The novel allele (3R) of the VNTR polymorphism in the XRCC5 promoter region dramatically decreases the gene expression

Polymorphism of variable number of tandem repeats (VNTR) in the promoter region of X-ray repair cross-complementing 5 (MIM: 194364, XRCC5; rs6147172) was reported. The aim of the present study is to evaluate the influence of this polymorphism on XRCC5 mRNA levels. Genotypes of XRCC5 VNTR were determined by high resolution of melting analysis (HRMA). The quantitative XRCC5 mRNA expression (compared to ß-actin expression) among 0R/1R, 1R/2R, and 1R/3R genotypes was investigated. There was a negative correlation between the overall number of tandem repeats and XRCC5 expression (r = ?0.965, df = 7, P < 0.001). The mRNA level of XRCC5 decreased as function of number of tandem repeats. The 3R allele of the VNTR polymorphism in the XRCC5 promoter region dramatically decreases the gene expression.     

Comparison of expression optimization of new derivative of staphylokinase (SAK-2RGD-TTI) with the rSAK

Staphylokinase (SAK) is a promising thrombolytic agent for the treatment of patients suffering from blood-clotting disorders. To increase the potency of SAK and to minimize vessel reocclusion, a new construct bearing SAK motif fused to tsetse thrombin inhibitor (TTI) via a 20-amino acid linker with 2 RGD (2 × arginine-glycine-aspartic acid inhibiting platelet aggregation via attachment to integrin receptors of platelet) was codon optimized and expressed comparatively in Pichia pastoris GS115 as a Mut⁺ strain and KM71H as a Mut^s strain. Fusion protein was optimized in terms of best expression condition and fibrinolytic activity and compared with the rSAK. Expression level of the designed construct reached up to 175 mg/L of the culture medium after 72-hr stimulation with 2.5% methanol and remained steady for 3–4 days. The highest expression was obtained at the range of 2–3% methanol. The SAK-2RGD-TT (relative activity >82%) was more active at 25–37 °C than rSAK (relative activity of 93%). Further, it showed relative activity >80% at pH ranges of 7–9. Western blot analysis showed two bands of nearly 27 and 24 kDa at ratio of 5 to 3, respectively. The specific fibrinolytic activity of the SAK-2RGD-TTI was measured as 8,269 U/mg, and 19,616 U/mg for the nonpurified and purified proteins, respectively. Deglycosylation by using tunicamycin in culture medium resulted in higher fibrinolytic activity of SAK-2RGD-TTI (2.2 fold). Consequently, compared to the rSAK, at the same equimolar proportion, addition of RGD and TTI fragments could increase fibrinolytic activity. Also, P. pastoris can be considered as an efficient host for overexpression of the soluble SAK-2RGD-TTI with high activity without requiring a complicated purification procedure.     

High-density lipoprotein lipid peroxidation as a molecular signature of the risk for developing cardiovascular disease: Results from MASHAD cohort

High-density lipoprotein (HDL) function rather than level may better predict cardiovascular disease (CVD). However, the contribution of the impaired antioxidant function of HDL that is associated with increased HDL lipid peroxidation (HDLox) to the development of clinical CVD remains unclear. We have investigated the association between serum HDLox with incident CVD outcomes in Mashhad cohort. Three-hundred and thirty individuals who had a median follow-up period of 7 years were recruited as part of the cohort. The primary end point was cardiovascular event, including myocardial infarction, stable angina, unstable angina, or coronary revascularization. In both univariate/multivariate analyses adjusted for traditional CVD risk factors, HDLox was an independent risk factor for CVD (odds ratio, 1.62; 95% confidence interval, 1.41–1.86; p < 0.001). For every increase in HDLox by 0.1 unit, there was an increase in CVD risk by 1.62-fold. In an adjusted analysis, there was a >2.5-fold increase in cardiovascular risk in individuals with HDLox higher than cutoff point of 1.06 compared to those with lower scores, suggesting HDLox > 1.06 is related to the impaired HDL oxidant function and in turn exposed to elevated risk of CVD outcomes (hazard ratio, 2.72; 95% CI, 1.88–3.94). Higher HDLox is a surrogate measure of reduced HDL antioxidant function that positively associated with cardiovascular events in a population-based cohort.     

Modulation of hematology changes by polymorphism of glutathione S-transferase M1 and T1

Workers in the petroleum distribution trades experience relatively low-level exposures to gasoline vapors whose consequences have not been fully elucidated. The purpose of this study was to investigate changes in the hematological parameters among filling station workers who were occupationally exposed to gasoline. The target group for the study consisted of 41 workers from eight filling stations of Shiraz (south of Iran). The control group consisted of 27 healthy subjects matched for age and sex from general population. The complete blood count analysis was done in one laboratory. Using PCR-based method, the genotypes of glutathione S-transferase T1 (GSTT1) and M1 (GSTM1) were determined. Workers were divided into three exposure groups according to employment history: duration less than 1 year, 1-5 years, and more than 5 years. Comparison was performed using Kruskal-Wallis test. In the individuals with the presence of both GSTT1 and GSTM1 functional alleles, comparison between four exposure groups revealed no significant difference for studied hematological variables. There were statistically significant differences between study groups, with only one functional allele, either GSTT1 or GSTM1, for relative number of lymphocytes (chi(2)=9.147, df=3, P=0.027) and neutrophils (chi(2)=9.951, df=3, and P=0.019), and absolute number of lymphocytes (chi(2)=9.135, df=3, and P=0.028), and RBC (chi(2)=10.586, df=3, and P=0.014). These findings could indicate the possible protective effect of concurrent presence of GSTM1 and GSTT1 enzymes on the hematopoietic system of filling station workers.     

