High phosphate feeding induced arterial medial calcification in uremic rats: Roles of Lanthanum carbonate on protecting vasculature

Aims

High cardiovascular mortality in patients with end-stage renal disease is closely associated with arterial medial calcification (AMC) caused by hyperphosphatemia, the mechanism of which associated hormones (FGF-23, klotho) and osteochondrogenic events is unclear. We examined the effect of Lanthanum carbonate on AMC via regulating the abnormalities in phosphorus metabolism of uremic rats.

Main methods

45 healthy SD rats were randomly divided into 3 groups: Normal group (n = 15), CRF group (n = 15), CRF diet supplemented with 2% La (n = 15). AMC in great arteries were evaluated by VonKossa. Osteochondrogenic specific genes were analyzed by Immunohistochemistry and qRT-PCR. Serum FGF-23 and klotho levels were detected by ELISA kit.

Key findings

Serum phosphate was markedly increased in CRF group (6.94 ± 0.97 mmol/L) and 2%La group (5.12 ± 0.84 mmol/L) at week 4, while the latter became hypophosphatemic (2.92 ± 0.73 mmol/L vs CRF group, p < 0.01) at week 10. Inhibitory effect of 2%La on development of AMC was reflected by downregulated Runx2, Osterix, BSP, Osteocalcin and collagenII and a reduction of FGF-23 at week 4(vs CRF group, p < 0.01) but not week 10.

Significance

Beneficial effects of Lanthanum carbonate on progression of AMC in CRF could be mainly due to the decreased phosphate retention and FGF-23 in early stage and likewise a reduction of bone-associated proteins via osteochondrogenic pathway. Lanthanum carbonate has no effect on soluble klotho and serum FGF-23 in late stage of CRF.     

Klotho gene polymorphism of rs3752472 is associated with the risk of urinary calculi in the population of Han nationality in Eastern China

Background/aims

The incidence of urolithiasis has considerably increased throughout the world in the last two decades. Clinical researches have showed an association between oxidative stress and stone formation. Emerging evidence indicated a novel function for klotho protein in anti-oxidative stress. In this study, we aimed at investigating a possible relationship between klotho gene polymorphisms and the risk of calcium oxalate urolithiasis in the population of Han nationality in Eastern China.

Methods

Klotho gene polymorphisms rs3752472 in exon3, rs650439 in intron 4 and rs577912 in intron 1 were investigated in 426 patients with calcium oxalate stones compared with 282 age-matched healthy volunteers with no history of stone formation, using TaqMan SNP Genotyping Assays.

Results

Significant differences were found between rs3752472 and the risk of nephrolithiasis as CC genotype of rs3752472 klotho polymorphism had almost 2-fold increased stone risk compared with the heterozygote genotype CT and homozygous genotype TT(95% CI = 1.013–2.255, OR = 1.512,p = 0.043).

Conclusion

Our results showed that the rs3752472 polymorphism of klotho gene is associated with the risk of calcium oxalate urolithiasis and may act as a risk factor during stone formation in our study population.     

Enzymatic analysis of biomarkers for the monitoring of Gaucher patients in Colombia

Introduction

Gaucher disease is caused by a deficiency of the enzyme acid beta-glucosidase. There is treatment available, but given the wide variability in phenotypes, it is difficult to establish the adequate administration and change of doses. Chitotriosidase and angiotensin converting enzyme (ACE) have been described as reliable biomarkers for the monitoring of patients. The enzymatic evaluation of these biomarkers has been traditionally made in serum or plasma samples, making difficult the monitoring of Colombian patients who live far away from big cities. Dried blood spot samples have been proposed as a solution. The aim of the present study was to validate the chitotriosidase quantification in DBS with respect to the serum determination, and to standardize a microtechnique for the quantification of serum ACE.

Results

Using a fluorometric method for the chitotriosidase quantification and a colorimetric one for ACE determinations, we found significant differences between control subjects and Gaucher patients in both serum and DBS samples. A positive correlation was observed between both kinds of samples. A reference value for the ACE determination was established. A positive correlation between chitotriosidase and ACE was found.

