Lipoic acid prevents liver metabolic changes induced by administration of a fructose-rich diet

Background

To evaluate whether co-administration of R/S-α-lipoic acid can prevent the development of oxidative stress and metabolic changes induced by a fructose-rich diet (F).

Methods

We assessed glycemia in the fasting state and during an oral glucose tolerance test, triglyceridemia and insulinemia in rats fed with standard diet (control) and fructose without or with R/S-α-lipoic acid. Insulin resistance and hepatic insulin sensitivity were also calculated. In liver, we measured reduced glutathione, protein carbonyl groups, antioxidant capacity by ABTS assay, antioxidant enzymes (catalase and superoxide dismutase 1 and 2), uncoupling protein 2, PPARδ and PPARγ protein expressions, SREBP-1c, fatty acid synthase and glycerol-3-phosphate acyltransferase-1 gene expression, and glucokinase activity.

Results

R/S-α-lipoic acid co-administration to F-fed rats a) prevented hyperinsulinemia, hypertriglyceridemia and insulin resistance, b) improved hepatic insulin sensitivity and glucose tolerance, c) decreased liver oxidative stress and increased antioxidant capacity and antioxidant enzymes expression, d) decreased uncoupling protein 2 and PPARδ protein expression and increased PPARγ levels, e) restored the basal gene expression of PPARδ, SREBP-1c and the lipogenic genes fatty acid synthase and glycerol-3-phosphate acyltransferase, and f) decreased the fructose-mediated enhancement of glucokinase activity.

Conclusions

Our results suggest that fructose-induced oxidative stress is an early phenomenon associated with compensatory hepatic metabolic mechanisms, and that treatment with an antioxidant prevented the development of such changes.

General significance

This knowledge would help to better understand the mechanisms involved in liver adaptation to fructose-induced oxidative stress and to develop effective strategies to prevent and treat, at early stages, obesity and type 2 diabetes mellitus.     

Mitochondrial DNA haplogroups and risk of new-onset diabetes among tacrolimus-treated renal transplanted patients

Background and aims

Tacrolimus (Tac) is an immunosuppressive drug widely used to avoid organ rejection. New-onset diabetes after transplantation (NODAT) is a major complication among transplanted patients who receive Tac. The increased risk for NODAT could be partly mediated by the effect of Tac on mitochondria from pancreatic beta-cells. Common and rare mitochondrial DNA variants have been linked to the risk of diabetes. Our aim was to determine whether mtDNA polymorphisms/haplogroups were associated with NODAT in Tac-treated kidney transplanted.

Methods

Seven polymorphisms that define the common European haplogroups were determined in 115 NODAT and 197 no-NODAT patients.

Results

Haplogroup H was significantly more frequent in the NODAT group (50% vs. 35%; p = 0.01, OR = 1.82). There was no difference between patients without and with (n = 106) D2M prior to the transplant.

Conclusions

Mitochondrial haplogroup H was associated with the risk for NODAT among Tac-treated transplanted patients. The reported differences between the mtDNA variants could explain the increased NODAT-risk among H-patients.     

Structural and functional characterization of simvastatin-induced myotoxicity in different skeletal muscles

Background

Statins are the most commonly used drugs for the treatment of hypercholesterolemia. Their most frequent side effect is myotoxicity. To date, it remains unclear whether statins preferentially induce myotoxicity in fast- or in slow-twitch muscles. Therefore, we investigated these effects on fast- (extensor digitorum longus; EDL), slow- (soleus; SOL), and mixed-twitch muscles (diaphragm; DIA) in rats by comparing their contractile and molecular structural properties.

Methods

Simvastatin-induced functional changes were determined by muscle contraction measurements, and drug-induced molecular changes were investigated using Fourier transform infrared (FTIR) and attenuated total reflectance (ATR) FTIR spectroscopy.

