Effect of 5-HT1A gene polymorphisms on antidepressant response in major depressive disorder

Variability in antidepressant response is due to genetic and environmental factors. Among genetic factors, the ones controlling for availability of the drug at the target site are interesting candidates. Rs6295C/G SNP in the 5-HT1A gene (HTR1A) has been found to affect the expression and function of HTR1A. In fact rs6295C/G is in strong linkage disequilibrium with other polymorphisms of HTR1A suggesting that those functional effects could be associated with polymorphisms other than or together with the synonymous rs6295C/G. In the present study we examined the possible association of a panel of markers in strong linkage disequilibrium of the HTR1A with SSRI/SNRI response in 137 Japanese major depression subjects followed for 6 weeks. We observed a significant association of better response to antidepressant in rs10042486C/C (P < 0.0001), rs6295G/G (P < 0.0001) and rs1364043T/T (P = 0.018) genotype carriers (minor allele homozygotes), independently from clinical variables. Furthermore minor allele homozygous carriers in all these three SNPs were associated with treatment response by various assessment such as HAM-D score change over time (P = 0.001), week 2 (P < 0.0001), 4 (P = 0.007), and 6 (P = 0.048) as well as response rate (P = 0.0005) and remission rate (P = 0.004). We also pointed out the genotyping mis-definition of rs6295C/G in the previous four articles. In conclusion, this is the first study that reports a significant association of antidepressant response with rs10042486C/T and rs1364043T/G variants of HTR1A and also with rs10042486-rs6295-rs1364043 combination. This finding adds an important information for the pathway of detecting the genetics of antidepressant response even if results must be verified on larger samples.

Beneficial effect of taurine treatment against doxorubicin-induced cardiotoxicity in mice

Though the administration of taurine is clinically efficacious against heart failure, the mechanism underlying its cardioprotection remains to be established. To provide information on the mechanism, we examined the effects of taurine on doxorubicin (DOX)-induced cardiotoxicity, with an emphasis on ROS generation and cardiac gene inhibition. Oral administration of taurine (3% w/v in tap water) dramatically reduced the mortality rate in both the acute or sub-acute toxic models of DOX toxicity. It was shown that taurine prevented DOX-induced oxidative stress as determined from cardiac glutathione content. Interestingly, Northern blot analysis revealed that DOX altered cardiac gene expression, including that of alpha-myosin heavy chain, ventricular myosin light chain-2 isoform and brain natriuretic peptide, an effect partially ameliorated by taurine treatment. In conclusion, taurine suppresses ROS generation and regulates gene expression in the DOX treated heart.

Involvement of transcriptional factor TonEBP in the regulation of the taurine transporter in the cardiomyocyte

Taurine is found in high concentrations in heart where it exerts several actions that could potentially benefit the diseased heart. The taurine transporter (TauT) is crucial for the maintenance of high taurine levels in the heart. Although cardiac taurine content is altered in various pathological conditions, little is known about the regulatory mechanisms governing TauT expression in cardiac myocytes. In the present study, we found that treatment with the antineoplastic drug doxorubicin (DOX), which is also known as a cardiotoxic agent, decreases the expression of the TauT gene in cultured cardiomyocytes isolated from the neonatal rat heart. Based on data obtained using a luciferase assay, DOX significantly reduced transcriptional activity driven by the TauT promoter, while deletion or mutation of a tonicity-response element (TonE) in this promoter eliminated the change of promoter activity. The protein level of the TonE-binding protein (TonEBP) was reduced by DOX treatment. In addition, the reduction in TonEBP protein content was suppressed by proteasome inhibitors. In conclusion, the DOX-enhanced degradation of TonEBP resulting in reduced TauT expression in the cardiomyocyte.

Microwave heating of tea residue yields polysaccharides, polyphenols, and plant biopolyester

Microwave heating was used to produce aqueous-soluble components from green, oolong, and black tea residues. Heating at 200-230 degrees C for 2 min extracted 40-50% of polysaccharides and 60-70% of the polyphenols. Solubilization of arabinose and galactose by autohydrolysis occurred with heating above 170 degrees C, whereas heating above 200 degrees C was necessary to solubilize xylose. Catechins were soluble in water by heating at low temperature (110 degrees C); however, new polyphenols having strong antioxidant activity were produced above 200 degrees C. The amount of solubilized materials and antioxidant activity increased with increased fermentation of harvested tea leaves (green tea < oolong tea < black tea). Cutin, a plant biopolyester, remained in the residue after heating as did cellulose and lignin/tannin. The predominant cutin monomer that was recovered was 9,10-epoxy-18-hydroxyoctadecanoic acid, followed by dihydroxyhexadecanoic acid and 9,10,18-trihydroxyoctadecanoic acid.

