Effects of Glucose Ingestion on Serum Fractalkine Levels in Healthy Subjects and Newly Diagnosed Type 2 Diabetic Patients

FKN/NR Signaling Pathway Regulates Hippocampal Inflammatory Responses: the Survival of Hippocampal Neurons in Diabetic Rats with Chronic Unpredictable Mild Stress

Aim

To investigate the mechanism via which FKN/CX3CR1 signaling abnormalities mediate N-methyl-D-aspartic acid receptor (NMDA) overexcitation-induced hippocampal neuronal injury in diabetic rats complicated with depression (DD).

Methods

Sixty rats were randomly divided into 5 groups. The depression-like behaviors of the rats were evaluated by open field test and Morris water maze. The pathological changes of hippocampus in DD rats were observed by HE staining. The blood levels of inflammatory factors (IL-1β, TNF-α, and IL-6) and neurotransmitters (D-serine and glutamic acid) were determined by enzyme-linked immunosorbent assay (ELISA). The expressions of BDNF, A1 receptor (A1R), A2 receptor (A2R), A3 receptor (A3R), calmodulin dependent kinase II (CaMKII), CX3CR1, CX3CL1 (FKN), NR2A, and NR2B proteins were detected by immunohistochemistry and Western-blotting.

Results

Compared with the normal control group, blood glucose level increased significantly and body weight decreased in T2DM group and T2DMC group. In addition, the number of spontaneous activities significantly decreased and the capability of learning and memory was attenuated in T2DMC group and Chronic Stress group. The blood levels of IL-1β, TNF-α, IL-6, glutamate (Glu), and D-serine significantly increased in each model group. After intervention with CX3CR1 antibody, the expressions of BDNF, CaMK II, A1R, and A3R increased and those of A2R, CX3CR1, FKN, NR2A, and NR2B decreased.

Conclusion

In the diabetic state, the binding of FKN to CX3CR1 increases, which regulates a variety of adenosine receptors. When it exerts its effect on neurons, the overactivation of NR results in neuronal injury and causes depression.

Chemokines in Prediabetes and Type 2 Diabetes: A Meta-Analysis

Background

A growing number of studies found inconsistent results on the role of chemokines in the progression of type 2 diabetes (T2DM) and prediabetes (PDM). The purpose of this meta-analysis was to summarize the results of previous studies on the association between the chemokines system and T2DM/PDM.

Methods

We searched in the databases, PubMed, Web of Science, Embase and Cochrane Library, for eligible studies published not later than March 1, 2020. Data extraction was performed independently by 2 reviewers, on a standardized, prepiloted form. Group differences in chemokines concentrations were summarized using the standardized mean difference (SMD) with a 95% confidence interval (CI), calculated by performing a meta-analysis using the random-effects model.

Results

We identified 98 relevant studies that investigated the association between 32 different chemokines and T2DM/PDM. Altogether, these studies involved 14,708 patients and 14,574 controls. Results showed that the concentrations of CCL1, CCL2, CCL4, CCL5, CCL11, CXCL8, CXCL10 and CX3CL1 in the T2DM patients were significantly higher than that in the controls, while no difference in these concentrations was found between the PDM patients and controls.

Conclusion

Progression of T2DM may be associated with elevated concentrations of chemokines.

Meta-Analysis Registration

PROSPERO, identifier CRD42019148305.

