorders.

Combination therapy of metformin and morin attenuates insulin resistance, inflammation, and oxidative stress in skeletal muscle of high-fat diet-fed mice

Lipid accumulation, inflammation, and oxidative stress are the most important causes of muscle insulin resistance. The aim of this study was to investigate the single and combined treatment effects of metformin (MET) and morin (MOR) on lipid accumulation, inflammation, and oxidative stress in the skeletal muscle of mice fed a high-fat diet. The mice were supplemented with MET (230 mg/kg diet), MOR (100 mg/kg diet), and MET + MOR for 9 weeks. Our results revealed that single treatment with MET or MOR, and with a stronger effect of MET + MOR combined treatment, reduced body weight gain, improved glucose intolerance and enhanced Akt phosphorylation in the muscle tissue. In addition, plasma and muscle triglyceride levels were decreased after treatment with MET and MOR. The expression of genes involved in macrophage infiltration and polarization and pro-inflammatory cytokines showed that MET + MOR combined treatment, significantly reduced inflammation in the muscle. Furthermore, combined treatment of MET + MOR with greater efficacy than the single treatment improved several oxidative stress markers in the muscle. Importantly, combined treatment of MET and MOR could increase the expression of nuclear factor erythroid 2-related factor 2, the master regulator of the antioxidant response. These findings suggest that combination of MET with MOR might ameliorate insulin resistance, inflammation, and oxidative stress in the skeletal muscle of mice fed high-fat diet.

Potential molecular mechanisms underlying the ameliorative effect of Cola nitida (Vent.) Schott & Endl. on insulin resistance in rat skeletal muscles

ETHNOPHARMACOLOGICAL RELEVANCE

Cola nitida (Vent.) Schott & Endl. are among the common medicinal plants employed in traditional medicine for treating diabetes and its complications.

AIM OF THE STUDY

The present study investigated the effect of Cola nitida infusion on the expression of key genes involved in insulin signaling vis-à-vis Insulin receptor substrate 1 (IRS-1), tumor protein P53 gene, glucose transporter type 4 (GLUT4), phosphoinositide 3-kinases (PI3K) and B-cell lymphoma-2 (BCL2) in skeletal muscles of type 2 diabetic (T2D) rats.

METHODS

Type 2 diabetic rats were administered C. nitida infusion at low and high doses (150 and 300 mg/kg bodyweight, respectively), while a high dose of the infusion was also administered to a normal toxicological group. Metformin served as the standard antidiabetic drug. The rats were sacrificed at the end of the experimental period. Their psoas muscles were harvested and assayed for the expressions of IRS1, p53, GLUT4, PI3K and BCL2. The studied genes were further subjected to enrichment analysis using the ShinyGO 0.76 online software.

RESULTS

Induction of T2D upregulated the expressions of IRS-1, p53, PI3K and BCL2 in psoas muscles, while concomitantly downregulating GLUT4 expression. These expressions were significantly reversed in type 2 diabetic rats treated with C. nitida infusion, and the results were statistically significant compared to metformin. Gene enrichment analysis revealed that the genes were linked to intrinsic pathways and biological processes involved in insulin resistance. The infusion further improved muscle glucose uptake, ex vivo. Molecular docking and molecular dynamics stimulation of C. nitida infusion phytoconstituents, caffeine and theobromine with IRS-1, p53, GLUT4, PI3K and BCL2 revealed a strong binding affinity as evident by the RMSD and RMSF values.

CONCLUSION

These results indicate the potentials of C. nitida infusion to improve glucose homeostasis in skeletal muscles of type 2 diabetic rats.

Association between systemic immune-inflammatory index and diabetes mellitus: mediation analysis involving obesity indicators in the NHANES

Background

Inflammation and obesity have been widely recognized to play a key role in Diabetes mellitus (DM), and there exists a complex interplay between them. We aimed to clarify the relationship between inflammation and DM, as well as the mediating role of obesity in the relationship.

Methods

Based on the National Health and Nutrition Examination Survey (NHANES) 2005-2018. Univariate analyses of continuous and categorical variables were performed using t-test, linear regression, and χ2 test, respectively. Logistic regression was used to analyze the relationship between Systemic Immune-Inflammatory Index (SII) or natural logarithm (Ln)-SII and DM in three different models. Mediation analysis was used to determine whether four obesity indicators, including body mass index (BMI), waist circumference (WC), visceral adiposity index (VAI) and lipid accumulation product index (LAP), mediated the relationship between SII and DM.

Results

A total of 9,301 participants were included, and the levels of SII and obesity indicators (BMI, WC, LAP, and VAI) were higher in individuals with DM (p < 0.001). In all three models, SII and Ln-SII demonstrated a positive correlation with the risk of DM and a significant dose-response relationship was found (p-trend <0.05). Furthermore, BMI and WC were associated with SII and the risk of DM in all three models (p < 0.001). Mediation analysis showed that BMI and WC mediated the relationship between SII with DM, as well as Ln-SII and DM, with respective mediation proportions of 9.34% and 12.14% for SII and 10.23% and 13.67% for Ln-SII (p < 0.001).

Conclusion

Our findings suggest that increased SII levels were associated with a higher risk of DM, and BMI and WC played a critical mediating role in the relationship between SII and DM.

Effect of garlic on the components of metabolic syndrome: A systematic review and meta-analysis of randomized controlled trials

ETHNOPHARMACOLOGICAL RELEVANCE

Metabolic diseases are the major causes of macrovascular and microvascular complications which lead to morbidity and mortality. Traditionally, garlic has been used as food and medicine for more than 5000 years. However, efficacy studies have shown conflicting results regarding the garlic effect.

AIM OF THE STUDY

This study aims to evaluate the efficacy of garlic on the components of metabolic syndrome (MetS) in metabolic disease patients.

MATERIALS AND METHODS

This study was a systematic review and meta-analysis of randomized controlled trials (RCTs). Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL), and Google scholar were searched till December 25, 2021 for identifying the relevant studies that have shown the effects of garlic on components of metabolic syndrome in metabolic disease patients. The mean difference with 95% CI was calculated using fixed-effect or random-effect models.

RESULTS

The effect of garlic has shown significant changes on waist circumference (p-value= <0.0001), total cholesterol (p < 0.0001), low density lipoprotein (p = 0.01), high density lipoprotein (p < 0.00001), triglycerides (p < 0.00001), systolic blood pressure (p < 0.00001), diastolic blood pressure (p < 0.00001), glucose (p < 0.00001), Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) (p = 0.04), C-reactive protein (p < 0.00001), tumor necrosis factor (TNF)-α (p = 0.002), interleukin (IL)-6 (p = 0.0001). Subgroup analysis has shown the favorable effects of garlic in metabolic disease patients.

CONCLUSION

Our meta-analysis results confirm the findings that garlic could be useful as an anti-hyperlipidemic, anti-hyperglycemic, anti-hypertensive and anti-inflammatory drug.

Prognostic value of insulin resistance in patients with female reproductive system malignancies: A multicenter cohort study

BACKGROUND

Insulin resistance (IR) and systemic inflammation are common in patients with cancer and are associated with poor prognosis. Few studies have reported IR in female reproductive system malignancies. This study investigated the prognostic value of IR and systemic inflammation in this population.

METHODS

A prospective multicenter real-world cohort study involving 571 patients diagnosed with female reproductive system malignancies was conducted. Lipid ratios (low-density lipoprotein-cholesterol/high-density lipoprotein-cholesterol [LHR], total cholesterol/HDL-cholesterol [TCHR], triglyceride/HDL-cholesterol [TGHR], fasting triglyceride/glucose [TyG]) were used to reflect IR. Optimal cut-off values were determined using maximally selected rank statistics. The Kaplan-Meier and Cox regression were used to calculate the hazard ratios for overall survival.