Conclusion

We could standardize two microtechniques for chitotriosidase and ACE analysis in serum samples. A close relation between DBS and serum samples for chitotriosidase analysis allowed us to validate DBS as a reliable sample that could facilitate the access of Colombian Gaucher patients to health services.     

Calorimetric analysis of the plasma proteome: Identification of type 1 diabetes patients with early renal function decline

Background

Microalbuminuria (MA) has been questioned as a predictor of progressive renal dysfunction in patients with type 1 diabetes (T1D). Consequently, new clinical end points are needed that identify or predict patients that are at risk for early renal function decline (ERFD). The potential clinical utility of differential scanning calorimetry (DSC) analysis of blood plasma and other biofluids has recently been reported. This method provides an alternate physical basis with which to study disease-associated changes in the bulk plasma proteome.

Methods

DSC analysis of blood plasma was applied to identify unique signatures of ERFD in subjects enrolled in the 1st Joslin Study of the Natural History of Microalbuminuria in Type 1 Diabetes, a prospective cohort study of T1D patients. Recent data suggests that differences in the plasma peptidome of these patients correlate with longitudinal measures of renal function. Differences in DSC profile (thermogram) features were evaluated between T1D MA individuals exhibiting ERFD (n = 15) and matched control subjects (n = 14).

Results

The average control group thermogram resembled a previously defined healthy thermogram. Differences were evident between ERFD and control individuals. Heat capacity values of the main two transitions were found to be significant discriminators of patient status.

Conclusions

Results from this pilot study suggest the potential utility of DSC proteome analysis to prognostic indicators of renal disease in T1D.

General significance

DSC shows sensitivity to changes in the bulk plasma proteome that correlate with clinical status in T1D providing additional support for the utility of DSC profiling in clinical diagnostics.     

Association between interleukin 4 gene intron 3 VNTR polymorphism and recurrent aphthous stomatitis in a cohort of Turkish patients

Objective

Recurrent aphthous stomatitis (RAS) is one of the most common oral mucosal diseases, with a multifactorial etiopathogenesis, an interaction between predisposing factors and/or systemic conditions and immunological components in genetically predisposed subjects. Although there is no clear genetic mode of inheritance, there is evidence that inheritance of specific gene polymorphisms may predispose individuals to RAS. The purpose of the present study was to investigate a possible association between the functional interleukin 4 (IL4) VNTR genetic polymorphism and RAS in a sample of Turkish patients.

Methods

The study included 145 unrelated patients with a clinical diagnosis of RAS and 150 unrelated healthy controls. Genomic DNA was isolated and IL4 gene 70 bp VNTR polymorphism determined by using polymerase chain reaction (PCR) with specific primers.

Results

The distribution of genotype and allele frequencies of IL4 gene intron 3 VNTR polymorphism was statistically different between RAS patients and control group (p < 0.0001 and p < 0.0001, respectively) P2P2 genotype and P2 allele were also found to be protective with a lower risk for susceptibility to RAS (p < 0.0001).

Conclusion

The results of this study suggest that intron 3 VNTR polymorphism in the IL4 gene is associated with RAS susceptibility in Turkish population.     

Identification of prohibitin as an antigen in Behcet’s disease

Objective

This study is intended to screen potential antigen for Behcet’s disease (BD) by using human microvascular endothelial cells (HUVEC).

Methods

Following cell-based indirect immunofluorescence assay with sera from BD patients, proteins extracted from HUVEC were separated and detected by Western blotting. Then the target protein was identified by LC-MALDI-TOF/TOF, the recombinant target protein was expressed, purified and then used as coating antigen to test the prevalence of autoantibodies in patient’s sera.

Results

The Western blotting result showed that some patients’ sera could react with a protein band with about 30 kDa of molecular weight, which was further identified as prohibitin by mass spectrometry. The prevalence of serum antibodies against recombinant human prohibitin was detected in 16 of 58 BD patients (28%) but none in healthy controls.     