Circulating myokine levels in different stages of glucose intolerance

Type 2 diabetes is the fastest growing metabolic disease in the world. Recently, muscle is considered an endocrine organ which secretes various peptides that play an important role in insulin resistance and metabolic syndrome. We assessed 4 different myokines, irisin, interleukin-13 (IL-13), follistatin-related protein-1 (FSTL-1), and fractalkine, in normal, prediabetes, and diabetes patients.A total of 126 participants who visited Gangnam Severance Hospital were enrolled and divided into normal, prediabetes, and diabetes groups based on oral glucose tolerance test and hemoglobin a1c. A cross-sectional study was conducted to measure and compare serum levels of irisin, IL-13, FSTL-1, and fractalkine among the groups.Irisin level showed a tendency to increase in prediabetes group compared to normal group (P < .1) but showed a significant decrease when comparing diabetes from prediabetes group (P < .001). IL-13 decreased in diabetes group compared to prediabetes and normal group (P < .001, P < .05, respectively). FSTL-1 of diabetes group was lower than that of prediabetes group (P < .05), and fractalkine was higher in diabetes group compared to that of prediabetes and normal group (P < .01, P < .01, respectively).Irisin, IL-13, and FSTL-1 levels were reduced in diabetes group compared to normal or prediabetes group while fractalkine showed a progressive increase from normal to diabetes group. Further studies are warranted to study the roles of various myokine in diabetes through a larger prospective study.

Saliva diagnostic utility in patients with type 2 diabetes: Future standard method

Background

The purpose of the present study was to assess saliva reliability in diagnosis and monitoring type 2 diabetes instead of blood.

Methods

Blood and unstimulated whole saliva were collected from 300 type 2 diabetic subjects and 300 healthy controls in fasting. Then, the salivary flow rate was calculated. All parameters including glucose, urea, amylase, total protein, albumin, C-reactive protein (CRP), immunoglobulin A (IgA), potassium, calcium and chloride were assessed in the supernatant, using an autoanalyzer. Oral exam was conducted by a single examiner on full mouth excluding third molars. Statistical analysis was performed by the SPSS 20.0 version.

Results

Saliva screening showed that glucose, urea, amylase, total protein, potassium, calcium and chloride were significantly higher in patients compared to controls (p < 0.05). Whereas, the IgA level and salivary flow rate were significantly reduced in patients (p < 0.05). No significant difference was found in albumin and CRP levels (p > 0.05). There was a significant positive correlation between salivary and plasma glucose levels (r = 0.887, and r = 0.900, p < 0.001), as well as, salivary and blood urea (r = 0.586, and r = 0.688, p < 0.001) in patients and controls, respectively.

Conclusions

From this study, saliva could be suggested as a useful diagnostic tool for type 2 diabetes.

Effects of Timolol Treatment on Pancreatic Antioxidant Enzymes in Streptozotocin-induced Diabetic Rats: An Experimental and Computational Study

BACKGROUND

The study aimed to investigate whether timolol-treatment has a beneficial effect on pentose phosphate pathway enzyme activities such as glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGDH) enzyme activities and cAMP level in streptozotocin-induced diabetic rats in pancreatic tissues.

METHODS

Diabetes was induced by streptozotocin (STZ) in 3-month old male Wistar rats. The diabetic rats were treated with timolol (5 mg/kg body weight, for 12 weeks) while the control group received saline. Enzyme activities were determined in pancreas tissue. To support our results, we performed in silico calculations, using Protein Data Bank structures.

RESULTS

Timolol treatment of STZ-induced diabetic rats had no noteworthy effect on high blood-glucose levels. However, this treatment induced activities of G6PD and 6PGDH in diabetic rats. Timolol treatment significantly increased cAMP level in diabetic pancreatic tissue. We found that timolol cannot bind strongly to either G6PD or 6PGD, but there is a relatively higher binding affinity to adenylyl cyclase, responsible for cAMP production, serving as a regulatory signal via specific cAMP-binding proteins.

CONCLUSIONS

Our data point out that timolol treatment has beneficial effects on the antioxidant defence mechanism enzymes in the pancreas of STZ-induced diabetic rats.

Urinary nephrin is earlier, more sensitive and specific marker of diabetic nephropathy than microalbuminuria

Background

Diabetic nephropathy (DN) is a leading cause of end-stage renal disease. Progressive damage and decline in the number of podocytes often occur in the early stages of DN. Thus, nephrin as a podocyte-specific protein may be regarded as a potential biomarker of early detection of DN. The aim of this study is to determine whether urinary nephrin is an earlier marker in DN than microalbuminuria and to test the significance of urinary nephrin as a marker for early detection of DN.