RESULTS

Over half (55.90%) of the 571 patients with female reproductive system malignancies (mean age: 52 years) had cervical cancer. Both IR and inflammation were negatively correlated with overall survival in female reproductive system cancer patients. Multivariate survival analysis showed that patients with high LHR (hazard ratio [HR]: 1.51, 95% confidence interval [CI]: 1.01-2.25, p = .046), high TCHR (HR: 1.90, 95% CI:1.22-2.95, p = .005), high TGHR (HR: 1.66, 95% CI:1.17-2.36, p = .004), high TyG (HR: 1.64, 95% CI:1.13-2.40, p = .010), high neutrophil lymphocyte ratio (NLR, HR: 2.03, 95% CI:1.44-2.86, p = .004) were significantly associated with worse prognosis. By calculating the concordance index of the four IR surrogate indicators, TyG was the most valuable indicator for the prognosis of patients with malignant tumors of the female reproductive system. High TyG combined with high NLR had improved prognostic value (HR: 3.22, 95% CI: 1.97-5.26, p < .001).

CONCLUSIONS

IR can be used as an independent predictor of prognosis in the female reproductive system malignancy population regardless of the IR substitution index. The combination of TyG and NLR could better predict the prognostic outcomes of women with breast cancer.

Multiple novel functions of circular RNAs in diabetes mellitus

Circular RNAs (circRNAs), as an emerging group of non-coding RNAs (ncRNAs), have received the attention given evidence indicating that these novel ncRNAs are implicated in various biological processes. Due to the absence of 5' and 3' ends in circ-RNAs, their two ends are covalently bonded together, and they are synthesised from pre-mRNAs in a process called back-splicing, which makes them more stable than linear RNAs. There is accumulating evidence showing that circRNAs play a critical role in the pathogenesis of diabetes mellitus (DM). Moreover, it has been indicated that dysregulation of circRNAs has made them promising diagnostic biomarkers for the detection of DM. Recently, increasing attention has been paid to investigate the mechanisms underlying the DM process. It has been demonstrated that there is a strong correlation between the expression of circRNAs and DM. Hence, our aim is to discuss the crosstalk between circRNAs and DM and its complications.

Irisin suppresses pancreatic β cell pyroptosis in T2DM by inhibiting the NLRP3-GSDMD pathway and activating the Nrf2-TrX/TXNIP signaling axis

BACKGROUND

Irisin plays a key role in metabolic diseases, including type 2 diabetes mellitus (T2DM). However, the mechanism underlying the link between irisin and the development of T2DM, particularly in pancreatic islet β-cells, remains unknown.

METHODS

In vitro, Min6 cells were treated with high glucose (HG) to generate T2DM cell models. GSDMD-N staining, Western blotting assays, and ELISA were performed to measure the expression levels of GSDMD, caspase 1, IL-1β, and IL-18. Next, the NLRP3 stimulator, ATP, was used to assess the effect of irisin on NLRP3 inflammasome. To evaluate the function of the Nrf2-TrX/TXNIP signaling axis, the Nrf2 inhibitor ML385 was used. For in vivo assessment, we first established T2DM model mice. Then, hematoxylin and eosin (H&E) staining was performed to observe the islet morphology, and the immunofluorescence technique was used to examine the mass of α and β cells. To confirm the role of the Nrf2-TrX/TXNIP signaling axis, ML385 was injected into the mice. Immunofluorescence of Nrf2, caspase 1, and GSDMD was detected in the islet cells of the model mice to verify the results.

RESULTS

We found that irisin treatment significantly decreased the expression of GSDMD-N (P31) and cleaved caspase-1 (p20), decreased caspase1 activity, and inhibited the secretion of IL-1β and IL-18 in HG-treated Min6 cells. We also found that irisin inhibited oxidative stress and NLRP3 expression by activating the Nrf2-TrX/TXNIP signaling axis. Additionally, in the T2DM model mice, irisin enhanced the function of islet cells, decreased insulin resistance, and preserved the morphology of pancreatic islets.

CONCLUSION

We showed in this study that irisin can be used for treating pyroptosis in HG-induced islet β-cells and T2DM model mice. We also found that irisin inhibits pyroptosis and oxidative stress by inhibiting the NLRP3-GSDMD pathway and activating the Nrf2-TrX/TXNIP signaling axis.

Increased Levels of Caspase-1 and IL-1β Among Adults With Persistent Immune Activation After 12 Years of Suppressive Antiretroviral Therapy in the Infectious Diseases Institute HIV Treatment Cohort

Background

We sought evidence of activated pyroptosis and the inflammasome pathways among human immunodeficiency virus (HIV)-infected adults after 12 years of suppressive antiretroviral therapy (ART) and persistent immune activation in the Infectious Diseases Institute HIV treatment cohort in Uganda.

Methods

In a cross-sectional study, using peripheral blood mononuclear cells of HIV-infected individuals with high and low immune activation (CD4/CD8+CD38+HLA-DR+ cells) relative to HIV-negative reference group, caspase-1 expression was measured using flow cytometry and plasma interleukin 18 and interleukin 1β (IL-1β) levels using enzyme-linked immunosorbent assay.

Results

There was higher expression of caspase-1 by CD4 T cells of ART-treated individuals with high immune activation relative to those with lower immune activation (P = .04). Similarly, plasma levels of IL-1β were higher among ART-treated individuals with high immune activation levels relative to those with low immune activation levels (P = .009). We observed a low positive correlation between caspase-1 expression by CD4/CD8 T cells and immune activation levels (r= 0.497 and r= 0.329, respectively).

Conclusions

Caspase-1 and IL-1β were high among individuals with high immune activation despite 12 years of suppressive ART. There is a need to further understand the role of persistent abortive infection and the latent HIV reservoir characteristics as drivers of persistent activation and inflammation and to subsequently intervene to prevent the complications of chronic immune activation during long-term ART.

Resveratrol as a potential protective compound against skeletal muscle insulin resistance

The increasing prevalence of type 2 diabetes has become a major global problem. Insulin resistance has a central role in pathophysiology of type 2 diabetes. Skeletal muscle is responsible for the disposal of most of the glucose under conditions of insulin stimulation, and insulin resistance in skeletal muscle causes dysregulation of glucose homeostasis in the whole body. Despite the current pharmaceutical and non-pharmacological treatment strategies to combat diabetes, there is still a need for new therapeutic agents due to the limitations of the therapeutic agents. Meanwhile, plant polyphenols have attracted the attention of researchers for their use in the treatment of diabetes and have gained popularity. Resveratrol, a stilbenoid polyphenol, exists in various plant sources, and a growing body of evidence suggests its beneficial properties, including antidiabetic activities. The present review aimed to provide a summary of the role of resveratrol in insulin resistance in skeletal muscle and its related mechanisms. To achieve the objectives, by searching the PubMed, Scopus and Web of Science databases, we have summarized the results of all cell culture, animal, and human studies that have investigated the effects of resveratrol in different models on insulin resistance in skeletal muscle.

The Impact of Taurine on Obesity-Induced Diabetes Mellitus: Mechanisms Underlying Its Effect

This review explores the potential benefits of taurine in ameliorating the metabolic disorders of obesity and type 2 diabetes (T2D), highlighting the factors that bridge these associations. Relevant articles and studies were reviewed to conduct a comprehensive analysis of the relationship between obesity and the development of T2D and the effect of taurine on those conditions. The loss of normal β-cell function and development of T2D are associated with obesity-derived insulin resistance. The occurrence of diabetes has been linked to the low bioavailability of taurine, which plays critical roles in normal β-cell function, anti-oxidation, and anti-inflammation. The relationships among obesity, insulin resistance, β-cell dysfunction, and T2D are complex and intertwined. Taurine may play a role in ameliorating these metabolic disorders through different pathways, but further research is needed to fully understand its effects and potential as a therapeutic intervention.