Study of active controlled tocilizumab monotherapy for rheumatoid arthritis patients with an inadequate response to methotrexate (SATORI): significant reduction in disease activity and serum vascular endothelial growth factor by IL-6 receptor inhibition therapy

We investigated the clinical efficacy and safety of tocilizumab (a humanized anti-IL-6 receptor antibody) monotherapy in active rheumatoid arthritis (RA) patients with an inadequate response to low dose methotrexate (MTX). In a multicenter, double-blind, randomized, controlled trial, 125 patients were allocated to receive either tocilizumab 8 mg/kg every 4 weeks plus MTX placebo (tocilizumab group) or tocilizumab placebo plus MTX 8 mg/week (control group) for 24 weeks. The clinical responses were measured using the American College of Rheumatology (ACR) criteria and the Disease Activity Score in 28 joints. Serum vascular endothelial growth factor (VEGF) levels were also monitored. At week 24, 25.0% in the control group and 80.3% in the tocilizumab group achieved ACR20 response. The tocilizumab group showed superior ACR response criteria over control at all time points. Additionally, serum VEGF levels were significantly decreased by tocilizumab treatment. The overall incidences of adverse events (AEs) were 72 and 92% (serious AEs: 4.7 and 6.6%; serious infections: 1.6 and 3.3%) in the control and the tocilizumab groups, respectively. All serious adverse events improved by adequate treatment. Tocilizumab monotherapy was well tolerated and provided an excellent clinical benefit in active RA patients with an inadequate response to low dose MTX.

[A case of bleeding tendency due to warfarin in a patient treated with chemotherapy by S-1]

A 82-year-old male patient had suffered from a cancer of the papilla of Vater. After the operation, he received 4 courses of gemcitabine(GEM)adjuvant chemotherapy and warfarin(WF)administration because of thrombosis in the left internal jugular vein. Since the tumors re-grew, GEM was discontinued, and chemotherapy including S-1 and GEM was examined. However, the chemotherapy could not be continued because of edema in both lower legs and tassel midway in the 2nd course. Because of a bleeding tendency(non-measurable INR(international normalized ratio of prothrombin time)), WF administration was discontinued on the 11th day after S-1/GEM combined therapy was suspended. On the following day, although the INR value recovered to 1.7, it gradually worsened and the symptoms of pulmonary embolism developed on the 13th day. Then, INR was controlled by continuous infusion of heparin. Since the INR level decreased after that, in addition to heparin, re-medication of WF was performed. We tried to analyze the genotype of a patient, who had a tendency to bleed by coadministration of WF with S-1, in terms of hepatic cytochrome P-450(CYP)2C9 and vitamin K epoxide reductase complex subunit 1(VKORC1). We also measured the plasma concentration of S-and R-WF by HPLC after obtaining informed consent from the patient. We found that he is homozygous for CYP2C9 1/1 and for A/A of VKORC1(-1639G>A). The obtained data did not show the abnormalities of blood coagulation. Because the genotype of a patient with a tendency to bleed was a major type in a Japanese population, fine monitoring of INR is required in order to prevent side effects of blood coagulation by S-1 and WF coadministration, regardless of patient genotypes.

No association of TPH1 218A/C polymorphism with treatment response and intolerance to SSRIs in Japanese patients with major depression

BACKGROUND

Variability in antidepressant response is due to genetic and environmental factors. Since SSRIs exert their activity enhancing the serotonin turnover, genes coding for proteins of the serotonin system are key candidates for a possible genetic influence with response to SSRIs. Therefore tryptophan hydroxylase (TPH), the rate-limiting enzyme in the biosynthesis of serotonin in the raphe nuclei could be a candidate. In the present study, we examined the possible association of the TPH1 218A/C polymorphism with response to SSRIs in a sample of Japanese patients with major depression.

METHODS

The 21-item Hamilton Rating Scale for Depression (HAM-D) was administered to evaluate depressive symptoms at baseline and bi-weekly over 6 weeks of treatment. All patients were genotyped for the TPH1 218A/C polymorphism.

RESULTS

Repeated-measures analysis of variance of HAM-D score change over time with baseline scores and 5-HTTLPR variants included in the model as covariate showed no significant association of this SNP with treatment response to SSRIs. Furthermore, no significant association of this SNP could be observed with both responder rate at weeks 2, 4 and 6 and intolerance to SSRIs.

