Potential risk modifications of GSTT1, GSTM1 and GSTP1 (glutathione-S-transferases) variants and their association to CAD in patients with type-2 diabetes

Background

Type-2 diabetes mellitus (T2DM) is a major risk factor for coronary artery disease (CAD) resulting in high morbidity and mortality. Glutathione S-transferases (GSTM1, GSTT1 and GSTP1) are known for their broad range of detoxification and in the metabolism of xenobiotics. Recent studies revealed the relationship of GSTs variants with T2DM and CAD. In this case-control study we ascertained the association of GSTs variants in association with the development of CAD in patients with T2DM.

Methods

From the Southern part of India, we enrolled 222 T2DM patients, 290 T2DM patients with CAD and 270 healthy controls matched for age, sex and origin. Serum lipid profiles were measured and DNA was extracted from the blood samples. Multiplex PCR for GSTM1/T1 (null polymorphism) and PCR-RFLP for GSTP1 (105 A > G), were performed for genotyping of study participants. Gene frequency and lipid profiles were statistically analyzed for disease association.

Results

Regression analysis showed that, GSTM1-null genotype is associated with a 2-fold increase (OR = 2.925; 95% CI = 2.078–4.119; P < 0.0001) and GSTT1-null genotype is associated with a 3-fold increase (OR = 3.114; 95% CI = 2.176–4.456; P < 0.0001) to T2DM development. Ile/Val and Val/Val genotypes of GSTP1 also showed a significant risk for T2DM (OR = 1.423, CI = 1.041–1.946; P = 0.027 and OR = 1.829, CI = 1.064–3.142; P = 0.029). Increased odds ratio showed that GSTT1-null genotype had a moderately higher occurrence in T2DM–CAD patients (OR = 1.918, 95% CI = 1.144–3.214; P = 0.014) than T2DM patients without CAD. The level of HDL has significantly decreased in GSTT1-present than in GSTT1-null genotype (43.50 ± 4.10 vs. 45.20 ± 3.90; P = 0.004) when compared with control and T2DM patients. However, LDL level showed a significant increase in GSTT1-null than GSTT1-present genotype (108.70 ± 16.90 vs. 102.20 ± 12.60; P = 0.005). Although the GSTM1-null polymorphism showed no correlation with lipid profiles among T2DM and T2DM with CAD patients, GSTT1-null polymorphism attained a statistical significance for the level of LDL (127 ± 28.20 vs. 134 ± 29.10; P = 0.039) and triglycerides in T2DM with CAD patients (182.10 ± 21.10 vs. 191.20 ± 24.10; P = 0.018).

Conclusion

Our work concludes that GSTM1, GSTT1 and GSTP1 variants might contribute to the development of T2DM and GSTT1 variant alone is involved in the development of T2DM associated CAD complications in the South Indian population.     

A Simple Intervention to Prevent Cutaneous Larva Migrans among Devotees of the Nallur Temple in Jaffna,Sri Lanka

Background

A cross sectional study conducted during the annual festival at Nallur temple in Jaffna, Sri Lanka, in 2010, showed that the prevalence of cutaneous larva migrants (CLM) among the devotees who performed the side roll ritual was 58.2% (95%CI: 51.2%–65.0%).

Objective

To test the hypothesis that the deworming stray dogs around the temple premises effectively reduces the prevalence of CLM among devotees.

Methodology/Principal Findings

All stray dogs (8) in the vicinity of the temple were treated, with mebendazole (100 mg) crushed and filled into sausages, 10 days before the commencement of festival in 2011. The same procedure was repeated a week later to ensure complete coverage. A cross-sectional study was conducted among 200 systematically selected devotees in August 2011 using an interviewer-administered questionnaire and the clinical examination of the skin. Baermann''s technique was used for the recovery of nematode larvae from 40 soil samples collected from the temple premises. Ten samples of dog faeces collected from the same premises were also examined for nematode eggs. Prevalence of CLM among devotees in 2010 (Pre intervention) and 2011(Post intervention) were compared to test the hypothesis. Prevalence of CLM declined from 58% to 8% (Chi-square = 112.90, p<0.001) following the intervention. None of the subjects practiced new precautionary measures compared to the previous year. Soil and fecal samples were negative for parasites.

Conclusions/Significance

Regular dog deworming is an important and effective method for the prevention of CLM among the devotees doing side roll ritual and represents a pragmatic intervention that municipal authorities could perform on annual basis.     

Macaque Monkeys Perceive the Flash Lag Illusion

Transmission of neural signals in the brain takes time due to the slow biological mechanisms that mediate it. During such delays, the position of moving objects can change substantially. The brain could use statistical regularities in the natural world to compensate neural delays and represent moving stimuli closer to real time. This possibility has been explored in the context of the flash lag illusion, where a briefly flashed stimulus in alignment with a moving one appears to lag behind the moving stimulus. Despite numerous psychophysical studies, the neural mechanisms underlying the flash lag illusion remain poorly understood, partly because it has never been studied electrophysiologically in behaving animals. Macaques are a prime model for such studies, but it is unknown if they perceive the illusion. By training monkeys to report their percepts unbiased by reward, we show that they indeed perceive the illusion qualitatively similar to humans. Importantly, the magnitude of the illusion is smaller in monkeys than in humans, but it increases linearly with the speed of the moving stimulus in both species. These results provide further evidence for the similarity of sensory information processing in macaques and humans and pave the way for detailed neurophysiological investigations of the flash lag illusion in behaving macaques.     