Results

With simvastatin administration (30 days, 50 mg/kg), a depression in the force–frequency curves in all muscles was observed, indicating the impairment of muscle contractility; however, the EDL and DIA muscles were affected more severely than the SOL muscle. Spectroscopic findings also showed a decrease in protein, glycogen, nucleic acid, lipid content and an increase in lipid order and lipid dynamics in the simvastatin-treated muscles. The lipid order and dynamics directly affect membrane thickness. Therefore, the kinetics and functions of membrane ion channels were also affected, contributing to the statin-induced impairment of muscle contractility. Furthermore, a reduction in α-helix and β-sheet and an increase in random coil, aggregated and antiparallel β-sheet were observed, indicating the protein denaturation. Spectral studies showed that the extent of molecular structural alterations in the muscles following simvastatin administration was in the order EDL > DIA > SOL.

Conclusions

Simvastatin-induced structural and functional alterations are more profound in the fast-twitch than in the slow-twitch muscles.

General significance

Myotoxic effects of simvastatin are primarily observed in the fast-twitch muscles.     

Stimulation of σ1-receptor restores abnormal mitochondrial Ca mobilization and ATP production following cardiac hypertrophy

Background

We previously reported that the σ₁-receptor (σ₁R) is down-regulated following cardiac hypertrophy and dysfunction in transverse aortic constriction (TAC) mice. Here we address how σ₁R stimulation with the selective σ₁R agonist SA4503 restores hypertrophy-induced cardiac dysfunction through σ₁R localized in the sarcoplasmic reticulum (SR).

Methods

We first confirmed anti-hypertrophic effects of SA4503 (0.1–1 μM) in cultured cardiomyocytes exposed to angiotensin II (Ang II). Then, to confirm the ameliorative effects of σ₁R stimulation in vivo, we administered SA4503 (1.0 mg/kg) and the σ₁R antagonist NE-100 (1.0 mg/kg) orally to TAC mice for 4 weeks (once daily).

Results

σ₁R stimulation with SA4503 significantly inhibited Ang II-induced cardiomyocyte hypertrophy. Ang II exposure for 72 h impaired phenylephrine (PE)-induced Ca^2 + mobilization from the SR into both the cytosol and mitochondria. Treatment of cardiomyocytes with SA4503 largely restored PE-induced Ca^2 + mobilization into mitochondria. Exposure of cardiomyocytes to Ang II for 72 h decreased basal ATP content and PE-induced ATP production concomitant with reduced mitochondrial size, while SA4503 treatment completely restored ATP production and mitochondrial size. Pretreatment with NE-100 or siRNA abolished these effects. Chronic SA4503 administration also significantly attenuated myocardial hypertrophy and restored ATP production in TAC mice. SA4503 administration also decreased hypertrophy-induced impairments in LV contractile function.

Conclusions

σ₁R stimulation with the specific agonist SA4503 ameliorates cardiac hypertrophy and dysfunction by restoring both mitochondrial Ca^2 + mobilization and ATP production via σ₁R stimulation.

General significance

Our observations suggest that σ₁R stimulation represents a new therapeutic strategy to rescue the heart from hypertrophic dysfunction.     

Association between genes encoding components of the IL-4/IL-4 receptor pathway and dermatitis in children

Objective

To determine whether IL-4, IL-4Rα and STAT6 polymorphisms are associated with susceptibility to dermatitis in Egyptian children.

Methods

We genotyped three groups of children, consisting of 106 atopic dermatitis (AD) children, 95 non-AD children, and 100 of healthy controls, for IL-4 (− 590 C/T), (− 33 C/T), IL-4Rα (I50V), (Q576R) and STAT6 (2964 G/A), (2892 C/T) gene polymorphisms using PCR-RFLP assay. Total serum IgE and serum IL-4 levels were detected by ELISA.