In vivo enzymatic activity of acetylCoA synthetase in skeletal muscle revealed by C turnover from hyperpolarized [1-C]acetate to [1-C]acetylcarnitine

Background

Acetate metabolism in skeletal muscle is regulated by acetylCoA synthetase (ACS). The main function of ACS is to provide cells with acetylCoA, a key molecule for numerous metabolic pathways including fatty acid and cholesterol synthesis and the Krebs cycle.

Methods

Hyperpolarized [1-¹³C]acetate prepared via dissolution dynamic nuclear polarization was injected intravenously at different concentrations into rats. The ¹³C magnetic resonance signals of [1-¹³C]acetate and [1-¹³C]acetylcarnitine were recorded in vivo for 1 min. The kinetic rate constants related to the transformation of acetate into acetylcarnitine were deduced from the 3 s time resolution measurements using two approaches, either mathematical modeling or relative metabolite ratios.

Results

Although separated by two biochemical transformations, a kinetic analysis of the ¹³C label flow from [1-¹³C]acetate to [1-¹³C]acetylcarnitine led to a unique determination of the activity of ACS. The in vivo Michaelis constants for ACS were K_M = 0.35 ± 0.13 mM and V_max = 0.199 ± 0.031 μmol/g/min.

Conclusions

The conversion rates from hyperpolarized acetate into acetylcarnitine were quantified in vivo and, although separated by two enzymatic reactions, these rates uniquely defined the activity of ACS. The conversion rates associated with ACS were obtained using two analytical approaches, both methods yielding similar results.

General significance

This study demonstrates the feasibility of directly measuring ACS activity in vivo and, since the activity of ACS can be affected by various pathological states such as cancer or diabetes, the proposed method could be used to non-invasively probe metabolic signatures of ACS in diseased tissue.     

A spectrum of novel NPHS1 and NPHS2 gene mutations in pediatric nephrotic syndrome patients from Pakistan

Background

Mutations in the NPHS1 and NPHS2 genes are among the main causes of early-onset and familial steroid resistant nephrotic syndrome respectively. This study was carried out to assess the frequencies of mutations in these two genes in a cohort of Pakistani pediatric NS patients.

Methods

Mutation analysis was carried out by direct sequencing of the NPHS1 and NPHS2 genes in 145 nephrotic syndrome (NS) patients. This cohort included 36 samples of congenital or infantile onset NS cases and 39 samples of familial cases obtained from 30 families.

Results

A total of 7 homozygous (6 novel) mutations were found in the NPHS1 gene and 4 homozygous mutations in the NPHS2 gene. All mutations in the NPHS1 gene were found in the early onset cases. Of these, one patient has a family history of NS. Homozygous p.R229Q mutation in the NPHS2 gene was found in two children with childhood-onset NS.

Conclusions

Our results show a low prevalence of disease causing mutations in the NPHS1 (22% early onset, 5.5% overall) and NPHS2 (3.3% early onset and 3.4% overall) genes in the Pakistani NS children as compared to the European populations. In contrast to the high frequency of the NPHS2 gene mutations reported for familial SRNS in Europe, no mutation was found in the familial Pakistani cases. To our knowledge, this is the first comprehensive screening of the NPHS1 and NPHS2 gene mutations in sporadic and familial NS cases from South Asia.     

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.     

Monogalactosyl diacylglycerol,a replicative DNA polymerase inhibitor,from spinach enhances the anti-cell proliferation effect of gemcitabine in human pancreatic cancer cells

Background

Gemcitabine (GEM) is used to treat various carcinomas and represents an advance in pancreatic cancer treatment. In the screening for DNA polymerase (pol) inhibitors, a glycoglycerolipid, monogalactosyl diacylglycerol (MGDG), was isolated from spinach.

Methods

Phosphorylated GEM derivatives were chemically synthesized. In vitro pol assay was performed according to our established methods. Cell viability was measured using MTT assay.

