mRNA expression of platelet activating factor receptor (PAFR) in peripheral blood mononuclear cells is associated with albuminuria and vascular dysfunction in patients with type 2 diabetes

Role of Platelet Activating Factor as a Mediator of Inflammatory Diseases and Preterm Delivery

Nearly 70% of preterm deliveries occur spontaneously, and the clinical pathways involved include preterm labor and preterm premature rupture of membranes. Prediction of preterm delivery is considered crucial due to the significant effects of preterm birth on health and the economy at both the personal and community levels. Although similar inflammatory processes occur in both term and preterm delivery, the premature activation of these processes or exaggerated inflammatory response triggered by infection or sterile factors leads to preterm delivery. Platelet activating factor (PAF) is a phosphoglycerylether lipid mediator of inflammation that is implicated in infections, cancers, and various chronic diseases and disorders including cardiovascular, renal, cerebrovascular, and central nervous system diseases. In gestational tissues, PAF mediates the inflammatory pathways that stimulate the effector mechanisms of labor, including myometrial contraction, cervical dilation, and fetal membrane rupture. Women with preterm labor and preterm premature rupture of membranes have increased levels of PAF in their amniotic fluid. In mice, the intrauterine or intraperitoneal administration of carbamyl PAF activates inflammation in gestational tissues, thereby eliciting preterm delivery. This review summarizes recent research on PAF as an important inflammatory mediator in preterm delivery and in other inflammatory disorders, highlighting its potential value for prediction, intervention, and prevention of these diseases.

Sex-Specific Variations in the mRNA Levels of Candidate Genes in Peripheral Blood Mononuclear Cells from Patients with Diabetes: A Multistep Study

BACKGROUND

Type 2 diabetes (T2D) is one of the most prevalent diseases that also show sexual dimorphism in many different aspects.

OBJECTIVES

This study aimed to distinguish the mRNA expression of genes in peripheral blood mononuclear cells (PBMCs) in men or women with T2D using a multistep analysis.

METHODS

A total of 95 patients with T2D were compared based on their sex in terms of clinical variables and mRNA expression in their PBMCs.

RESULTS

Men with T2D had lower LDLC, HDLC, and HbA1c values in their blood, but greater creatinine levels. In men with T2D, TLR4, CCR2, NOX2, and p67phox mRNA expression was greater, but IL6 and NF-κB mRNA expression was lesser in PBMCs. There was a link between fasting plasma glucose (FPG), triglycerides, and hs-CRP, as well as COX1 mRNA in men with T2D. In women with T2D, FPG was associated with the mRNA expression of THBS1 and p67phox, as well as triglycerides and HDLC levels. We found the exclusive effect of FPG on HDLC, HbA1c, as well as p67phox mRNA in PBMCs of women with T2D. Analysis revealed the exclusive effect of FPG on hs-CRP and PAFR mRNA in PBMCs of men with T2D. FPG was shown to be associated with body mass index, hs-CRP, triglycerides, and COX1 mRNA in men with T2D, and with serum triglycerides, THSB1, and p67phox mRNA in women with T2D, according to network analysis. HbA1c was linked with NF-κB mRNA in women with T2D.

CONCLUSIONS

Using a multistep analysis, it was shown that network analysis outperformed traditional analytic techniques in identifying sex-specific alterations in mRNA gene expression in PBMCs of T2D patients. The development of sex-specific therapeutic approaches may result from an understanding of these disparities.

Identification of potential biological processes and key genes in diabetes-related stroke through weighted gene co-expression network analysis

BACKGROUND

Type 2 diabetes mellitus (T2DM) is an established risk factor for acute ischemic stroke (AIS). Although there are reports on the correlation of diabetes and stroke, data on its pathogenesis is limited. This study aimed to explore the underlying biological mechanisms and promising intervention targets of diabetes-related stroke.

METHODS

Diabetes-related datasets (GSE38642 and GSE44035) and stroke-related datasets (GSE16561 and GSE22255) were obtained from the Gene Expression omnibus (GEO) database. The key modules for stroke and diabetes were identified by weight gene co-expression network analysis (WGCNA). Gene Ontology (GO) and Kyoto Encyclopedia of Genes Genomes (KEGG) analyses were employed in the key module. Genes in stroke- and diabetes-related key modules were intersected to obtain common genes for T2DM-related stroke. In order to discover the key genes in T2DM-related stroke, the Cytoscape and protein-protein interaction (PPI) network were constructed. The key genes were functionally annotated in the Reactome database.

RESULTS

By intersecting the diabetes- and stroke-related crucial modules, 24 common genes for T2DM-related stroke were identified. Metascape showed that neutrophil extracellular trap formation was primarily enriched. The hub gene was granulin precursor (GRN), which had the highest connectivity among the common genes. In addition, functional enrichment analysis indicated that GRN was involved in neutrophil degranulation, thus regulating neutrophil extracellular trap formation.

CONCLUSIONS

This study firstly revealed that neutrophil extracellular trap formation may represent the common biological processes of diabetes and stroke, and GRN may be potential intervention targets for T2DM-related stroke.

CCND1 Overexpression in Idiopathic Dilated Cardiomyopathy: A Promising Biomarker?