Methods

Our cross-sectional study included 90 patients with type 2 diabetes mellitus (T2DM), 30 patients with diagnosed DN and 60 patients without diagnosed DN. As a control group, we used 30 healthy subjects. All patients with T2DM were classified into three subgroups according to urinary microalbumin/creatinine ratio (UMCR): normoalbuminuric, microalbuminuric and macroalbuminuric patients. Nephrin in urine was measured by immunoenzyme assay, microalbumin with turbidimetric and creatinine with the photometric method. In blood sera, we measured a few standard biochemical parameters.

Results

Nephrinuria was found to be present in 100% of patients with T2DM and macroalbuminuria, in 88% with microalbuminuria, as well as 82% of patients with T2DM and normoalbuminuria. A concentration of urinary nephrin was significantly increased in all groups of subjects with T2DM compared to the control group (p<0.05). Nephrinuria correlated statistically negative with eGFR (r=-0.54). ROC analysis showed that nephrin has a total predicted probability of 96% in patients with DN.

Conclusions

Urinary nephrin is earlier, more specific and sensitive marker than microalbumin in early detection of DN.

Thiol/Disulphide Homeostasis, Ischemia Modified Albumin, and Ferroxidase as Oxidative Stress Markers in Women with Obesity with Insulin Resistance

Background

The purpose of the study was to determine oxidative stress-related plasma thiol/disulphide, ischemia-modified albumin (IMA) levels and ferroxidase activity among women with obesity in insulin-resistant and non-insulin-resistant groups in comparison with an overweight group.

Methods

We compared plasma thiol/disulphide, IMA levels, and ferroxidase activity between the study groups. We analyzed plasma thiol/disulphide homeostasis with a newly developed automated measurement method; IMA with Albumin Cobalt Binding Test and ferroxidase (ceruloplasmin) levels with an automated, colourimetric method.

Results

There were no significant differences between insulin-resistant and non-insulin-resistant women with obesity in terms of plasma native thiol, total thiol, disulphide, disulphide/native thiol ratio, disulphide/total thiol or native thiol/total thiol values. Ferroxidase activity was higher in insulin-resistant than in non-insulin-resistant women with obesity and higher in the total women with obesity group than in the overweight subjects (p<0.001, and p=0.014, respectively). IMA was lower in the insulin-resistant group than in the non-insulin-resistant group and overweight groups (p=0.011, and p=0.042, respectively).

Conclusions

The significantly greater increase in ferroxidase activity in insulin-resistant subjects with obesity may reflect its role as a positive acute phase protein. These findings may be related to the pathogenesis of the disease. Changes in oxidative status occur in women with obesity, and partially in overweight subjects. The ferroxidase activity of ceruloplasmin plays a crucial role in iron homeostasis and lowers oxidative stress by reducing the detrimental effects of iron.

Association of FTO Gene Variant (rs8050136) with Type 2 Diabetes and Markers of Obesity, Glycaemic Control and Inflammation

Background

FTO, a gene recently discovered in genomewide associated studies for type 2 diabetes mellitus (T2D), play an important role in the management of energy homeostasis, nucleic acid demethylation and regulation of body fat mass by lipolysis. The aim of this study was to analyze the association of FTO rs8050136 A>C genetic variant with clinical and biochemical parameters of T2D in the population of West Balkan region (Bosnians and Herzegovinians and Kosovars).

Methods

The study included 638 patients with T2D and prediabetes and 360 healthy controls of both genders, aged from 40 to 65 years. Patients were recruited at the Clinical Centre University of Sarajevo, University Hospital of Clinical Centre in Banja Luka, General Hospital in Tešanj and Health Centre in Prizren. Genotyping of analyzed FTO polymorphism rs8050136 A>C was performed by qPCR allelic discrimination.