Results

There was a non-significant association of IL-4 − 590 C/T, − 33 C/T polymorphisms in the children with non-AD or those with AD when compared with the controls. We identified a significant association between IL-4Rα I50V, Q576R polymorphisms and dermatitis susceptibility in AD (p = 0.002, < 0.001 respectively), whereas no such association was observed in non-AD group (p = 0.52, 0.99 respectively). A significant association between STAT6 polymorphisms and both types of dermatitis was found. Patients who were carriers of IL4 − 590C, IL-4Rα I50V G, STAT6 2964 A and STAT6 2892 T had an increased risk of AD [OR and 95% CI: 3.2 (2.5–4.2), p = 0.005]. Furthermore, there was no relation between each polymorphism and serum IL-4 level (p > 0.05 for each) while homozygosity for the risk alleles of IL-4, IL-4Rα and STAT6 SNPs were significantly associated with increased total IgE levels in all subjects.

Conclusion

In Egyptian children, the IL-4Rα and the STAT6 polymorphism may play a role in susceptibility to AD. In addition, gene–gene interaction between the IL-4, the IL-4Rα and the STAT6 significantly increases an individual's susceptibility to AD.     

Stimulation of cytosolic and mitochondrial calcium mobilization by indomethacin in Caco-2 cells: Modulation by the polyphenols quercetin,resveratrol and rutin

Background

The effect of indomethacin (INDO) on Ca^2 + mobilization, cytotoxicity, apoptosis and caspase activation and the potential protective effect of quercetin (QUE), resveratrol (RES) and rutin (RUT) were determined in Caco-2 cells.

Methods

Caco-2 cells were incubated with INDO in the presence or absence of QUE, RES or RUT. The concentrations of Ca^2 + in the cytosol (Fluo-3 AM) and mitochondria (Rhod-2 AM) were determined as well as the cytotoxicity (MTT reduction and LDH leakage), apoptosis (TUNEL) and caspase-3 and 9 activities.

Results

INDO promoted Ca^2 + efflux from the endoplasmic reticulum (ER), resulting in an early, but transient, increment of cytosolic Ca^2 + at 3.5 min, followed by a subsequent increment of intra-mitochondrial Ca^2 + at 24 min. INDO also induced cytotoxicity, apoptosis, and increased caspase activities and cytochrome c release. All these alterations were prevented by the inhibitors of the IP3R and RyR receptors, 2-Aminoethoxydiphenyl borate (2-APB) and dantrolene. QUE was the most efficient polyphenol in preventing Ca^2 + mobilization induced by INDO and all of its consequences including cytotoxicity and apoptosis.

Conclusions

In Caco-2 cells, INDO stimulates ER Ca^2 + mobilization, probably through the activation of IP3R and RyR receptors, and the subsequent entry of Ca^2 + into the mitochondria. Polyphenols protected the cells against the Ca^2 + mobilization induced by INDO and its consequences on cytotoxicity and apoptosis.

General significance

These results confirm the possibility of using polyphenols and particularly QUE for the protection of the gastroduodenal mucosa in subjects consuming NSAIDs.     

Insulin sensitization via partial agonism of PPARγ and glucose uptake through translocation and activation of GLUT4 in PI3K/p-Akt signaling pathway by embelin in type 2 diabetic rats

Background

The present study was aimed at isolating an antidiabetic molecule from a herbal source and assessing its mechanism of action.

Methods

Embelin, isolated from Embelia ribes Burm. (Myrsinaceae) fruit, was evaluated for its potential to regulate insulin resistance, alter β-cell dysfunction and modulate key markers involved in insulin sensitivity and glucose transport using high-fat diet (HFD) fed-streptozotocin (STZ) (40 mg/kg)-induced type 2 diabetic rats. Molecular-dockings were performed to investigate the binding modes of embelin into PPARγ, PI3K, p-Akt and GLUT4 active sites.

Results

Embelin (50 mg/kg b wt.) reduced body weight gain, blood glucose and plasma insulin in treated diabetic rats. It further modulated the altered lipid profiles and antioxidant enzymes with cytoprotective action on β-cell. Embelin significantly increased the PPARγ expression in epididymal adipose tissue compared to diabetic control group; it also inhibited adipogenic activity; it mildly activated PPARγ levels in the liver and skeletal muscle. It also regulated insulin mediated glucose uptake in epididymal adipose tissue through translocation and activation of GLUT4 in PI3K/p-Akt signaling cascade. Embelin bound to PPARγ; it disclosed stable binding affinities to the active sites of PI3K, p-Akt and GLUT4.