Molecular modeling of human neutral sphingomyelinase provides insight into its molecular interactions

The neutral sphingomyelinase (N-SMase) is considered a major candidate for mediating the stress-induced production of ceramide, and it plays an important role in cell-cycle arrest, apoptosis, inflammation, and eukaryotic stress responses. Recent studies have identified a small region at the very N-terminus of the 55 kDa tumour necrosis factor receptor (TNF-R55), designated the neutral sphingomyelinase activating domain (NSD) that is responsible for the TNF-induced activation of N-SMase. There is no direct association between TNF-R55 NSD and N-SMase; instead, a protein named factor associated with N-SMase activation (FAN) has been reported to couple the TNF-R55 NSD to N-SMase. Since the three-dimensional fold of N-SMase is still unknown, we have modeled the structure using the protein fold recognition and threading method. Moreover, we propose models for the TNF-R55 NSD as well as the FAN protein in order to study the structural basis of N-SMase activation and regulation. Protein-protein interaction studies suggest that FAN is crucially involved in mediating TNF-induced activation of the N-SMase pathway, which in turn regulates mitogenic and proinflammatory responses. Inhibition of N-SMase may lead to reduction of ceramide levels and hence may provide a novel therapeutic strategy for inflammation and autoimmune diseases. Molecular dynamics (MD) simulations were performed to check the stability of the predicted model and protein-protein complex; indeed, stable RMS deviations were obtained throughout the simulation. Furthermore, in silico docking of low molecular mass ligands into the active site of N-SMase suggests that His135, Glu48, Asp177, and Asn179 residues play crucial roles in this interaction. Based on our results, these ligands are proposed to be potent and selective N-SMase inhibitors, which may ultimately prove useful as lead compounds for drug development.     

Mechanisms of β-adrenergic receptors agonists in mediating pro and anti-apoptotic pathways in hyperglycemic Müller cells

Molecular Biology Reports - The current study aimed to investigate the stimulatory effect of beta-adrenergic receptors (β-ARs) on brain derived neurotropic factor (BDNF) and cAMP response...     

Methane and carbon dioxide emissions from inland waters in India – implications for large scale greenhouse gas balances

Inland waters were recently recognized to be important sources of methane (CH₄) and carbon dioxide (CO₂) to the atmosphere, and including inland water emissions in large scale greenhouse gas (GHG) budgets may potentially offset the estimated carbon sink in many areas. However, the lack of GHG flux measurements and well‐defined inland water areas for extrapolation, make the magnitude of the potential offset unclear. This study presents coordinated flux measurements of CH₄ and CO₂ in multiple lakes, ponds, rivers, open wells, reservoirs, springs, and canals in India. All these inland water types, representative of common aquatic ecosystems in India, emitted substantial amounts of CH₄ and a major fraction also emitted CO₂. The total CH₄ flux (including ebullition and diffusion) from all the 45 systems ranged from 0.01 to 52.1 mmol m^?2 d^?1, with a mean of 7.8 ± 12.7 (mean ± 1 SD) mmol m^?2 d^?1. The mean surface water CH₄ concentration was 3.8 ± 14.5 μm (range 0.03–92.1 μm ). The CO₂ fluxes ranged from ?28.2 to 262.4 mmol m^?2 d^?1 and the mean flux was 51.9 ± 71.1 mmol m^?2 d^?1. The mean partial pressure of CO₂ was 2927 ± 3269 μatm (range: 400–11 467 μatm). Conservative extrapolation to whole India, considering the specific area of the different water types studied, yielded average emissions of 2.1 Tg CH₄ yr^?1 and 22.0 Tg CO₂ yr^?1 from India's inland waters. When expressed as CO₂ equivalents, this amounts to 75 Tg CO₂ equivalents yr^?1 (53–98 Tg CO₂ equivalents yr^?1; ± 1 SD)_, with CH₄ contributing 71%. Hence, average inland water GHG emissions, which were not previously considered, correspond to 42% (30–55%) of the estimated land carbon sink of India. Thereby this study illustrates the importance of considering inland water GHG exchange in large scale assessments.     

Biochemical changes in kidneys of normal and stone forming rats with L(+)-tartrate

Influence of L(+)-tartrate was studied on certain enzymes, protein bound carbohydrates and lipids in the renal tissues of experimentally induced stone forming rats. The elevation in kidney LDH was moderate in the stone forming groups while tartrate had no effect. The significant increases in the activities of (Na+, K+)- and (Ca2+)-ATPases in the calculogenic group was lowered to that of normal level with tartrate administration. Acid phosphatase activity was significantly lowered in the tartrate treated groups. The significant reduction in phospholipids and elevation in sialic acid levels during stone formation are suggestive of minor alterations in the cellular structure. The changes in the transport ATPases is likely to affect the transport mechanism of nutrients and ions.     

Increased plasma lipidperoxidation in vitamin B-6 deficient rats

Lipidperoxidation in plasma of rats fed with vitamin B-6 deficient diet for a period of 12 weeks was studied with pair-fed controls. Plasma pyridoxal 5'-phosphate, alanine amino transferase and aspartate amino transferase, the markers of vitamin B-6 status, were significantly low in vitamin B-6 deficient rats. Plasma malondialdehyde level, conjugated dienes and lipofuscin like pigments were increased in vitamin B-6 deficiency. Increased levels of plasma lipids, calcium, iron and copper were observed in vitamin B-6 deficiency. Plasma susceptibility to lipidperoxidation was maximal in vitamin B-6 deficiency, upon stimulation by the promotors, Fe2+, Fe3+, Cu2+, ascorbate, t-butyl hydroperoxide and hydrogen peroxide.