Translational regulation of human methionine synthase by upstream open reading frames

Methionine synthase is a key enzyme poised at the intersection of folate and sulfur metabolism and functions to reclaim homocysteine to the methionine cycle. The 5' leader sequence in human MS is 394 nucleotides long and harbors two open reading frames (uORFs). In this study, regulation of the main open reading frame by the uORFs has been elucidated. Both uORFs downregulate translation as demonstrated by mutation of the upstream AUG codons (uAUG) either singly or simultaneously. The uAUGs are capable of recruiting the 40S ribosomal complex as revealed by their ability to drive reporter expression in constructs in which the luciferase is fused to the uORFs. uORF2, which is predicted to encode a 30 amino acid long polypeptide, has a clustering of rare codons encoding arginine and proline. Mutation of a tandemly repeated rare codon for arginine at positions 3 and 4 in uORF2 to either common codons for the same amino acid or common codons for alanine results in complete alleviation of translation inhibition. This suggests a mechanism for ribosome stalling and demonstrates that the cis-effects on translation by uORF2 is dependent on the nucleotide sequence but is apparently independent of the sequence of the encoded peptide. This study reveals complex regulation of the essential housekeeping gene, methionine synthase, by the uORFs in its leader sequence.     

Impact of hemostatic gene single point mutations in patients with non-diabetic coronary artery disease

Single point mutations in the genes coding for hemostatic factors were shown to be major inherited predisposing factors for venous thromboembolism. However, their contribution in the development of non-diabetic coronary artery disease [nDCAD] remains controversial. Angiographically demonstrated nDCAD patients (n = 86) and healthy controls (n = 90) were included in the study. Genotype analysis of hemostatic gene polymorphisms were assessed by using CVD strip assay, based on allele specific oligonucleotide probes. The carrier frequency of factor V (FV) H1299R, prothrombin G20210A, glycoprotein (Gp) IIIa L33P, plasminogen activator inhibitor-I (PAI-1) 4G/5G, 4G/4G, 5G/5G, methylenetetrahydrofolate reductase (MTHFR) A1298C and β-fibrinogen −455 G > A were similar between patients and controls. In contrast, frequency of FV Leiden was significantly higher among patients (12.5%) than controls (5%, OR: 7.94; 95%CI: 1.9–49.6) and FXIII V34L was significantly lower among patients (23.7%) than controls (40%, OR: 0.24; 95%CI: 0.1–0.89). In addition, the frequency of the MTHFR C677T polymorphism was 32.5% among patients compared with 42.5% in controls, of which the T/T genotype was significantly lower among patients (5%) than controls (17.5%, OR: 0.06; 95%CI: 0.01–0.58). No difference was observed in prevalence of prothrombin G20210A, FV H1299R, Gp IIIa L33P, PAI-1 4G5G, MTHFR A1298C, β fibrinogen 455 G > A mutations between patients and controls. However, lower frequency of FXIII Val34Leu and MTHFR C677T polymorphisms may decrease, while FV Leiden polymorphism may increase development of nDCAD.     

Screening for celiac disease in poorly controlled type 2 diabetes mellitus: worth it or not?

Background

Recent studies have demonstrated that immune factors might have a role in the pathophysiology of insulin resistance and type 2 diabetes mellitus (T2DM). Inappropriate glycemic control in patients with T2DM is an important risk factor for the occurrence of diabetes complications. The prevalence of celiac disease (CD) is high in type 1 diabetes mellitus however, there are scarce data about its prevalence in T2DM. Our aim was to investigate the prevalence of celiac disease among insulin-using type 2 diabetes patients with inappropriate glycemic control.

Methods

IgA tissue transglutaminase antibodies (tTGA IgA) test was performed as a screening test. A total of 135 patients with T2DM whose control of glycemia is inappropriate (HbAlc value >7%) in spite of using insulin treatment for at least 3-months (only insulin or insulin with oral antidiabetic drugs) and 115 healthy controls were enrolled in the study. Upper gastrointestinal endoscopy with duodenal biopsy was performed to all patients with raised tTGA IgA or selective lgA deficiency.