Results

Phosphorylated GEMs inhibition of mammalian pol activities assessed, with the order of their effect ranked as: GEM-5′-triphosphate (GEM-TP) > GEM-5′-diphosphate > GEM-5′-monophosphate > GEM. GEM suppressed growth in the human pancreatic cancer cell lines BxPC-3, MIAPaCa2 and PANC-1 although phosphorylated GEMs showed no effect. MGDG suppressed growth in these cell lines based on its selective inhibition of replicative pol species. Kinetic analysis showed that GEM-TP was a competitive inhibitor of pol α activity with nucleotide substrates, and MGDG was a noncompetitive inhibitor with nucleotide substrates. GEM combined with MGDG treatments revealed synergistic effects on the inhibition of DNA replicative pols α and γ activities compared with GEM or MGDG alone. In cell growth suppression by GEM, pre-addition of MGDG significantly enhanced cell proliferation suppression, and the combination of these compounds was found to induce apoptosis. In contrast, GEM-treated cells followed by MGDG addition did not influence cell growth.

Conclusions

GEM/MGDG enhanced the growth suppression of cells based on the inhibition of pol activities.

General significance

Spinach MGDG has great potential for development as an anticancer food compound and could be an effective clinical anticancer chemotherapy in combination with GEM.     

DNA-maleimide: An improved maleimide compound for electrophoresis-based titration of reactive thiols in a specific protein

Background

Thiol-mediated redox regulation of proteins plays a key role in many cellular processes.

Methods

To understand the redox status of cysteinyl thiol groups of the desired proteins, we developed a new maleimide reagent: a maleimide-conjugated single strand DNA, DNA-maleimide (DNA-Mal).

Results

DNA-Mal labelled proteins run as a distinct band on SDS-PAGE, with a discrete 9.32 kDa mobility shift per label regardless of the protein species or electrophoretic conditions.

Conclusions

DNA-Mal labels free thiols like standard maleimide reagents, but possesses practical advantages in titration of the number and relative content of free thiols in a protein.

General significance

The versatility of DNA molecule enhances the application of DNA-Mal in a broader range of cysteine containing proteins.     

Moderate concentrations of 4-O-methylhonokiol potentiate GABAA receptor currents stronger than honokiol

Background

Magnolia bark preparations from Magnolia officinalis of Asian medicinal systems are known for their muscle relaxant effect and anticonvulsant activity. These CNS related effects are ascribed to the presence of the biphenyl-type neolignans honokiol and magnolol that exert a potentiating effect on GABA_A receptors. 4-O-methylhonokiol isolated from seeds of the North-American M. grandiflora was compared to honokiol for its activity to potentiate GABA_A receptors and its GABA_A receptor subtype-specificity was established.

Methods

Different recombinant GABA_A receptors were functionally expressed in Xenopus oocytes and electrophysiological techniques were used determine to their modulation by 4-O-methylhonokiol.

Results

3 μM 4-O-methylhonokiol is shown here to potentiate responses of the α₁β₂γ₂ GABA_A receptor about 20-fold stronger than the same concentration of honokiol. In the present study potentiation by 4-O-methylhonokiol is also detailed for 12 GABA_A receptor subtypes to assess GABA_A receptor subunits that are responsible for the potentiating effect.

Conclusion

The much higher potentiation of GABA_A receptors at identical concentrations of 4-O-methylhonokiol as compared to honokiol parallels previous observations made in other systems of potentiated pharmacological activity of 4-O-methylhonokiol over honokiol.

General significance

The results point to the use of 4-O-methylhonokiol as a lead for GABA_A receptor potentiation and corroborate the use of M. grandiflora seeds against convulsions in Mexican folk medicine.     

Expression of bone morphogenetic protein 4 and its receptors in the remodeling heart

Aims

Heart failure is associated with activation of fetal gene programs. Bone morphogenetic proteins (BMPs) regulate embryonic development through interaction with BMP receptors (BMPRs) on the cell surface. We investigated if the expression of BMP4 and its receptors BMPR1a and BMPR2 were activated in post-infarction remodeling and heart failure.

Main methods

Left ventricular biopsies were taken from explanted hearts of patients with end-stage heart failure due to dilated cardiomyopathy (CMP; n = 15) or ischemic heart disease (CAD; n = 9), and compared with homograft control preparations from organ donors deceased due to non-cardiac causes (n = 7). Other samples were taken from patients undergoing coronary artery bypass grafting (CABG; n = 11). Mice were subjected to induced infarction by permanent coronary artery ligation or sham operation, and hearts were sampled serially thereafter (n = 7 at each time point).