Obesity and prostate cancer - microenvironmental roles of adipose tissue

Obesity is known to have important roles in driving prostate cancer aggressiveness and increased mortality. Multiple mechanisms have been postulated for these clinical observations, including effects of diet and lifestyle, systemic changes in energy balance and hormonal regulation and activation of signalling by growth factors and cytokines and other components of the immune system. Over the past decade, research on obesity has shifted towards investigating the role of peri-prostatic white adipose tissue as an important source of locally produced factors that stimulate prostate cancer progression. Cells that comprise white adipose tissue, the adipocytes and their progenitor adipose stromal cells (ASCs), which proliferate to accommodate white adipose tissue expansion in obesity, have been identified as important drivers of obesity-associated cancer progression. Accumulating evidence suggests that adipocytes are a source of lipids that are used by adjacent prostate cancer cells. However, results of preclinical studies indicate that ASCs promote tumour growth by remodelling extracellular matrix and supporting neovascularization, contributing to the recruitment of immunosuppressive cells, and inducing epithelial-mesenchymal transition through paracrine signalling. Because epithelial-mesenchymal transition is associated with cancer chemotherapy resistance and metastasis, ASCs are considered to be potential targets of therapies that could be developed to suppress cancer aggressiveness in patients with obesity.

FAM76B regulates NF-κB-mediated inflammatory pathway by influencing the translocation of hnRNPA2B1

FAM76B has been reported to be a nuclear speckle-localized protein with unknown function. In this study, FAM76B was first demonstrated to inhibit the NF-κB-mediated inflammatory pathway by affecting the translocation of hnRNPA2B1 in vitro. We further showed that FAM76B suppressed inflammation in vivo using a traumatic brain injury (TBI) mouse model. Lastly, FAM76B was shown to interact with hnRNPA2B1 in human tissues taken from patients with acute, organizing, and chronic TBI, and with different neurodegenerative diseases. The results suggested that FAM76B mediated neuroinflammation via influencing the translocation of hnRNPA2B1 in vivo during TBI repair and neurodegenerative diseases. In summary, we for the first time demonstrated the role of FAM76B in regulating inflammation and further showed that FAM76B could regulate the NF-κB-mediated inflammatory pathway by affecting hnRNPA2B1 translocation, which provides new information for studying the mechanism of inflammation regulation.

The inhibition of FKBP5 protects β-cell survival under inflammation stress via AKT/FOXO1 signaling

The FK506-binding protein 51 (FKBP51, encoded by FKBP5 gene) has emerged as a critical regulator of mammalian endocrine stress responses and as a potential pharmacological target for metabolic disorders, including type 2 diabetes (T2D). However, in β cells, which secrete the only glucose-lowering hormone-insulin, the expression and function of FKBP5 has not been documented. Here, using human pancreatic tissue and primary human islets, we demonstrated the abundant expression of FKBP5 in β cells, which displayed an responsive induction upon acute inflammatory stress mimicked by in vitro treatment with a cocktail of inflammatory cytokines (IL-1β, IFN-γ, and TNF-α). To explore its function, siRNAs targeting FKBP5 and pharmacological inhibitor SAFit2 were applied both in clonal NIT-1 cells and primary human/mice islets. We found that FKBP5 inhibition promoted β-cell survival, improved insulin secretion, and upregulated β-cell functional gene expressions (MAFA and NKX6.1) in acute-inflammation stressed β cells. In primary human and mice islets, which constitutively suffer from inflammation stress during isolation and culture, FKBP5 inhibition also presented decent performance in improving islet function, in accordance with its protective effect against inflammation. Molecular studies found that FKBP5 is an important regulator for FOXO1 phosphorylation at Serine 256, and silencing of FOXO1 abrogated the protective effect of FKBP5 inhibition, suggesting that it is the key downstream effector of FKBP5 in β cells. At last, in situ detection of FKBP5 protein expression on human and mice pancreases revealed a reduction of FKBP5 expression in β cells in human T2D patients, as well as T2D mice model (db/db), which may indicate a FKBP5-inhibition-mediated pro-survival mechanism against the complex stresses in T2D milieus.

The association between adherence to diet quality index and cardiometabolic risk factors in overweight and obese women: a cross-sectional study

Background

Obesity and overweight status increase the risk of cardiovascular disease. Diet quality can also predict the risk of cardiovascular diseases in obese and overweight patients. Therefore, in this study, we sought to examine the relationship between diet quality index (DQI) and cardiometabolic risk factors in obese and overweight women.

Method

A cross-sectional study was conducted on 197 Iranian women with a Body Mass Index (BMI) > 25, 18-48 years, and recruited from 20 Tehran Health Centers. Nutrition intake and DQI were assessed using a 147-item semi-quantitative food frequency questionnaire (FFQ). Additionally, anthropometric measurements, body composition, biochemical evaluations, and cardiometabolic risk factors were evaluated.

Results

There was an association between DQI and waist-to-hip ratio (WHR), atherogenic index of plasma (AIP), and CHOLINDEX in obese women, after adjusting for potential confounders. Whereas, there were no significant associations of the tertiles of DQI compared with the first tertile in other cardiometabolic risk factors, before and after adjustment.

Conclusion

This study provides evidence that dietary intake and DQI are associated with cardiometabolic risk factors and that dietary modification may be a predictor for reducing WHR, AIP, and CHOLINDEX. However, more research is needed to develop a DQI that reflects changes in cardiometabolic risk factors by considering women's eating habits and patterns.

Host insulin resistance caused by Porphyromonas gingivalis-review of recent progresses

Porphyromonas gingivalis (P. gingivalis) is a Gram-negative oral anaerobic bacterium that plays a key role in the pathogenesis of periodontitis. P. gingivalis expresses a variety of virulence factors that disrupt innate and adaptive immunity, allowing P. gingivalis to survive and multiply in the host and destroy periodontal tissue. In addition to periodontal disease, P.gingivalis is also associated with systemic diseases, of which insulin resistance is an important pathological basis. P. gingivalis causes a systemic inflammatory response, disrupts insulin signaling pathways, induces pancreatic β-cell hypofunction and reduced numbers, and causes decreased insulin sensitivity leading to insulin resistance (IR). In this paper, we systematically review the studies on the mechanism of insulin resistance induced by P. gingivalis, discuss the association between P. gingivalis and systemic diseases based on insulin resistance, and finally propose relevant therapeutic approaches. Overall, through a systematic review of the mechanisms related to systemic diseases caused by P. gingivalis through insulin resistance, we hope to provide new insights for future basic research and clinical interventions for related systemic diseases.

Enhancing de novo ceramide synthesis induced by bisphenol A exposure aggravates metabolic derangement during obesity

OBJECTIVE

Exposure to bisphenol A (BPA) has been shown to increase the prevalence of obesity and its related insulin resistance (IR). Ceramide is a sphingolipid known to facilitate the production of proinflammatory cytokines and subsequently exacerbate inflammation and IR during the progression of obesity. Here, we investigated the effects of BPA exposure on ceramide de novo synthesis and whether increased ceramides aggravate adipose tissue (AT) inflammation and obesity-related IR.

METHODS

A population-based case-control study was conducted to explore the relationship between BPA exposure and IR and the potential role of ceramide in AT in obesity. Next, we used mice reared on a normal chow diet (NCD) or a high-fat diet (HFD) to verify the results from the population study and then investigated the role of ceramides in low-level BPA exposure with HFD-induced IR and AT inflammation in mice treated with or without myriocin (an inhibitor of the rate-limiting enzyme in de novo ceramide synthesis).