Cardiomyopathy, a disorder of electrical or heart muscle function, represents a type of cardiac muscle failure and culminates in severe heart conditions. The prevalence of dilated cardiomyopathy (DCM) is higher than that of other types (hypertrophic cardiomyopathy and restrictive cardiomyopathy) and causes many deaths. Idiopathic dilated cardiomyopathy (IDCM) is a type of DCM with an unknown underlying cause. This study aims to analyze the gene network of IDCM patients to identify disease biomarkers. Data were first extracted from the Gene Expression Omnibus (GEO) dataset and normalized based on the RMA algorithm (Bioconductor package), and differentially expressed genes were identified. The gene network was mapped on the STRING website, and the data were transferred to Cytoscape software to determine the top 100 genes. In the following, several genes, including VEGFA, IGF1, APP, STAT1, CCND1, MYH10, and MYH11, were selected for clinical studies. Peripheral blood samples were taken from 14 identified IDCM patients and 14 controls. The RT-PCR results revealed no significant differences in the expression of the genes APP, MYH10, and MYH11 between the two groups. By contrast, the STAT1, IGF1, CCND1, and VEGFA genes were overexpressed in patients more than in controls. The highest expression was found for VEGFA, followed by CCND1 (p < 0.001). Overexpression of these genes may contribute to disease progression in patients with IDCM. However, more patients and genes need to be analyzed in order to achieve more robust results.

Luseogliflozin and caloric intake restriction increase superoxide dismutase 2 expression, promote antioxidative effects, and attenuate aortic endothelial dysfunction in diet-induced obese mice

AIMS/INTRODUCTION

The mechanisms underlying the effect of sodium-glucose cotransporter 2 (SGLT2) inhibitors on aortic endothelial dysfunction in diet-induced obesity are not clearly understood. This study investigated whether SGLT2 inhibition by luseogliflozin improved free fatty acid (FFA)-induced endothelial dysfunction in high-fat diet (HFD)-induced obese mice.

MATERIALS AND METHODS

Mice were fed a control diet or high-fat diet for 8 weeks, and then each diet with or without luseogliflozin was provided for an additional 8 weeks under free or paired feeding. Afterward, the thoracic aortas were removed and utilized for the experiments.

RESULTS

Luseogliflozin treatment decreased body weight, fasting blood glucose, insulin, and total cholesterol in HFD-fed mice only under paired feeding but not under free feeding. Endothelial-dependent vasodilation under FFA exposure conditions was significantly lower in HFD-fed mice than in control diet-fed mice, and luseogliflozin treatment ameliorated FFA-induced endothelial dysfunction. Reactive oxygen species (ROS) production induced by FFA was significantly increased in HFD-induced obese mice. Luseogliflozin treatment increased the expression of superoxide dismutase 2 (SOD2), an antioxidative molecule, and reduced FFA-induced ROS production in the thoracic aorta. Superoxide dismutase reversed FFA-induced endothelial dysfunction in HFD-fed mice.

CONCLUSIONS

It was shown that caloric restriction is important for the effect of luseogliflozin on metabolic parameters and endothelial dysfunction. Furthermore, SGLT2 inhibition by luseogliflozin possibly ameliorates FFA-induced endothelial dysfunction by increasing SOD2 expression and decreasing reactive oxygen species production in the thoracic aorta.

PAF signaling plays a role in obesity-induced adipose tissue remodeling

BACKGROUND/OBJECTIVES

Platelet-activating factor receptor (PAFR) activation controls adipose tissue (AT) expansion in animal models. Our objective was twofold: (i) to check whether PAFR signaling is involved in human obesity and (ii) investigate the PAF pathway role in hematopoietic or non-hematopoietic cells to control adipocyte size.

MATERIALS/SUBJECTS AND METHODS

Clinical parameters and adipose tissue gene expression were evaluated in subjects with obesity. Bone marrow (BM) transplantation from wild-type (WT) or PAFR^-/- mice was performed to obtain chimeric PAFR-deficient mice predominantly in hematopoietic or non-hematopoietic-derived cells. A high carbohydrate diet (HC) was used to induce AT remodeling and evaluate in which cell compartment PAFR signaling modulates it. Also, 3T3-L1 cells were treated with PAF to evaluate fat accumulation and the expression of genes related to it.

RESULTS

PAFR expression in omental AT from humans with obesity was negatively correlated to different corpulence parameters and more expressed in the stromal vascular fraction than adipocytes. Total PAFR^-/- increased adiposity compared with WT independent of diet-induced obesity. Differently, WT mice receiving PAFR^-/--BM exhibited similar adiposity gain as WT chimeras. PAFR^-/- mice receiving WT-BM showed comparable augmentation in adiposity as total PAFR^-/- mice, demonstrating that PAFR signaling modulates adipose tissue expansion through non-hematopoietic cells. Indeed, the PAF treatment in 3T3-L1 adipocytes reduced fat accumulation and expression of adipogenic genes.

CONCLUSIONS

Therefore, decreased PAFR signaling may favor an AT accumulation in humans and animal models. Importantly, PAFR signaling, mainly in non-hematopoietic cells, especially in adipocytes, appears to play a significant role in regulating diet-induced AT expansion.