Key findings

Human and mouse hearts expressed BMP4 and both receptor subtypes. CABG and CMP patients had increased expression of mRNA encoding for BMP4, but unchanged protein. Mouse hearts had increased BMP4 precursor protein 24 h after infarction. BMPR1a protein decreased in CAD patients and initially in postinfarcted mouse hearts, but increased again in the latter after two weeks. Human recombinant BMP4 promoted survival after H₂O₂ injury in HL-1 cells, and also protected adult mouse cardiomyocytes against hypoxia–reoxygenation injury.

Significance

Adult hearts express BMP4, the mRNA increasingly so in patients with coronary artery disease with good cardiac function. BMPRs are downregulated in cardiac remodeling and failure. Recombinant BMP4 has protective effects on cultured cardiomyocytes.     

A single-nucleotide polymorphism in tumor necrosis factor-α (− 308 G/A) as a biomarker in chronic pancreatitis

Objective

Chronic pancreatitis is a gradual, long-term inflammation of the pancreas that results in alteration of its normal structure and function. The study aims to investigate the role of − 308 (G/A) polymorphism of TNF-α gene in chronic pancreatitis.

Material and methods

A total of 200 subjects were included in this case–control study. A total of 100 in patients admitted in the Gastroenterology Unit of Gandhi Hospital and Osmania General Hospital, Hyderabad were included in the present study. An equal number of healthy control subjects were randomly selected for the study. The genotyping of TNF-α gene was carried out by tetra-primer ARMS PCR followed by gel electrophoresis. The TNF-α levels were assayed by enzyme-linked immunosorbent assay.

Results

A significant variation with respect to the genotypic and allelic distribution in the disease group when compared to control subjects [OR = 2.001 (1.33–3.005), p < 0.0001**] was observed. Subjects homozygous for the A allele had higher TNF-α levels compared to G allele.

Conclusion

The present study revealed a significant association of the TNF-α gene promoter polymorphism with chronic pancreatitis. Thus, TNF-α genotype can be considered as one of the biological markers in the etiology of chronic pancreatitis.     

Glutamate transporter type 3 regulates mouse hippocampal GluR1 trafficking

Background

Rapid trafficking of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) to the plasma membrane is considered a fundamental biological process for learning and memory. GluR1 is an AMPAR subunit. We have shown that mice with knockout of excitatory amino acid transporter type 3 (EAAT3), a neuronal glutamate transporter, have impaired learning and memory. The mechanisms for this impairment are not known and may be via regulation of AMPAR trafficking.

Methods

Freshly prepared 300 μm coronal hippocampal slices from wild-type or EAAT3 knockout mice were incubated with or without 25 mM tetraethylammonium for 10 min. The trafficking of GluR1, an AMPAR subunit, to the plasma membrane and its phosphorylation were measured.

Results

Tetraethylammonium increased the trafficking of GluR1 and EAAT3 to the plasma membrane in the wild-type mouse hippocampal slices but did not cause GluR1 trafficking in the EAAT3 knockout mice. Tetraethylammonium also increased the phosphorylation of GluR1 at S845, a protein kinase A (PKA) site, in the wild-type mice but not in the EAAT3 knockout mice. The PKA antagonist KT5720 attenuated tetraethylammonium-induced GluR1 phosphorylation and trafficking in the wild-type mice. The PKA agonist 6-BNz-cAMP caused GluR1 trafficking to the plasma membrane in the EAAT3 knockout mice. In addition, EAAT3 was co-immunoprecipitated with PKA.

Conclusions

These results suggest that EAAT3 is upstream of PKA in a pathway to regulate GluR1 trafficking.

General significance

Our results provide initial evidence for the involvement of EAAT3 in the biochemical cascade of learning and memory.     