Conclusions

These findings show that embelin could improve adipose tissue insulin sensitivity without increasing weight gain, enhance glycemic control, protect β-cell from damage and maintain glucose homeostasis in adipose tissue.

General significance

Embelin can be used in the prevention and treatment of type 2 diabetes mellitus caused due to obesity.     

Association between 1603C>T polymorphism of DBH gene and bipolar disorder in a Turkish population

Objectives

Dopamine-β-hydroxylase (DBH) is the enzyme responsible for the conversion of dopamine (DA) to norepinephrine (NE, noradrenaline) which is a key neurotransmitter in the central and peripheral nervous systems. Bipolar disorder is a major psychiatric disorder. The present study was designed to explore the associations of polymorphisms of DBH gene in Turkish patients with bipolar disorder.

Methods

− 1021C>T (rs1611115) polymorphism in promoter region, 444G>A (rs1108580) polymorphism in exon 2 and 1603C>T (rs6271; C535R) polymorphism in exon11 of DBH gene were analyzed in 106 patients with bipolar disorder and 106 healthy subjects by using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis.

Results

The results showed statistically significant associations for genotypic and allelic distribution between the 1603C>T polymorphism and bipolar disease (p = 0.0012 and p = 0.034, respectively). There was no association observed between the genotype and allelic frequencies for − 1021C>T and 444G>A polymorphisms and bipolar disorder.

Conclusions

Our data suggests that the 1603C>T polymorphism of the DBH gene is associated with susceptibility to bipolar disorder in a Turkish population.     

Association of P213S polymorphism of the L-selectin gene with type 2 diabetes and insulin resistance in Chinese population

Aims

L-selectin belongs to selectin family of adhesion molecule and participates in the generation and development of type 2 diabetes (T2D). In this study, we evaluated the relationship between the P213S polymorphism of L-selectin gene and T2D and insulin resistance in the Chinese population.

Methods

We genotyped P213S polymorphism in 801 patients with T2D and 834 healthy controls in the Chinese population using polymerase chain reaction–ligase detection reaction (PCR–LDR) technique. Plasma glucose, insulin, lipid, blood urea nitrogen, creatinine and uric acid levels were measured by biochemical technique.

Results

The frequency of 213PP genotype and P allele of the L-selectin gene in patients with T2D was significantly higher than that in controls (P = 0.007; P = 0.019, respectively). The relative risk of allele P suffered from T2D was 1.191 times higher than that of allele S. Moreover, the levels of FPG and HOMA-IR of PP and PS genotype carriers were significantly higher than those of SS genotype carriers in the T2D group (P < 0.05).

Conclusion

These findings indicated that the P213S polymorphism of L‐selectin gene may contribute to susceptibility to T2D and insulin resistance in the Chinese population, and P allele appears to be a risk factor for T2D.     

A mutation associated with centronuclear myopathy enhances the size and stability of dynamin 2 complexes in cells

Background

Dynamin 2 (Dyn2) is a ~ 100 kDa GTPase that assembles around the necks of nascent endocytic and Golgi vesicles and catalyzes membrane scission. Mutations in Dyn2 that cause centronuclear myopathy (CNM) have been shown to stabilize Dyn2 polymers against GTP-dependent disassembly in vitro. Precisely timed regulation of assembly and disassembly is believed to be critical for Dyn2 function in membrane vesiculation, and the CNM mutations interfere with this regulation by shifting the equilibrium toward the assembled state.

Methods

In this study we use two fluorescence fluctuation spectroscopy (FFS) approaches to show that a CNM mutant form of Dyn2 also has a greater propensity to self-assemble in the cytosol and on the plasma membrane of living cells.