Rupatadine, a dual antagonist of histamine and platelet-activating factor (PAF), attenuates experimentally induced diabetic nephropathy in rats

The role of histamine and platelet activating factor (PAF) as involved mediators in the pathophysiology of diabetic complications, in particular diabetic nephropathy (DN), has become a new focus of concern. Accordingly, the present study designed to explore the effect of rupatadine (RUP), a dual antagonist of histamine (H1) and PAF, on the progression of experimentally induced DN in rats. Rats were divided into five groups: control, RUP alone, streptozotocin (STZ)-diabetic model, STZ/RUP (3 mg/kg/day), and STZ/RUP (6 mg/kg/day). Treatment has continued for 4 weeks after diabetes confirmation. At the end of the study, serum was collected for measurement of glucose, insulin, urea, creatinine, histamine, and PAF. Renal tissue homogenates were prepared for measuring oxidative stress indices, tumor necrosis factor (TNF-α), cystatin C, and p21. Moreover, immunohistochemical expression of transforming growth factor-β1 (TGF-β1) and p53 along with histological pictures was also conducted. Antagonizing H1 and PAF receptors by RUP ameliorated the experimentally induced DN as evident by decreasing all serum parameters augmented by STZ together with improvement of the histopathological picture. RUP administration also improved oxidative-antioxidative agents with reduction in the anti-inflammatory marker, TNF-α. Additionally, the immunohistochemical expression of the fibrosis marker; TGF-β1, was also decreased. STZ-induced DN showed a p21/p53-dependent induction of premature senescence and RUP administration decreased the expression of p21 and p53 levels in injured renal tissue. RUP represents a novel promising drug to prevent DN complicated diabetes probably via its inhibitory effect on H1 and PAF receptors. The renal protection was also related to the anti-inflammatory and antioxidant roles and PAF-facilitated senescence effect via p21/p53 signaling.

Association between changes in the mRNA expression of platelet-activating factor receptor in peripheral blood mononuclear cells and progression of diabetic nephropathy

Introduction

Several studies have recently pointed out the role of many inflammatory mediators in the progression of diabetes complications. We had previously demonstrated that mRNA expression of platelet-activating factor receptor (PAFR) in peripheral blood mononuclear cells (PBMCs) was associated with urinary albumin to creatinine ratio (ACR) and forearm flow-mediated dilatation in patients with type 2 diabetes. In an attempt to elucidate this association, patients were followed up for 1 year.

Materials and methods

We recruited 95 patients from the hospital outpatient clinic, among whom 86 were followed up for 1 year (normoalbuminuria: 40 patients, microalbuminuria: 25 patients, macroalbuminuria: 21 patients). We then measured their baseline and 12 month characteristics and collected blood samples to extract PBMCs and measure gene expressions.

Results

Despite higher mRNA expression of PAFR in PBMCs among patients with macroalbuminuria, the rise in its value was not associated with biomarkers of nephropathy, while baseline values were not associated with progression of nephropathy. Moreover, changes in mRNA expression of PAFR were correlated with changes in ACR in all patients (r = 0.225, p = 0.037) and estimated glomerular filtration rate in patients with macroalbuminuria (r =  - 0.438, p = 0.047) during the follow-up period.

Conclusion

Our findings indicate that even though no causal relationship exists between diabetic nephropathy and elevated expression of PAFR in PBMCs, their close association signifies the presence of another common mechanism that could induce both events. Given these findings, the PAF/PAFR interaction could clarify corresponding mechanisms involved in diabetic complications.

Expression of LRP1 and CHOP genes associated with peripheral neuropathy in type 2 diabetes mellitus: Correlations with nerve conduction studies

AIM

Diabetic peripheral neuropathy (DPN) is a frequent and debilitating complication of diabetes mellitus. The low-density lipoprotein receptor-related protein-1 (LRP-1) is a multifunctional cell surface receptor playing critical roles in lipoprotein metabolism and several cell signaling processes. C/EBP homologous protein (CHOP) is a main conduit to endoplasmic reticulum stress-induced apoptosis. We aimed to investigate LRP1 and CHOP gene expression in peripheral blood cells of type 2 diabetes mellitus (T2DM) subjects to clarify its possible relation to DPN pathogenesis.

METHOD

The study included 20 non-complicated T2DM subjects, 20 subjects with DPN and 20 healthy controls. Quantitative real time PCR was used to study gene expression.

RESULTS

There was a significant reduction in LRP1 mRNA expression and a significant increase in CHOP mRNA expression in subjects with DPN compared to non-complicated group and healthy controls. Both LRP1 and CHOP expression levels were inversely correlated, and both showed significant correlation with HbA1c, hyperlipidemia, hs-CRP, and different electrophysiological parameters. Receiver operating characteristics (ROC) analysis suggested that both LRP1 and CHOP mRNA expression and hs-CRP levels had great potential advantages to predict the progression of DPN.

CONCLUSION

LRP1 and CHOP might be involved in DPN pathogenesis and progression, thus providing opportunities for early detection and treatment.