RESULTS

BPA levels are higher in obese individuals and are significantly associated with AT inflammation and IR. Specific subtypes of ceramides mediated the associations between BPA and obesity, obesity-related IR and AT inflammation in the obesity group. In animal experiments, BPA exposure facilitated ceramide accumulation in AT, activated PKCζ, promoted AT inflammation, increased the expression and secretion of proinflammatory cytokines via the JNK/NF-κB pathway, and lowered insulin sensitivity by disrupting IRS1-PI3K-AKT signaling in mice fed a HFD. Myriocin suppressed BPA-induced AT inflammation and IR.

CONCLUSION

These findings indicate that BPA aggravates obesity-induced IR, which is partly via increased de novo synthesis of ceramides and subsequent promotion of AT inflammation. Ceramide synthesis could be a potential target for the prevention of environmental BPA exposure-related metabolic diseases.

The Link between Diabetes, Pancreatic Tumors, and miRNAs-New Players for Diagnosis and Therapy?

Despite significant progress in medicine, pancreatic cancer is one of the most tardily diagnosed cancer and is consequently associated with a poor prognosis and a low survival rate. The asymptomatic clinical picture and the lack of relevant diagnostic markers for the early stages of pancreatic cancer are believed to be the major constraints behind an accurate diagnosis of this disease. Furthermore, underlying mechanisms of pancreatic cancer development are still poorly recognized. It is well accepted that diabetes increases the risk of pancreatic cancer development, however the precise mechanisms are weakly investigated. Recent studies are focused on microRNAs as a causative factor of pancreatic cancer. This review aims to provide an overview of the current knowledge of pancreatic cancer and diabetes-associated microRNAs, and their potential in diagnosis and therapy. miR-96, miR-124, miR-21, and miR-10a were identified as promising biomarkers for early pancreatic cancer prediction. miR-26a, miR-101, and miR-200b carry therapeutic potential, as they not only regulate significant biological pathways, including the TGF-β and PI3K/AKT, but their re-expression contributes to the improvement of the prognosis by reducing invasiveness or chemoresistance. In diabetes, there are also changes in the expression of microRNAs, such as in miR-145, miR-29c, and miR-143. These microRNAs are involved, among others, in insulin signaling, including IRS-1 and AKT (miR-145), glucose homeostasis (hsa-miR-21), and glucose reuptake and gluconeogenesis (miR-29c). Although, changes in the expression of the same microRNAs are observed in both pancreatic cancer and diabetes, they exert different molecular effects. For example, miR-181a is upregulated in both pancreatic cancer and diabetes mellitus, but in diabetes it contributes to insulin resistance, whereas in pancreatic cancer it promotes tumor cell migration, respectively. To conclude, dysregulated microRNAs in diabetes affect crucial cellular processes that are involved in pancreatic cancer development and progression.

New Insight on In Vitro Biological Activities of Sulfated Polysaccharides from Ulvophyte Green Algae

Green algae are natural bioresources that have excellent bioactive potential, partly due to sulfated polysaccharides (SPs) which are still rarely explored for their biological activities. There is currently an urgent need for studies exploring the anticancer biological activity of SPs extracted from two Indonesian ulvophyte green algae: the sulfated polysaccharide of Caulerpa racemosa (SPCr) and the sulfated polysaccharide of Caulerpa lentillifera (SPCl). The method of isolating SPs and their assessment of biological activities in this study were based on previous and similar studies. The highest yield sulfate/total sugar ratio was presented by SPCr than that of SPCl. Overall, SPCr exhibits a strong antioxidant activity, as indicated by smaller EC₅₀ values obtained from a series of antioxidant activity assays compared to the EC₅₀ values of Trolox (control). As an anti-obesity and antidiabetic, the overall EC₅₀ value of both SPs was close to the EC₅₀ of the positive control (orlistat and acarbose). Even more interesting was that SPCl displayed wide-ranging anticancer effects on colorectal, hepatoma, breast cancer cell lines, and leukemia. Finally, this study reveals new insights in that SPs from two Indonesian green algae have the potential to be promising nutraceuticals as novel antioxidative actors, and to be able to fight obesity, diabetes, and even cancer.

Posttranscriptional regulation of the prostaglandin E receptor spliced-isoform EP3-γ and its implication in pancreatic β-cell failure

In Type 2 diabetes (T2D), elevated lipid levels have been suggested to contribute to insulin resistance and β-cell dysfunction. We previously reported that the expression of the PGE2 receptor EP3 is elevated in islets of T2D individuals and is preferentially stimulated by palmitate, leading to β-cell failure. The mouse EP3 receptor generates three isoforms by alternative splicing which differ in their C-terminal domain and are referred to as mEP3α, mEP3β, and mEP3γ. We bring evidence that the expression of the mEP3γ isoform is elevated in islets of diabetic db/db mice and is selectively upregulated by palmitate. Specific knockdown of the mEP3γ isoform restores the expression of β-cell-specific genes and rescues MIN6 cells from palmitate-induced dysfunction and apoptosis. This study indicates that palmitate stimulates the expression of the mEP3γ by a posttranscriptional mechanism, compared to the other spliced isoforms, and that the de novo synthesized ceramide plays an important role in FFA-induced mEP3γ expression in β-cells. Moreover, induced levels of mEP3γ mRNA by palmitate or ceramide depend on p38 MAPK activation. Our findings suggest that mEP3γ gene expression is regulated at the posttranscriptional level and defines the EP3 signaling axis as an important pathway mediating β-cell-impaired function and demise.

Corchorus olitorius extract exhibit anti-hyperglycemic and anti-inflammatory properties in rodent models of obesity and diabetes mellitus

Obesity and type 2 diabetes (T2D) are chronic conditions with detrimental impacts on the overall health of individuals. Presently, the use of pharmacological agents in obesity and T2D offers limited benefits and pose side effects. This warrant studies on remedies that are less toxic and inexpensive while effective in ameliorating secondary complications in obesity and T2D. Plant-based remedies have been explored increasingly due to their remarkable properties and safety profile. We searched for pre-clinical evidence published from inception until 2023 on PubMed, Scopus, Google, and Semantic scholar on Corchorus olitorius (C. olitorius) in both obesity and T2D. Our focus was to understand the beneficial impact of this plant-based remedy on basic glycemic, lipid, inflammatory, and biomarkers of oxidative stress. The evidence gathered in this review suggests that C. olitorius treatment may significantly reduce blood glucose, body weight, total cholesterol, triglycerides, and low-density lipoprotein (LDL) in concomitant with increasing high-density lipoprotein-cholesterol (HDL-c) in rodent models of obesity and T2D. Interestingly, this effect was consistent with the reduction of malonaldehyde, superoxide dismutase and catalases, tumor necrosis factor-alpha, interleukins, and leptin. Some of the mechanisms by which C. olitorius reduces blood glucose levels is through stimulation of insulin secretion, increasing β-cell proliferation, thus promoting insulin sensitivity; the process which is mediated by ascorbic acid present in this plant. C. olitorius anti-hyperlipidemia is attributable to the content of ferulic acid found in this plant, which inhibits 3-Hydroxy-3-methyl glutaryl coenzyme A (HMG-CoA) reductase inhibitors and thus results in reduced synthesis of cholesterol and increased hepatic LDL-c receptor expression, respectively. The present review provides extensive knowledge and further highlights the potential benefits of C. olitorius on basic metabolic parameters, lipid profile, inflammation, and oxidative stress in rodent models of obesity and T2D.