Results

Results obtained using brightness analysis indicate that unassembled wild-type Dyn2 is predominantly tetrameric in the cytosol, although different oligomeric species are observed, depending on the concentration of expressed protein. In contrast, an R369W mutant identified in CNM patients forms higher-order oligomers at concentrations above 1 μM. Investigation of Dyn2-R369W by Total Internal Reflection Fluorescence (TIRF) FFS reveals that this mutant forms larger and more stable clathrin-containing structures on the plasma membrane than wild-type Dyn2.

Conclusions and general significance

These observations may explain defects in membrane trafficking reported in CNM patient cells and in heterologous systems expressing CNM-associated Dyn2 mutants.     

Up-regulation of adenylylcyclases I and II induced by long-term adaptation of rats to morphine fades away 20 days after morphine withdrawal

Background

Activation of adenylyl cyclase (AC) by prolonged exposure of mammalian organism to morphine was demonstrated in previous studies of mechanism of action of this drug. However, expression level of individual AC isoforms was not analyzed in crucial cell structure, plasma membrane (PM).

Methods

Rats were adapted to morphine for 10 days and sacrificed 24 h (group + M10) or 20 days (+ M10/−M20) after the last dose. Control animals were sacrificed in parallel with morphine-treated (groups − M10 and (− M10/−M20)). Percoll®-purified PM were isolated from brain cortex and analyzed by immunoblotting and specific radioligand binding.

Results

ACI (ACII) was increased 8× (2.5×) in morphine-adapted rats (+ M10) when compared with controls (− M10). Increase of ACI and II by long-term adaptation to increasing doses of morphine represented a specific effect as the amount of ACIII–ACIX, of prototypical PM marker, Na, K-ATPase and of trimeric G protein α and β subunits was unchanged. Increase of ACI and II was not detected in PM isolated from group (+ M10/−M20). Thus, the marked increase of ACI and ACII faded away 20 days since the last dose of morphine.

Conclusions

We assume that the specific increase in expression level of ACI and ACII in brain cortex of morphine-adapted rats proceeds as a compensatory, homeostatic response to prolonged exposure to inhibitory drug, morphine.

General significance

Our findings demonstrate that the dramatic and specific change of the crucial component of the opioid receptor cascade in brain cortex, manifested as an increase in PM level of ACI and II, is reversible.     

Mitochondrial DNA mutations in diabetes mellitus patients in Chinese Han population

Background and objective

Mutations of mitochondrial DNA are associated with diabetes mellitus (DM). The present case–control study aimed to investigate the mutations of mitochondrial DNA in DM patients of Chinese Han ethnicity.

Methods and results

A total of 770 DM patients and 309 healthy control individuals were enrolled. The mitochondrial DNA was extracted from blood cells and analyzed by the polymerase chain reaction–restriction fragment length polymorphism assay. In the diabetes group, there were 13 (1.69%) individuals carrying the mt3243 A → G mutation while none of the healthy control had this mutation. Though the 14709, 3316, 3394, and 12026 mutation variants were identified in 9, 17, 18 and 28 in DM patients respectively, there were no significant differences compared with control group. And the 3256, 8296, 8344, 8363, 3426 and 12258 mutations were not detected in either group. In the diabetes group, two double mutations were identified: A3243G+T3394C and A3243G+A12026G.

Conclusion

Our data suggested that mitochondrial gene tRNA^Leu(UUR) 3243 A → G mutation may be one risk of prevalence of DM and associated with worse clinical status in Chinese Han population.     

Development of peptide inhibitor as a therapeutic agent against head and neck squamous cell carcinoma (HNSCC) targeting p38α MAP kinase

Background

The p38α MAP kinase pathway is involved in inflammation, cell differentiation, growth, apoptosis and production of pro-inflammatory cytokines TNF-α and IL-1β. The overproduction of these cytokines plays an important role in cancer. The aim of this work was to design a peptide inhibitor on the basis of structural information of the active site of p38α.