CONCLUSION

The result suggests that 218A/C variants of TPH1 cannot play a major role as predictor of treatment response as well as intolerance in Japanese patients with major depression.

Antidepressant response and intolerance to SSRI is not influenced by G-protein beta3 subunit gene C825T polymorphism in Japanese major depressive patients

The G-protein beta3 subunit (GNB3) gene is a key modulator of signal transduction and is a major candidate for SSRIs response. The aim of the present study is to test a possible effect of the C825T polymorphism on the antidepressant response and intolerance to selective serotonin reuptake inhibitors (SSRIs) in 146 Japanese samples with major depression treated with paroxetine or fluvoxamine for 6 weeks. The severity of depression symptom was assessed using the 21-item Hamilton Rating Scale for Depression (HAM-D) and adverse drug reactions were evaluated bi-weekly. No association with SSRIs treatment response was observed in 107 completers also including HAM-D baseline scores, SSRI type or/and 5-HTTLPR variants in the model as covariates. Furthermore, no significant association could be observed with intolerance to SSRIs in the whole subjects. The result suggests that C825T variants of GNB3 cannot play a major role as a predictor of treatment response as well as intolerance to SSRIs in Japanese patients with major depression.

Connective tissue growth factor induces cardiac hypertrophy through Akt signaling

In the process of cardiac remodeling, connective tissue growth factor (CTGF/CCN2) is secreted from cardiac myocytes. Though CTGF is well known to promote fibroblast proliferation, its pathophysiological effects in cardiac myocytes remain to be elucidated. In this study, we examined the biological effects of CTGF in rat neonatal cardiomyocytes. Cardiac myocytes stimulated with full length CTGF and its C-terminal region peptide showed the increase in cell surface area. Similar to hypertrophic ligands for G-protein coupled receptors, such as endothelin-1, CTGF activated amino acid uptake; however, CTGF-induced hypertrophy is not associated with the increased expression of skeletal actin or BNP, analyzed by Northern-blotting. CTGF treatment activated ERK1/2, p38 MAPK, JNK and Akt. The inhibition of Akt by transducing dominant-negative Akt abrogated CTGF-mediated increase in cell size, while the inhibition of MAP kinases did not affect the cardiac hypertrophy. These findings indicate that CTGF is a novel hypertrophic factor in cardiac myocytes.

Atrogin-1 ubiquitin ligase is upregulated by doxorubicin via p38-MAP kinase in cardiac myocytes

AIMS

Doxorubicin (DOX) is one of the most effective anti-neoplastic agents; however, its clinical use is limited by drug-induced cardiomyopathy. The molecular mechanisms responsible for this toxicity remain to be fully addressed. In the present study, we investigated the involvement of atrogin-1, one of the muscle-specific ubiquitin ligases, in DOX-induced cardiotoxicity.

METHODS AND RESULTS

This method involved intraperitoneal administration of DOX-induced atrogin-1 in the hearts and skeletal muscles of C57BL/6 mice. Consistently, atrogin-1 mRNA was upregulated with DOX treatment in cultured rat neonatal cardiomyocytes. Adenoviral transfer of atrogin-1 induced a reduction in cell size that was ameliorated by the ubiquitin proteasome inhibitor, MG-132. The transduction of constitutively active Akt (caAkt), a serine/threonine protein kinase, inhibited the DOX-mediated induction of atrogin-1. The phosphorylation status of Akt and its downstream target, FOXO, was not affected by DOX. DOX treatment did not activate the atrogin-1 promoter that contains FOXO-binding sites, suggesting that DOX induced atrogin-1 without modulating the Akt/FOXO pathway; importantly, DOX activated p38-mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK). Furthermore, pharmacological inhibition of p38-MAPK, but not JNK, abrogated DOX-mediated induction of atrogin-1. Finally, adenoviral transfer of caAkt inhibited the DOX-induced p38-MAPK activation.

CONCLUSIONS

DOX induces atrogin-1 through a p38-MAPK-dependent pathway in cardiac myocytes. Constitutive activation of Akt negatively regulates DOX-mediated atrogin-1 induction by inhibiting p38-MAPK activity as a novel mechanism.