Circadian-mediated regulation of cardiometabolic disorders and aging with time-restricted feeding

Circadian rhythms are present throughout biology, from the molecular level to complex behaviors such as eating and sleeping. They are driven by molecular clocks within cells, and different tissues can have unique rhythms. Circadian disruption can trigger obesity and other common metabolic disorders such as aging, diabetes, and cardiovascular disease, and circadian genes control metabolism. At an organismal level, feeding and fasting rhythms are key drivers of circadian rhythms. This underscores the bidirectional relationship between metabolism and circadian rhythms, and many metabolic disorders have circadian disruption or misalignment. Therefore, studying circadian rhythms may offer new avenues for understanding the etiology and management of obesity. This review describes how circadian rhythm dysregulation is linked with cardiometabolic disorders and how the lifestyle intervention of time-restricted feeding (TRF) regulates them. TRF reinforces feeding-fasting rhythms without reducing caloric intake and ameliorates metabolic disorders such as obesity and associated cardiac dysfunction, along with reducing inflammation. TRF optimizes the expression of genes and pathways related to normal metabolic function, linking metabolism with TRF's benefits and demonstrating the molecular link between metabolic disorders and circadian rhythms. Thus, TRF has tremendous therapeutic potential that could be easily adopted to reduce obesity-linked dysfunction and cardiometabolic disorders.

ATF5 is a regulator of ER stress and β-cell apoptosis in different mouse models of genetic- and diet-induced obesity and diabetes mellitus

Endoplasmic reticulum (ER) stress is closely associated with type 2 diabetes (T2D). Activating transcription factor 5 (ATF5) is a member of the ATF/cAMP response element binding protein (CREB) family whose levels are increased upon stress in pancreatic islets from mice. Intriguingly, ATF5 deficiency has been shown to contribute to increased ER stress and apoptosis in mouse islet micro-organs. We hypothesized that either deficiency or overexpression of ATF5 is equally deleterious for pancreatic islets in terms of ER stress and apoptosis. To test this, we used a number of in vitro and in vivo models whereby ATF5 levels were overexpressed. We also determined the regulation of ATF5 in the context of metabolic derangements by using various mouse models of obesity and T2D. Our in vitro results show that ATF5 overexpression promoted palmitic acid (PA)-induced lipotoxic apoptosis. In vivo, global ATF5 overexpression in mice was lethal and pancreas-specific ATF5 overexpressing mice exhibit increased β-cell apoptosis. Interestingly, ATF5 is downregulated in all mouse models of severe obesity and T2D used in the current study. In conclusion, a tight control on ATF5 levels might be considered when developing novel agents targeting ATF5 for prevention and treatment of metabolic diseases.

An Original Asteraceae Based Infused Drink Prevents Metabolic Syndrome in Fructose-Rat Model

Metabolic syndrome (METS) is a complex disorder that predisposes an affected person to an increased risk of diabetes and cardiovascular disease. Bitter Asteraceae plants contain several compounds active against METS that can be used as an alternative preventive therapy. Our previous work showed that a natural chicory extract (NCRAE) containing chicoric acid (CRA) and chlorogenic acid (CGA) in a molar ratio of 70/30 exhibited an antioxidant, insulin sensitization and anti-hyperglycemic effect. The present study was designed to evaluate the preventive effects of an NCRAE-like extract against METS in a complementary natural pharmacotherapeutic approach. An original Asteraceae infused drink containing the NCRAE CRA/CGA molecular ratio equivalent was prepared from dandelion (Taraxacum officinale L.) and burdock (Arctium lappa L.). The anti-METS effect of this drink was evaluated on the fructose-rat model for 8 weeks. Body weight, blood biochemistry, hepatic glucose-6-phosphatase, arterial blood pressure glucose and insulin tolerance were evaluated after 8 weeks. Our results show that daily oral intake of the Asteraceae infused drink led to a reduction of body weight gain, hyperglycemia, hypertriglyceridemia, insulin resistance and hypertension. Moreover, rat-by-rat analysis of the insulinemia measures revealed two types of responders. One sub-group of subjects demonstrated normal insulinemia and the other subgroup demonstrated hyperinsulinemia. This hyperinsulinemia, associated with the inhibition of the glucose-6-phosphatase activity in the liver tissue, may suggest an insulin release caused by CGA. The present study suggests that this original infusion of dandelion leaves and burdock roots may be used as an adjuvant therapy to prevent metabolic syndrome.

Gut Microbiota and Time-Restricted Feeding/Eating: A Targeted Biomarker and Approach in Precision Nutrition

Each individual has a unique gut microbiota; therefore, the genes in our microbiome outnumber the genes in our genome by about 150 to 1. Perturbation in host nutritional status influences gut microbiome composition and vice versa. The gut microbiome can help in producing vitamins, hormones, and other active metabolites that support the immune system; harvest energy from food; aid in digestion; protect against pathogens; improve gut transit and function; send signals to the brain and other organs; oscillate the circadian rhythm; and coordinate with the host metabolism through multiple cellular pathways. Gut microbiota can be influenced by host genetics, medications, diet, and lifestyle factors from preterm to aging. Aligning with precision nutrition, identifying a personalized microbiome mandates the provision of the right nutrients at the right time to the right patient. Thus, before prescribing a personalized treatment, it is crucial to monitor and count the gut flora as a focused biomarker. Many nutritional approaches that have been developed help in maintaining and restoring an optimal microbiome such as specific diet therapy, nutrition interventions, and customized eating patterns. One of these approaches is time-restricted feeding/eating (TRF/E), a type of intermittent fasting (IF) in which a subject abstains from food intake for a specific time window. Such a dietary modification might alter and restore the gut microbiome for proper alignment of cellular and molecular pathways throughout the lifespan. In this review, we have highlighted that the gut microbiota would be a targeted biomarker and TRF/E would be a targeted approach for restoring the gut-microbiome-associated molecular pathways such as hormonal signaling, the circadian system, metabolic regulators, neural responses, and immune-inflammatory pathways. Consequently, modulation of the gut microbiota through TRF/E could contribute to proper utilization and availability of the nutrients and in this way confer protection against diseases for harnessing personalized nutrition approaches to improve human health.

Sustained air pollution exposures, fasting plasma glucose, glycated haemoglobin, prevalence and incidence of diabetes: a nationwide study in China

BACKGROUND

Evidence remains limited and inconsistent for the associations between sustained air pollution exposures and diabetes development. This study aimed to determine the potential effects of particulate matter with a diameter of ≤10 micrometres (PM10), particulate matter with a diameter of ≤2.5 micrometres (PM2.5) and nitrogen dioxide (NO2) on alterations of fasting plasma glucose (FPG), glycated haemoglobin (HbA1c), in particular, on prevalence and incidence of diabetes.

METHODS

Cross-sectional analyses were conducted based on 9628 participants aged ≥45 years from the baseline survey (2011) of the China Health and Retirement Longitudinal Study (CHARLS), whereas cohort analyses were based on 3510 individuals without diabetes at baseline in the third survey (2015). Residences of participants were geocoded and the air pollution exposures were estimated using a satellite-based spatiotemporal model. Linear, logistic and modified Poisson regression models, adjusting for multiple confounders, were applied to assess the associations between air pollution and FPG, HbA1c, prevalence and incidence of diabetes, respectively.

RESULTS

Associations between PM10, PM2.5 and increased levels of FPG and HbA1c were identified. The levels of FPG and HbA1c increased by 0.025 mmol/L (95% CI: 0.007, 0.044) and 0.011 mmol/L (95% CI: 0.002, 0.019), respectively, for a 10-μg/m3 increase in PM10, and the levels of FPG and HbA1c increased by 0.061 mmol/L (95% CI: 0.028, 0.096) and 0.016 mmol/L (95% CI: 0.000, 0.031), respectively, for a 10-μg/m3 increase in PM2.5. There were also positive associations between diabetes prevalence and PM2.5 and PM10. In the cohort analyses, PM10, PM2.5 and NO2 were associated with a higher incidence of diabetes.