Methods

A tetrapeptide, VWCS as p38α inhibitor was designed on the basis of structural information of the ATP binding site by molecular modeling. The inhibition study of peptide with p38α was performed by ELISA, binding study by Surface Plasmon Resonance and anti-proliferative assays by MTT and flow cytometry.

Results

The percentage inhibition of designed VWCS against pure p38α protein and serum of HNSCC patients was 70.30 and 71.5%, respectively. The biochemical assay demonstrated the K_D and IC₅₀ of the selective peptide as 7.22 × 10^− 9 M and 20.08 nM, respectively. The VWCS as inhibitor significantly reduced viability of oral cancer KB cell line with an IC₅₀ value of 10 μM and induced apoptosis by activating Caspase 3 and 7.

Conclusions

VWCS efficiently interacted at the ATP binding pocket of p38α with high potency and can be used as a potent inhibitor in case of HNSCC.

General significance

VWCS can act as an anticancer agent as it potentially inhibits the cell growth and induces apoptosis in oral cancer cell-line in a dose as well as time dependent manner. Hence, p38α MAP kinase inhibitor can be a potential therapeutic agent for human oral cancer.     

Association of heat shock protein70-2 (HSP70-2) gene polymorphism with coronary artery disease in an Iranian population

Background

Coronary artery disease (CAD) is an inflammatory process and a major cause of mortality and morbidity. The (heat shock protein70-2) HSP70-2 gene is reported to be associated with coronary artery disease possibly by affecting the regulation of pro-inflammatory cytokines such as TNF-α. The association between CAD and the HSP70-2 gene + 1267A>G polymorphism has been studied in some populations but there are no data about this association in the Iranian population.

Aim

We have investigated the association between the HSP70-2 gene + 1267A>G polymorphism and angiographically defined CAD within an Iranian population.

Methods

We determined the presence of the HSP70-2 gene + 1267A>G polymorphism in 628 patients with CAD and 307 healthy individuals using PCR-RFLP. Of the patients, 433 (68%) had > 50% stenosis (CAD +) and the remaining 195 patients had < 50% stenosis (CAD −), based on coronary angiography. Angiogram positive patients were subdivided into three groups: those with single (n = 113), double (n = 134), and triple vessels (n = 186) disease.

Results

A significant higher frequency of AG + GG genotypes (G allele carriers) was observed in angiogram positive and angiogram negative groups compared to controls in a dominant analysis model of the HSP70-2 gene + 1267A>G position (51.2 vs. 43.2, P = 0.002, OR = 1.37) (51.0 vs. 43.2, P = 0.01, OR = 1.37). The allele frequency of the HSP70-2 G was also significantly higher in angiogram positive and angiogram negative groups compared to the control group (51.2 vs. 43.2, P = 0.002, OR = 1.37) (51.0 vs. 43.2, P = 0.01, OR = 1.37).

Conclusion

These results suggest that HSP70-2 + 1267 polymorphism may influence the risk of CAD in Iranian population, however further studies are needed to clarify the role of other HSP70-2 gene polymorphisms in the pathogenesis of the CAD.     

Selective cytotoxicity of intense nanosecond-duration electric pulses in mammalian cells

Background

Nanosecond electric pulses (EP) disrupt cell membrane and organelles and cause cell death in a manner different from the conventional irreversible electroporation. We explored the cytotoxic effect of 10-ns EP (quantitation, mechanisms, efficiency, and specificity) in comparison with 300-ns, 1.8- and 9-μs EP.

Methods

Effects in Jurkat and U937 cells were characterized by survival assays, DNA electrophoresis and flow cytometry.

Results

10-ns EP caused apoptotic or necrotic death within 2–20 h. Survival (S, %) followed the absorbed dose (D, J/g) as: S = αD^(−K), where coefficients K and α determined the slope and the “shoulder” of the survival curve. K was similar in all groups, whereas α was cell type- and pulse duration-dependent. Long pulses caused immediate propidium uptake and phosphatidylserine (PS) externalization, whereas 10-ns pulses caused PS externalization only.