Results

Gender, age, body mass index (BMI) and tTGA IgA, kreatinin, calcium, LDL-cholesterol (LDL-C), total cholesterol, 25-OH vitamin D₃ levels were similar between groups. Systolic and diastolic blood pressure, waist circumference, fasting plasma glucose, postprandial plasma glucose, urea, sodium, HbA1c, LDL-C, triglyceride, vitamin B12 levels were significantly higher in DM group (p < 0.0001). BMI, high-sensitive CRP, microalbuminuria, and AST, ALT, potassium, phosphorus levels were significantly higher in the T2DM group (p < 0.05). HDL-cholesterol and parathormone levels were significantly lower in the T2DM group (p < 0.05). Two of the 135 patients with T2DM were diagnosed with CD (1.45%).

Conclusions

The prevalence of celiac disease among patients with type 2 diabetes, with poor glycemic control despite insulin therapy, is slightly higher than the actual CD prevalence in general population. Type 2 diabetic patients with inappropriate control of glycemia in spite of insulin treatment might be additionally tested for Celiac disease especially if they have low C-peptide levels.

     

Dye-incorporated poly(EGDMA-HEMA) microspheres as specific sorbents for aluminum removal

Aluminum [Al(III)] adsorption onto dye-incorporated poly(ethylene glycol dimethacrylate-hydroxyethyl methacrylate) [poly(EGDMA-HEMA)] microspheres was investigated. Poly(EGDMA-HEMA) microspheres, in the size range of 150–200 μm, were produced by a modified suspension polymerization of EGDMA and HEMA. The reactive dyes (i.e., Congo Red, Cibacron Blue F3GA and Alkali Blue 6B) were covalently incorporated to the microspheres. The maximum dye load was 14.5 μmol Congo Red/g, 16.5 μmol Cibacron Blue F3GA/g and 23.7 μmol Alkali Blue 6B/g polymer. The maximum Al(III) adsorption on the dye microspheres from aqueous solutions containing different amounts of Al(III) ions were 27.9 mg/g, 17.3 mg/g and 12.2 mg/g polymer for the Congo Red, Cibacron Blue F3GA and Alkali Blue 6B, respectively. The maximum Al(III) adsorption was observed at pH 7.0 in all cases. Non-specific Al(III) adsorption was about 0.84 mg/g polymer under the same conditions. High desorption ratios (95%) were achieved in all cases by using 0.1 M HNO₃. It was possible to reuse these dye-incorporated poly(EGDMA-HEMA) microspheres without significant losses in the Al(III) adsorption capacities.     

The effect of lipoic acid on wound healing in a full thickness uterine injury model in rats

Aim of this study was to investigate the effects of lipoic acid on uterine wound healing by immunohistochemical and biochemical assay in a rat uterine horn model with full thickness injury. Thirty-two female Wistar albino rats were randomised into five groups: Control group, with no intervention; uterine scar group 15days (US15d), uterine scar group 15 days + alpha lipoic acid (ALA) (US15d + ALA), uterine scar group 30 days (US30d) and uterine scar group 30 days + ALA (US30 days + ALA). After uterine incision 100 mg/kg of ALA was administered by oral gavage for either 15 or 30 days. Vascular endothelial growth factor (VEGF) and alpha smooth muscle actin (α-SMA) distribution were evaluated by immunohistochemical methods in tissue and ELISA methods in tissue homogenate. The percentage of α-SMA positive area in US15d + ALA and US30d + ALA groups was significantly higher than US15 and US30d groups. The percentage of VEGF positive area in US15d + ALA group was significantly higher than US15d group and US30d + ALA group was significantly higher than US30d group. Biochemically, α-SMA was significantly higher in the US15d + ALA group when compared to US15d group and higher in US30d + ALA group when compared to US30d group. VEGF was significantly higher in US15d + ALA and US30d + ALA groups when compared to US15 and US30d groups. In conclusion, ALA was found to be effective in enhancing wound healing in uterine full thickness injury.     

<Emphasis Type="Italic">Jurinea turcica</Emphasis> (Asteraceae), a new species from North-West Anatolia,Turkey

Jurinea turcica B.Doǧan & A.Duran sp. nova (Asteraceae) is described and illustrated from North-West Anatolia, Turkey. It is closely related to J. macrocalathia and also an endemic. Diagnostic morphological characters of J. turcica from closely similar taxa are discussed. The pollen characteristics and achene surface morphology of J. turcica and J. macrocalathia are examined by SEM. It is diploid with the chromosome number of 2n = 34.