CONCLUSION

Air pollution was allied to diabetes development in elderly Chinese populations. Considering the impact of the dramatic increase in the incidence and prevalence of diabetes in China, interventions to improve air quality are urgently needed.

Exenatide regulates Th17/Treg balance via PI3K/Akt/FoxO1 pathway in db/db mice

BACKGROUND

The T helper 17 (Th17)/T regulatory (Treg) cell imbalance is involved in the course of obesity and type 2 diabetes mellitus (T2DM). In the current study, the exact role of glucagon-like peptide-1 receptor agonist (GLP-1RA) exenatide on regulating the Th17/Treg balance and the underlying molecular mechanisms are investigated in obese diabetic mice model.

METHODS

Metabolic parameters were monitored in db/db mice treated with/without exenatide during 8-week study period. The frequencies of Th17 and Treg cells from peripheral blood and pancreas in db/db mice were assessed. The phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/Forkhead box O1 (FoxO1) pathway in Th17 and Treg cells from the spleens of male C57BL/6J mice was detected by western blotting. In addition, the expression of glucagon-like peptide-1 receptor (GLP-1R) in peripheral blood mononuclear cells (PBMCs) of male C57BL/6J mice was analyzed.

RESULTS

Exenatide treatment improved β-cell function and insulitis in addition to glucose, insulin sensitivity and weight. Increased Th17 and decreased Treg cells in peripheral blood were present as diabetes progressed while exenatide corrected this imbalance. Progressive IL-17 + T cell infiltration of pancreatic islets was alleviated by exenatide intervention. In vitro study showed no significant difference in the level of GLP-1R expression in PBMCs between control and palmitate (PA) groups. In addition, PA could promote Th17 but suppress Treg differentiation along with down-regulating the phosphorylation of PI3K/Akt/FoxO1, which was reversed by exenatide intervention. FoxO1 inhibitor AS1842856 could abrogate all these effects of exenatide against lipid stress.

CONCLUSIONS

Exenatide could restore systemic Th17/Treg balance via regulating FoxO1 pathway with the progression of diabetes in db/db mice. The protection of pancreatic β-cell function may be partially mediated by inhibiting Th17 cell infiltration into pancreatic islets, and the resultant alleviation of islet inflammation.

TonEBP in Myeloid Cells Promotes Obesity-Induced Insulin Resistance and Inflammation Through Adipose Tissue Remodeling

The phenotypic and functional plasticity of adipose tissue macrophages (ATMs) during obesity plays a crucial role in orchestration of adipose and systemic inflammation. Tonicity-responsive enhancer binding protein (TonEBP) (also called NFAT5) is a stress protein that mediates cellular responses to a range of metabolic insults. Here, we show that myeloid cell-specific TonEBP depletion reduced inflammation and insulin resistance in mice with high-fat diet-induced obesity but did not affect adiposity. This phenotype was associated with a reduced accumulation and a reduced proinflammatory phenotype of metabolically activated macrophages, decreased expression of inflammatory factors related to insulin resistance, and enhanced insulin sensitivity. TonEBP expression was elevated in the ATMs of obese mice, and Sp1 was identified as a central regulator of TonEBP induction. TonEBP depletion in macrophages decreased induction of insulin resistance-related genes and promoted induction of insulin sensitivity-related genes under obesity-mimicking conditions and thereby improved insulin signaling and glucose uptake in adipocytes. mRNA expression of TonEBP in peripheral blood mononuclear cells was positively correlated with blood glucose levels in mice and humans. These findings suggest that TonEBP in macrophages promotes obesity-associated systemic insulin resistance and inflammation, and downregulation of TonEBP may induce a healthy metabolic state during obesity.

Microplastic-Contaminated Feed Interferes with Antioxidant Enzyme and Lysozyme Gene Expression of Pacific White Shrimp (Litopenaeus vannamei) Leading to Hepatopancreas Damage and Increased Mortality

Microplastic pollution can interfere with aquatic animal health and nonspecific immunity, increasing the potential for pathogen infection in crustaceans. However, the long-term effects of microplastics on crustacean immunity are less understood, especially regarding their toxicity in Pacific white shrimp (Litopenaeus vannamei). Effects of high-density polyethylene microplastics (HDPE-MPs) in feed on the mortality rate, hepatopancreas, and nonspecific immune system gene expression of Pacific white shrimp are presented. The LC₅₀ at day 28 of HDPE-MP exposure was determined as 3.074% HDPE-MP in feed. A significant upregulation of the superoxide dismutase (SOD) and glutathione peroxidase (GPx) genes was observed in shrimp that were fed with 0.1 and 0.5% of HDPE-MP; then, they were downregulated significantly, except for the SOD gene expression of shrimp fed with 0.1% of HDPE-MP. The lysozyme (LYZ) gene was upregulated significantly in shrimp that were fed with 0.5, 1, and 3% HDPE-MP for 7 days and downregulated significantly in HDPE-receiving groups for at least 14 days. Significant histopathological changes in the hepatopancreas were observed in the treatment groups. The histopathological score of each lesion was correlated with the increase in HDPE-MP concentration. This study shows that the ingestion of HDPE microplastics can alter the expression of nonspecific immune system genes and damage the hepatopancreas in Pacific white shrimp.

Aquaporin-8 overexpression is involved in vascular structure and function changes in placentas of gestational diabetes mellitus patients

To study the role and mechanism of aquaporin-8 (AQP8) in placental vascular development in gestational diabetes mellitus (GDM), hematoxylin–eosin staining and immunohistochemistry were utilized to analyze the histopathological changes in placentas in GDM patients. Transwell, CCK-8, and tube formation assays were performed to examine cell migration, proliferation, and tube formation. AQP8, vascular cell adhesion molecule 1 (VCAM-1), tumor necrosis factor alpha (TNF)-α, and vascular endothelial growth factor (VEGF)-A expression levels were investigated. Relative to the control group, the placentas in the GDM group showed morphological changes, the number of microvessels in the placental villi arterioles was significantly higher, and the area of microvessels in the arterioles of placental villi was significantly lower. The expression levels of VCAM-1, TNF-α, VEGF-A, and AQP8 in the GDM placentas and human umbilical vein endothelial cells (HUVECs) stimulated by high glucose were significantly higher than those in the control group, and AQP8 was located in placental endothelial cells. Overexpression of glucose and AQP8 inhibited tube formation, migration, and proliferation in HUVECs. High glucose levels can induce dysfunction in vascular endothelial cells and lead to pathological changes in the placental vascular structure in GDM. AQP8 overexpression in placental GDM can inhibit endothelial cell behavior, cause endothelial cell dysfunction, and further participate in the occurrence and development of GDM placental vascular lesions.