Conclusions

1.8- and 9-μs EP cause cell death efficiently and indiscriminately (LD₅₀ 1–3 J/g in both cell lines); 10-ns EP are less efficient, but very selective (LD₅₀ 50–80 J/g for Jurkat and 400–500 J/g for U937); 300-ns EP show intermediate effects. Shorter EP open propidium-impermeable, small membrane pores (”nanopores”), triggering different cell death mechanisms.

General significance

Nanosecond EP can selectively target certain cells in medical applications like tumor ablation.     

Association between resistin + 299A/A genotype and nonalcoholic fatty liver disease in Chinese patients with type 2 diabetes mellitus

Objective

To investigate the relationship between the resistin intronic + 299G/A polymorphism and nonalcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM).

Methods

We selected 738 T2DM patients, including 395 with NAFLD and 343 without fatty liver disease, as well as 279 healthy control individuals, and analyzed their resistin + 299G/A polymorphism genotype by polymerase chain reaction–restriction fragment length polymorphism.

Results

Plasma resistin levels in T2DM patients with NAFLD were at the highest (P < 0.05). The frequency of AA genotype at the + 299 site of the resistin gene in patients with concurrent T2DM combined with NAFLD was significantly different from that in the control (P < 0.05). The AA genotype was found to be associated with a 1.80-fold increased risk for T2DM combined with NAFLD, 2.05-fold increased risk for obesity and 2.37-fold increased risk for obesity of abdominal type compared to the GG (P < 0.05, respectively). The multivariate non-conditional logistic regression model analysis further shows that the AA genotype is a risk factor for the development of NAFLD in T2DM patients (OR, 2.32; 95% CI, 1.05–4.68; P < 0.05).

Conclusion

The resistin + 299AA genotype may be associated with increases in the risk of the NAFLD development in T2DM patients.     

Genetic variants in epoxide hydrolases modify the risk of oligozoospermia and asthenospermia in Han-Chinese population

Objectives

Epoxide hydrolases are involved in detoxifying and excreting the environmental chemicals, which are associated with decreased semen quality and male infertility. We hypothesized that polymorphisms in epoxide hydrolases may be associated with risk of oligozoospermia and asthenospermia.

Design and methods

In this study, 468 fertile controls and 672 idiopathic male infertile patients were recruited. SNPstream and TaqMan assay were used to genotype four single nucleotide polymorphisms in EPHX1 and EPHX2. The semen analysis was performed by computer-assisted semen analysis system.

Results

Our results demonstrated that rs1042064 of EPHX2 was significantly associated with decreased risk of oligozoospermia (OR = 0.65, 95% CI: 0.44–0.98) and asthenospermia (OR = 0.66, 95% CI: 0.46–0.94).

Conclusions

Our results provided evidence that genetic variants in epoxide hydrolases may modify the risk of oligozoospermia and asthenospermia in Han-Chinese population.     

Association between the ghrelin Leu72Met polymorphism and type 2 diabetes risk: A meta-analysis

Aims

Data on the association between the ghrelin Leu72Met polymorphism and type 2 diabetes are conflicting. A meta-analysis was performed on this topic.

Methods

We searched for case–control studies using electronic databases (Medline and PubMed) and reference lists of studies. Odds ratios (OR) and 95% confidence intervals (CI) assuming dominant, recessive and homozygote comparison genetic models were calculated.

Results

Six case–control studies involving a total of 3417 cases and 3081 controls were included in this meta-analysis. No association was found between the ghrelin Leu72Met polymorphism and type 2 diabetes risk in the overall population in dominant, recessive and homozygote comparison models. However, in subgroup analyses stratified by ethnicity, we found that the risk for type 2 diabetes was decreased in subjects with Met72 + genotypes in Caucasians (OR = 0.79, 95% CI: 0.64–0.98, P_z = 0.030).

Conclusion

The ghrelin Leu72Met polymorphism was protective against type 2 diabetes in Caucasians. Future studies performed in larger sample size are needed to allow a more definitive conclusion.