The effect of carbon source supplementation on the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by Cupriavidus necator

The objective of the present study was to investigate the ability of Cupriavidus necator to produce poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) on various carbon sources in batch cultivation. These results show that C. necator produces poly-3-hydroxybutyrate from single carbon sources. The highest poly-3-hydroxybutyrate (P3HB) content was achieved at growth on fructose in the exponential growth phase. The maximum yield of the P3HV content was obtained when fructose was mixed with acetate. The highest content P3HB-co-3HV was also achieved by C. necator when we supplied C-excess and N- and P-normal conditions. These results indicate that C. necator accumulates high polyhydroxyalkanoates (PHA) content by depleting these elements in the culture medium. Nitrogen and phosphorus limitation has no significant effect on the PHA production, whereas C-excess leads to an increase in PHA formation of up to 92% PHAs of cell dry weight after growth on 5 g/L acetate and 40 g/L fructose.     

Impaired striatal Akt signaling disrupts dopamine homeostasis and increases feeding

Background

The prevalence of obesity has increased dramatically worldwide. The obesity epidemic begs for novel concepts and therapeutic targets that cohesively address “food-abuse” disorders. We demonstrate a molecular link between impairment of a central kinase (Akt) involved in insulin signaling induced by exposure to a high-fat (HF) diet and dysregulation of higher order circuitry involved in feeding. Dopamine (DA) rich brain structures, such as striatum, provide motivation stimuli for feeding. In these central circuitries, DA dysfunction is posited to contribute to obesity pathogenesis. We identified a mechanistic link between metabolic dysregulation and the maladaptive behaviors that potentiate weight gain. Insulin, a hormone in the periphery, also acts centrally to regulate both homeostatic and reward-based HF feeding. It regulates DA homeostasis, in part, by controlling a key element in DA clearance, the DA transporter (DAT). Upon HF feeding, nigro-striatal neurons rapidly develop insulin signaling deficiencies, causing increased HF calorie intake.

Methodology/Principal Findings

We show that consumption of fat-rich food impairs striatal activation of the insulin-activated signaling kinase, Akt. HF-induced Akt impairment, in turn, reduces DAT cell surface expression and function, thereby decreasing DA homeostasis and amphetamine (AMPH)-induced DA efflux. In addition, HF-mediated dysregulation of Akt signaling impairs DA-related behaviors such as (AMPH)-induced locomotion and increased caloric intake. We restored nigro-striatal Akt phosphorylation using recombinant viral vector expression technology. We observed a rescue of DAT expression in HF fed rats, which was associated with a return of locomotor responses to AMPH and normalization of HF diet-induced hyperphagia.

Conclusions/Significance

Acquired disruption of brain insulin action may confer risk for and/or underlie “food-abuse” disorders and the recalcitrance of obesity. This molecular model, thus, explains how even short-term exposure to “the fast food lifestyle” creates a cycle of disordered eating that cements pathological changes in DA signaling leading to weight gain and obesity.     

Alterations in blood pressure due to chronic exposure to natural sour gas leakage containing sulfur compounds

In order to show the alteration of blood pressure in subjects chronically exposed to natural gas containing sulfur compounds, the present study was done. The blood pressure of 94 (43 males, 51 females) of healthy individuals living in the polluted area of Masjid-i-Sulaiman (Khozestan province, southwest of Iran) was measured. The non-parametric Sign test was applied in order to detect differences between the study subjects and the normal mean values according to the sex and age of subjects. Statistical analysis showed that the systolic blood pressure significantly decreased (Z=-2.74; P=0.0031) while the diastolic blood pressure (Z=+2.11; P=0.0174) and heart rate (Z=+3.62; P<0.001) significantly increased in individuals living in the contaminated areas compared with those of normal mean values. The systolic and diastolic blood pressure decreased and increased, respectively, in individuals chronically exposed to natural sour gas containing sulfur compounds.     

Clinical response to chemotherapy in locally advanced breast cancer was not associated with several polymorphisms in detoxification enzymes and DNA repair genes

The main aim of the present study was to investigate the association between several genetic polymorphisms (in glutathione S-transferase members and DNA repair genes) and clinical response to chemotherapy in locally advanced breast cancer. A sequential series of 101 patients were prospectively included in this study. Clinical assessment of treatment was accomplished by comparing initial tumor size with preoperative tumor size using revised RECIST guideline (version 1.1). Clinical response was regarded as a response or no response. There was no difference between non-responders and responders for the prevalence of genotypes of the study polymorphisms.