Association between vitamin D serum levels and insulin resistance assessed by HOMA-IR among non-diabetic adults in the United States: Results from NHANES 2007-2014

Insulin resistance, a pathological response to insulin hormone in insulin-dependent cells, is characterized by the presence of high glucose and insulin concentrations. The homeostasis model of insulin resistance (HOMA-IR) is one of the most used indexes to estimate insulin resistance by assessing the fasting glucose and insulin levels. An association was observed between vitamin D levels and insulin resistance, which varied in different ethnic groups, and there is some evidence that vitamin D supplementation could contribute to the improvement of insulin resistance. This study assessed the association between 25-hydroxyvitamin D (25[OH]D) concentration and HOMA-IR in American adults aged 20 years and older, without diabetes and other chronic diseases that can influence insulin resistance. The data from the National Health and Nutrition Examination Survey (NHANES) 2007–2014 were used by exploiting the free and publicly-accessible web datasets. Linear regression models were performed to evaluate the association between serum 25(OH)D concentration and HOMA-IR, and a negative association was observed, which remained significant following the adjustment for age, gender, race/ethnicity, education, body mass index (BMI), physical activity, the season of examination, current smoking, hypertension, the use of drugs which can influence insulin resistance, serum bicarbonates, triglycerides, and calcium and phosphorus levels. Only in non-Hispanic Blacks was this inverse association between vitamin D and HOMA-IR not observed in the fully adjusted model. Further studies are needed to explain the mechanisms of the observed ethnic/racial differences in the association of vitamin D levels with HOMA-IR.

Fat Intake and High Triglyceride-Glucose Index in Individuals at Cardiometabolic Risk: An Isocaloric Substitution Analyses

Insulin resistance (IR) is an important risk factor for cardiovascular diseases, and the triglyceride-glucose index (TyG index) is a potential IR biomarker. Evidence also suggests that fat intake may modulate IR status, but this relationship remains unclear. Thus, the present study aimed to analyze the relationship between the TyG index and isocaloric replacement of macronutrients, including the profile of dietary fatty acids in individuals at cardiometabolic risk.

This cross-sectional study enrolled 264 individuals at cardiometabolic risk (age 43.1 ± 16.3 years) who participated in a nutritional intervention study (ReBEC, id: RBR-5n4y2g). The baseline demographic, anthropometric, clinical, dietary, and lifestyle data were used. The TyG index was calculated using the formula ln [fasting triglycerides (mg/dL) × fasting plasma glucose (mg/dL)/2]. Multivariate nutrient density models were used to analyze isocaloric replacement of fatty acids (as 5% of energy). The chance of having a high TyG index (TyG index >8.83, median value) was decreased by 60% after replacing 5% of the energy intake of polyunsaturated fatty acid (PUFA), saturated fatty acid (SFA), and trans fatty acid (TFA) with monounsaturated fatty acid (MUFA) or PUFA and SFA with protein.

Isocaloric replacement of PUFA, SFA, and TFA with MUFA and protein was associated with lower chances of having a high TyG index. These results indicate the importance of macronutrient and dietary fat profiles in the dietary planning of individuals at cardiometabolic risk.

Early introduction of exercise prevents insulin resistance in postnatal overfed rats

Early childhood obesity increases the risk of developing metabolic diseases. We examined the early introduction of exercise in small-litter obese-induced rats (SL) on glucose metabolism in the epididymal adipose tissue (AT) and soleus muscle (SM). On day 3 post-birth, pups were divided into groups of ten or three (SL). On day 22, rats were split into sedentary (S and SLS) and exercise (E and SLE) groups. The rats swam three times/week carrying a load for 30 min. In the first week, they swam without a load; in the 2nd week, they carried a load equivalent to 2% of their body weight; from the 3rd week to the final week, they carried a 5% body load. At 85 days of age, an insulin tolerance test was performed in some rats. At 90 days of age, rats were killed, and blood was harvested for plasma glucose, cholesterol, and triacylglycerol measurements. Mesenteric, epididymal, retroperitoneal, and brown adipose tissues were removed and weighed. SM and AT were incubated in the Krebs-Ringer bicarbonate buffer, 5.5 mM glucose for 1 h with or without 10 mU/mL insulin. Comparison between the groups was performed by 3-way ANOVA followed by the Tukey post-hoc test. Sedentary, overfed rats had greater body mass, more visceral fat, lower lactate production, and insulin resistance. Early introduction of exercise reduced plasma cholesterol and contained the deposition of white adipose tissue and insulin resistance. In conclusion, the early introduction of exercise prevents the effects of obesity on glucose metabolism in adulthood in this rat model.

Saturated Fatty Acid-Induced Endoplasmic Reticulum Stress and Insulin Resistance Are Prevented by Imoxin in C2C12 Myotubes

In obesity, plasma free fatty acids (FFAs) levels are elevated due to enlarged adipose tissue mass. Saturated fatty acids can induce prolonged ER stress and insulin resistance. Double-stranded RNA-dependent Protein Kinase (PKR) is activated under stress conditions in skeletal muscle. The current study aimed to investigate the effect of imoxin (IMX), a selective PKR inhibitor, on palmitate-induced ER stress and insulin resistance in C2C12 myotubes. Cells were treated with 5 μM imoxin and exposed to 0.5 mM bovine serum albumin (BSA)-conjugated PA for 24 h. A subset of cells was stimulated with 50 nM insulin for the last 15 min. Glucose uptake was monitored and protein levels involved in ER stress and insulin signaling were measured by Western blotting. Palmitate stimulated PKR phosphorylation, which was prevented by imoxin. Moreover, imoxin reduced protein levels of ER stress-related markers including glucose-regulating protein 78 (GRP78), CCAAT-enhancer-binding protein homologous protein (CHOP), activating transcription factor 6 (ATF6) and spliced X-box binding protein 1 (XBP-1s) which were induced by palmitate. Furthermore, imoxin ameliorated palmitate-induced suppression of phospho-insulin receptor beta (p-IRβ) and Akt phosphorylation in myotubes. In addition, imoxin promoted glucose uptake in response to insulin under palmitate exposure. Furthermore, imoxin reduced phospho-c-Jun N-terminal kinase (p-JNK) induced by palmitate treatment. These findings suggest that imoxin may protect against saturated fatty acid-induced ER stress and insulin resistance in skeletal muscle, which are potentially mediated by PKR.

The impact of maternal high-fat diet on offspring neurodevelopment

A maternal high-fat diet affects offspring neurodevelopment with long-term consequences on their brain health and behavior. During the past three decades, obesity has rapidly increased in the whole human population worldwide, including women of reproductive age. It is known that maternal obesity caused by a high-fat diet may lead to neurodevelopmental disorders in their offspring, such as autism spectrum disorder, attention deficit hyperactivity disorder, anxiety, depression, and schizophrenia. A maternal high-fat diet can affect offspring neurodevelopment due to inflammatory activation of the maternal gut, adipose tissue, and placenta, mirrored by increased levels of pro-inflammatory cytokines in both maternal and fetal circulation. Furthermore, a maternal high fat diet causes gut microbial dysbiosis further contributing to increased inflammatory milieu during pregnancy and lactation, thus disturbing both prenatal and postnatal neurodevelopment of the offspring. In addition, global molecular and cellular changes in the offspring's brain may occur due to epigenetic modifications including the downregulation of brain-derived neurotrophic factor (BDNF) expression and the activation of the endocannabinoid system. These neurodevelopmental aberrations are reflected in behavioral deficits observed in animals, corresponding to behavioral phenotypes of certain neurodevelopmental disorders in humans. Here we reviewed recent findings from rodent models and from human studies to reveal potential mechanisms by which a maternal high-fat diet interferes with the neurodevelopment of the offspring.