Results

Genotype frequencies of the analyzed polymorphism were comparable between patients with T2D, prediabetic patients, and healthy population. Logistic regression analyses didn’t show significant association of FTO rs8050136 A allele with increased risk of T2D. However, risk A allele was significantly associated with higher levels of HbA1c, insulin, HOMA-IR index, diastolic blood pressure, and inflammatory markers (fibrinogen and leukocytes) as well as showed tendency of association with increased values of obesity markers (BMI, waist and hip circumference).

Conclusions

Results of our study showed a significant association of FTO genetic variant rs8050136 A>C with the major markers of insulin resistance, obesity and inflammation, opening new avenues for solving many unclear questions in the pathogenesis of T2D.

The Inflammatory and Hemostatic Cardiovascular Risk Markers During Acute Hyperglycemic Crisis in Type 1 and Type 2 Diabetes

Background

We analyzed cardiovascular inflammatory (C-reactive protein (CRP), interleukin 6 (IL-6)), haemostatic (homocysteine) risk markers in lean and obese patients at admission and acute hyperglicemic crisis (AHC) resolving, involving diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS).

Methods

In that context, we included group A: N = 20 obese, B: N=20 lean patients with DKA; C: N = l0 obese, D: N=10 lean patients with HHS; E: N = 15 obese, F: N=15 lean controls. CRP IL-6, homocysteine were determined by ELISA.

Results

Our results showed that CRP IL-6, and homocysteine levels decreased in all groups: (A: p<0.001; B: p<0.001, C: p<0.05; D: p<0.001 mg/L), (A: p<0.001 B: p<0.001, C: p<0.001, D: p<0.01 pg/mL), (A: p<0.001, B: p <0.001; C: p<0.05, D: p=0.001 μmol/L), respectively, at resolving AHC. However, CRP persisted higher (p<0.001, p<0.01), IL-6 lower (p<0.05, p<0.001), while homocysteine levels turned out to be similar to controls.

Conclusions

AHC is associated with increased inflammatory and hemostatic cardiovascular risk markers. Also, insulin therapy in AHC has had more pronounced favorable effect on IL-6 and homocystein than on CRP

Profiles of Circulating MiRNAs Following Metformin Treatment in Patients with Type 2 Diabetes

BACKGROUND

Metformin, a widely used biguanide class of anti-diabetic drug, has potential to increase insulin sensitivity and reduce blood glucose to treat type 2 diabetes (T2D). It has been reported that metformin has an activity on regulation of miRNAs by targeting several downstream genes in metabolic pathways. However, molecular mechanism underlying the process is still not fully known. In this study, it was aimed to identify differential expression profiles of plasma derived miRNAs following 3 months metformin treatment in patients with T2D.

METHODS

The plasma samples of 47 patients with T2D (received no anti-diabetic treatments) and plasma samples of same 47 patients received 3 months metformin treatment was recruited to the study. Total RNAs were isolated from plasma and reverse transcribed into cDNA. Profiles of differential expressions of miRNAs in plasma were assessed by using of micro-fluidic based multiplex quantitative real time -PCR (BioMarkTM 96.96 Dynamic Array).

RESULTS

Our results showed that expression profiles of 13 candidate miRNAs; hsa-let-7e-5p, hsa-let-7f-5p, hsa-miR- 21-5p, hsa-miR-24-3p, hsa-miR-26b-5p, hsa-miR-126-5p, hsa-miR-129-5p, hsa-miR-130b-3p, hsa-miR-146a-5p, hsamiR- 148a-3p, hsa-miR-152-3p, hsa-miR-194-5p, hsa-miR- 99a-5p were found significantly downregulated following metformin treatments in patients with T2D (p<0.05).

CONCLUSIONS

In conclusion, our finding could provide development of better and more effective miRNAs based therapeutic strategies against T2D.