4-Phenylbutyric acid suppresses inflammation through regulation of endoplasmic reticulum stress of endothelial cells stimulated by uremic serum

Aims

Endoplasmic reticulum (ER) stress is involved in the pathogenesis of atherosclerosis (AS). Endothelial cell (EC) dysfunction and monocyte migration to the subendothelium are considered to be essential manifestations of AS. We conducted this study to determine whether ER stress was involved in uremic serum-induced EC dysfunction and whether the regulation of ER stress using a chemical chaperone 4-phenylbutyric acid (4-PBA) had a preventative effect.

Main methods

Human umbilical vein endothelial cells (HUVECs) were divided into 4 groups: a control serum group (C.S), a uremic serum group (U.S), a uremic serum plus 4-PBA (5 mM) treatment group (4-PBA), and a uremic serum plus pyrrolidine dithiocarbamate (PDTC:50 μM) treatment group (PDTC).

Key findings

Lower concentrations of uremic serum (< 10%) facilitated the proliferation of HUVECs. In contrast, the proliferative capability of HUVECs was gradually decreased when we continuously increased the concentration of uremic serum. Compared with C.S, HUVEC incubation with uremic serum had high expression levels of GRP78, p-PERK, NF-κB, MCP-1, and VEGF. THP-1 migration was markedly higher than C.S over the indicated time. These alterations were inhibited by the administration of 4-PBA.

Significance

These findings suggest that regulation of ER stress coupled with inflammatory activation by 4-PBA would be a promising therapy to reverse the process and development of uremic serum-induced EC dysfunction.     

Single nucleotide polymorphisms in the mitochondrial control region are associated with metabolic phenotypes and oxidative stress

Objective

To identify the mitochondrial DNA (mtDNA) single nucleotide polymorphisms (SNPs) in the control region and elucidate their role in metabolic phenotypes and oxidative stress.

Methods

A total of 861 nondiabetic subjects were enrolled, including 250 impaired fasting glucose (IFG) and 370 obese subjects (body mass index [BMI] > 25 kg/m²). Antioxidant status presented as total free thiol level was determined from serum samples. DNA was extracted from peripheral blood leucocytes, and the sequences were analyzed using the DNASTAR software. SNPs were identified by comparison with the Cambridge Reference Sequence.

Results

After adjusting odds ratios for age, sex, and BMI, the selected independently significant SNPs indicated 4 susceptible SNPs: SNP-16126C and SNP-16261T, which were related to abdominal obesity (P = 0.009; 0.06); SNP-16390A, related to hypertension (HTN) (P = 0.007); and SNP-16092C, related to decreased antioxidant capacity (P = 0.015). In the obese subgroup, 3 susceptible SNPs included SNP-16189C and SNP-16260T, which showed significantly higher IFG prevalence (P = 0.016 and 0.024, respectively), and SNP-16519C, which was significantly higher in the HTN group (P = 0.036). As to protective SNPs, 5 protective SNPs were identified in all subjects but only one SNP-16093C is consistent in obese group, which showed a significantly lower prevalence in patients with abdominal obesity and was associated with a higher antioxidant status (P < 0.001).

Conclusion

SNPs in the mtDNA control region are associated with metabolic phenotypes and oxidative stress markers. Some SNPs are relating to the interaction between obesity and genetic factors. The beneficial effects of these protective SNPs were insignificant and some susceptible SNPs became dominant within the obese subgroup. Subjects harboring these SNPs should avoid excessive weight gain.     

Meta-analysis on association between the ATP-binding cassette transporter A1 gene (ABCA1) and Alzheimer's disease

Purpose

In the past decade, a number of case–control studies have been carried out to investigate the relationship between ABCA1 polymorphisms and Alzheimer's disease (AD). However, these studies have yielded contradictory results. To investigate this inconsistency, a meta-analysis was performed.

Methods

Databases including PubMed, Web of Science, EMBASE and CNKI were searched to find relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association.

Results

A total of 13 case–control studies, involving 6214 patients and 6034 controls for ABCA1 polymorphisms were included. In a combined analysis, the summary per-allele odds ratio for AD of the 219 K was 1.03 (95% CI: 0.93–1.14, p = 0.56). A meta-analysis of studies on the 883 M and 1587 K variant showed no significant overall association with AD, yielding a per-allele odds ratio of 1.10 (95% CI: 0.96–1.26, p = 0.16), and 1.09 (95% CI: 0.97–1.24, p = 0.16) respectively. Similar results were also found for heterozygous and homozygous. In the subgroup analysis by ethnicity, sample size, APOE status and onset type, no significant associations were found in almost all genetic models.