Effects of Inflammatory Factor Expression Regulated by 12/15 Lipoxygenase on Obesity-Related Nephropathy

Background: It has been demonstrated that 12/15-lipoxygenase (LO) contributes to insulin resistance by promoting beta cells’ exposure to inflammation. We investigate the mechanism by which 12/15-LO regulates the expression of inflammatory factors in obesity-related glomerular disease (ORG). Methods: Glomerular mesangial cells were treated with metabolite of 12/15-LO, and the expression of inflammatory factors was measured. Cell histones methylation in 12/15-LO related metabolic memory process were evaluated by chromatin immunoprecipitation (ChIP) assays. Wild-type (WT) and 12/15-LO knockout mice were fed a high-fat diet (HFD) to induce ORG. Results: 12(S)-HETE increased TNF-α, MCP-1, and IL-6 mRNA expression. Inhibition of 12/15-LO reduced the expression of inflammatory factors stimulated by PA or TNF-α. ChIP assays showed that 12(S)-HETE increased H3K4me modification in the TNF-α, IL-6, and MCP-1 gene promoters, and decreased H3K9me3 modification in the MCP-1 and IL-6 gene promoter. Urinary albumin excretion was greater in HFD-fed than in standard fat diet-fed mice, but both urinary protein and microalbumin amounts were lower in HFD-fed 12/15-LO knockout than in WT mice. The levels of TNF-α, IL-6, and MCP-1 in serum and renal cortex were higher in WT than in 12/15-LO knockout mice. Conclusions: 12/15-LO may regulate the expression of inflammatory factors in ORG by methylation of histones in the promoter regions of genes encoding inflammatory factors, sustaining the inflammatory phenotype of ORG.

Immediate-release tofacitinib reduces insulin resistance in non-diabetic active rheumatoid arthritis patients: A single-center retrospective study

BACKGROUND

An increased risk of insulin resistance (IR) has been identified in rheumatoid arthritis (RA), a chronic inflammatory disorder with elevated levels of pathogenic cytokines. Biologics targeting proinflammatory cytokines can control the disease and improve insulin sensitivity in RA. Although Janus kinase (JAK) signaling can regulate cytokine receptors and participate in RA pathogenesis, it remains to be elucidated whether there is a reduction of IR in such patients under JAK inhibitor (JAKi) therapy.

AIM

To study the effect of JAKi treatment on the reduction of IR in RA patients with active disease.

METHODS

A retrospective study was carried out from April 1, 2017 to March 31, 2021 in a population of non-diabetic patients with active RA who were undergoing tofacitinib (TOF) therapy with 5 mg twice-daily immediate-release formulation.

RESULTS

Fifty-six RA patients, aged 30 years to 75 years (mean ± SD: 52.3 ± 11.1) with disease activity score 28 values ranging from 4.54 to 7.37 (5.82 ± 0.74), were classified into high-IR (> 2.0) and low-IR (≤ 2.0) groups based on their baseline homeostatic model assessment (HOMA)-IR levels. They had no previous exposure to JAKi, and received TOF therapy for no less than 6 mo. In 30 patients who were naïve to biologics, after a 24-week therapeutic period, the high-IR group showed reduced HOMA-IR levels (3.331 ± 1.036 vs 2.292 ± 0.707, P < 0.001). In another 26 patients who were exposed to tumor necrosis factor-α or interleukin-6 blockers, the high-IR group, despite having achieved a decrease but with lower magnitude than in naïve patients, showed reduced HOMA-IR levels (2.924 ± 0.790 vs 2.545 ± 1.080, P = 0.018).

CONCLUSION

In this retrospective study, reduced IR was achieved in non-diabetic active RA patients following 24 wk of TOF therapy.

Effects of natural dihydrochalcones in sweet tea (Lithocarpus polystachyus) on diabetes: a systematical review and meta-analysis of animal studies

Sweet tea (Lithocarpus polystachyus Rehd.), a natural functional food highly rich in dihydrochalcones including trilobatin, phlorizin and phloretin, is reported to possess numerous biological activities especially for treating diabetes. Here, the aim of this systematical review and meta-analysis is to assess the effect of dihydrochalcones in sweet tea (DST) on diabetes and summarize their possible mechanisms. We searched in eight databases including Embase, PubMed, Cochrane, Web of Science, WanFang database, VIP database, China National Knowledge Infrastructure and China Biology Medicine from Jan 2000 to Nov 2021 and ultimately included 21 animal studies in this review. A total of 10 outcome measurements including blood lipid indexes, blood glucose, insulin resistance indicators and oxidative stress biomarkers were extracted for meta-analysis using RevMan 5.4 software. DST significantly decreased the levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), blood glucose (BG), homeostasis model assessment of insulin resistance (HOMA-IR) and malondialdehyde (MDA), and increased high-density lipoprotein cholesterol (HDL-c), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity in diabetic animal models. In summary, DST could treat diabetes by regulation of blood glucose/lipid metabolism, oxidative/carbonyl stress, inflammatory response etc.

Ginsenoside compound K inhibits obesity-induced insulin resistance by regulation of macrophage recruitment and polarization via activating PPARγ

Obesity disrupts the immune system of adipose tissue, and the activation of its macrophages constantly infiltrating adipose tissue is a crucial cause of insulin resistance induced by obesity. We previously reported for the first time in vitro that the antidiabetic effect of CK may be through the inhibition of macrophage activation and we further explored the specific mechanism in vivo. In order to clarify it, the C57BL/6J mice were fed with a high fat diet and then administered with CK orally. The related biochemical indices were detected, the inflammatory factors in serum and tissues were measured, and the related protein expression levels in insulin pathways and inflammatory signaling pathways were observed. The results showed that CK could dose-dependently reduce macrophage M1-type inflammatory factor expression in serum and adipose tissue, improve insulin resistance and glucose tolerance effectively, upregulate PPARγ expression and block TLR4/TRAF6/TAK1/NF-κB activation in obese mice. In addition, CK promoted the expression of IRS1/PI3K/AKT. Furthermore, our study showed that ginsenoside CK could improve insulin resistance by reducing inflammation through the PPARγ/NF-κB signaling pathway, which implies that ginsenoside CK may be an effective agent against obesity or early diabetes.

Role of polyphenols in combating Type 2 Diabetes and insulin resistance

Compromised carbohydrate metabolism leading to hyperglycemia is the primary metabolic disorder of non-insulin-dependent diabetes mellitus. Reformed digestion and altered absorption of carbohydrates, exhaustion of glycogen stock, enhanced gluconeogenesis and overproduced hepatic glucose, dysfunction of β-cell, resistance to insulin in peripheral tissue, and impaired insulin signaling pathways are essential reasons for hyperglycemia. Although oral anti-diabetic drugs like α-glucosidase inhibitors, sulfonylureas and insulin therapies are commonly used to manage Type 2 Diabetes (T2D) and hyperglycemia, natural compounds in diet also play a significant role in combating the effect of diabetes. Due to their vast bioavailability and anti-hyperglycemic effect with least or no side effects, polyphenolic compounds have gained wide popularity. Polyphenols such as flavonoids and tannins play a significant role in carbohydrate metabolism by inhibiting key enzymes responsible for the digestion of carbohydrates to glucose like α-glucosidase and α-amylase. Several polyphenols such as resveratrol, epigallocatechin-3-gallate (EGCG) and quercetin enhanced glucose uptake in the muscle and adipocytes by translocating GLUT4 to plasma membrane mainly by the activation of the AMP-activated protein kinase (AMPK) pathway. This review provides an insight into the protective role of polyphenols in T2D, highlighting the aspects of insulin resistance.

Research progress on the mechanism of beta-cell apoptosis in type 2 diabetes mellitus

Type 2 diabetes mellitus(T2DM) is regarded as one of the most severe chronic metabolic diseases worldwide, which poses a great threat to human safety and health. The main feature of T2DM is the deterioration of pancreatic beta-cell function. More and more studies have shown that the decline of pancreatic beta-cell function in T2DM can be attributable to beta-cell apoptosis, but the exact mechanisms of beta-cell apoptosis in T2DM are not yet fully clarified. Therefore, in this review, we will focus on the current status and progress of research on the mechanism of pancreatic beta-cell apoptosis in T2DM, to provide new ideas for T2DM treatment strategies.