Conclusions

In summary, there was no significant association detected between ABCA1 R219K, I883M and R1587K polymorphisms and risk for AD.     

Association of RAGE gene polymorphism with circulating AGEs level and paraoxonase activity in relation to macro-vascular complications in Indian type 2 diabetes mellitus patients

Background and aims

Sustained interaction of advanced glycation end products (AGEs) with their receptor RAGE and subsequent signaling plays an important role in the development of diabetic complications. Genetic variation of RAGE gene may be associated with the development of vascular complications in type 2 diabetes mellitus (T2DM).

Objectives

The present study aimed to explore the possible association of RAGE gene polymorphisms namely − 374T/A, − 429T/C and G82S with serum level of AGEs, paraoxonase (PON1) activity and macro-vascular complications (MVC) in Indian type 2 diabetes mellitus patients (T2DM).

Methods

A total of 265 diabetic patients, including DM without any complications (n = 135), DM-MVC (n = 130) and 171 healthy individuals were enrolled. Genotyping of RAGE variants were assessed by polymerase chain reaction-restriction fragment length polymorphism. Serum AGEs were estimated by ELISA and fluorometrically. and PON1 activity was assessed spectrophotometrically.

Results

Of the three examined SNPs, association of − 429T/C polymorphism with MVC in T2DM was observed (OR = 3.001, p = 0.001) in the dominant model. Allele ‘A’ of − 374T/A polymorphism seems to confer better cardiac outcome in T2DM. Patients carrying C allele (− 429T/C) and S allele (G82S) had significantly higher AGEs levels. − 429T/C polymorphism was also found to be associated with low PON1 activity. Interaction analysis revealed that the risk of development of MVC was higher in T2DM patients carrying both a CC genotype of − 429T/C polymorphism and a higher level of AGEs (OR = 1.343, p = 0.040).

Conclusion

RAGE gene polymorphism has a significant effect on AGEs level and PON1 activity in diabetic subjects compared to healthy individuals. Diabetic patients with a CC genotype of − 429T/C are prone to develop MVC, more so if AGEs levels are high and PON1 activity is low.     

Propylisopropylacetic acid (PIA), a constitutional isomer of valproic acid,uncompetitively inhibits arachidonic acid acylation by rat acyl-CoA synthetase 4: A potential drug for bipolar disorder

Background

Mood stabilizers used for treating bipolar disorder (BD) selectively downregulate arachidonic acid (AA) turnover (deacylation–reacylation) in brain phospholipids, when given chronically to rats. In vitro studies suggest that one of these, valproic acid (VPA), which is teratogenic, reduces AA turnover by inhibiting the brain long-chain acyl-CoA synthetase (Acsl)4 mediated acylation of AA to AA-CoA. We tested whether non-teratogenic VPA analogues might also inhibit Acsl4 catalyzed acylation, and thus have a potential anti-BD action.

Methods

Rat Acsl4-flag protein was expressed in Escherichia coli, and the ability of three VPA analogues, propylisopropylacetic acid (PIA), propylisopropylacetamide (PID) and N-methyl-2,2,3,3-tetramethylcyclopropanecarboxamide (MTMCD), and of sodium butyrate, to inhibit conversion of AA to AA-CoA by Acsl4 was quantified using Michaelis–Menten kinetics.

Results

Acsl4-mediated conversion of AA to AA-CoA in vitro was inhibited uncompetitively by PIA, with a K_i of 11.4 mM compared to a published K_i of 25 mM for VPA, while PID, MTMCD and sodium butyrate had no inhibitory effect.

Conclusions

PIA's ability to inhibit conversion of AA to AA-CoA by Acsl4 in vitro suggests that, like VPA, PIA may reduce AA turnover in brain phospholipids in unanesthetized rats, and if so, may be effective as a non-teratogenic mood stabilizer in BD patients.