Adrenergic beta1 receptor polymorphism (Ser49Gly) is associated with obesity in type II diabetic patients

In the process of lipolysis, adipocytes are stimulated by catecholamines through beta(1), beta(2), and beta(3) adrenergic receptors (ARs). So far, beta(2) and beta(3) AR polymorphisms have been reported related to obesity. However, the relation of beta(1)AR polymorphisms to obesity has not been evaluated. In the present study, we examined whether betaAR polymorphisms are associated with obesity-related phenotype in type II diabetic patients. Polymorphisms of beta(1)Ser49Gly, beta(1)Arg389Gly, beta(2)Arg16Gly, beta(2)Gln27Glu and beta(3)Trp64Arg were genotyped in 188 type II diabetic patients by PCR-RFLP. Among these polymorphisms, beta(1)Ser49Gly was found to be associated with obesity. Subjects with beta(1)Gly49 allele showed higher body mass index (BMI) than those with Ser49/Ser49 genotype (24.7+/-3.7 vs. 23.4+/-3.3 kg/m(2); p=0.031). Subjects with beta(1)Gly49 allele were more frequently overweight (BMI >or= 25 kg/m(2)) compared with beta(1)Ser49 homozygous group (42.1 vs. 24.4%, p=0.015). By multiple linear regression analysis, beta(1)Ser49Gly polymorphism was independently associated with higher BMI (p=0.019, beta=0.166). Our data indicate that the Gly49 allele in beta(1)AR is associated with higher BMI in type II diabetic patients. Genotyping for beta(1)Ser49Gly polymorphism in type II diabetic patients may have clinical benefit to predict obesity, thereby contributing to the prevention of insulin resistance.

MTHFR gene polymorphism is susceptible to diabetic retinopathy but not to diabetic nephropathy in Japanese type 2 diabetic patients

AIMS

Previously, we have proposed that methylenetetrahydrofolate reductase (MTHFR) gene polymorphism (C677T) could be a risk factor for diabetic retinopathy. To support our suggestion, we examined in detail the association of MTHFR polymorphism with diabetic retinopathy and nephropathy in Japanese type 2 diabetic patients.

METHODS

Subjects (n=190) were free of cardiovascular diseases and were not on hemodialysis. Retinopathy was assessed according to fundamental differentiation; nephropathy was determined according to urinary albumin level; and MTHFR genotype was determined by polymerase chain reaction-restriction fragment length polymorphism. We also analyzed how hyperglycemia affected these three conditions in 131 patients with glycosylated hemoglobin > or =6.5% and fasting blood sugar > or =110 mg/dl.

RESULTS

The frequency of 677T/677T homozygous subjects with retinopathy was higher than the frequencies of the other two genotypes, and a significant difference was observed in the distribution of the genotypes (677C/677C, 41.9%; 677C/677T, 31.1%; 677T/677T, 61.5%; P<.05). The susceptibility of 677T/677T homozygote to retinopathy approached significance [odds ratio (OR)=2.17; 95% confidence interval (95% CI)=0.87-5.42]. However, in the population with hyperglycemia, the 677T/677T homozygote modified the risk for retinopathy (OR=4.30; 95% CI=1.42-13.1), especially the risk for nonproliferative retinopathy. In contrast, the 677T/677T homozygote did not affect the risk for nephropathy (OR=1.17; 95% CI=0.45-3.05), even in subjects with hyperglycemia (OR=1.50; 95% CI=0.50-4.48).

CONCLUSIONS

Our results are highly suggestive of an important role for MTHFR genotype in susceptibility to retinopathy under hyperglycemia, but not to nephropathy. Preventive therapies based on MTHFR polymorphism could delay the onset of retinopathy in type 2 diabetic patients.

ABCB1 (MDR1) gene polymorphisms are associated with the clinical response to paroxetine in patients with major depressive disorder

Variability in antidepressant response is due to genetic and environmental factors. Among genetic factors, the ones controlling for availability of the drug at the target site are interesting candidates. Multidrug resistance 1 (ABCB1, MDR1) gene encodes a blood-brain barrier transporter P-glycoprotein that plays an important role in controlling the passage of substances between the blood and brain. In the present study, we therefore examined the possible association of 3 functional ABCB1 polymorphisms (C3435T: rs1045642, G2677T/A: rs2032582 and C1236T: rs1128503) with response to paroxetine in a Japanese major depression sample followed for 6 weeks. Analysis of covariance at week 6 with baseline scores included in the model as covariate showed significant association of the non-synonymous SNP G2677T/A with treatment response to paroxetine (p=0.011). Furthermore, the wild variants haplotype (3435C-2677G-1236T) resulted associated with poor response (p=0.006). To our best knowledge, this study is the first suggestion of a possible association of ABCB1 variants with SSRIs response.

Dose-escalation study of isoniazid in healthy volunteers with the rapid acetylator genotype of arylamine N-acetyltransferase 2

OBJECTIVE

Genetic polymorphisms of arylamine N-acetyltransferase 2 (NAT2) result in large interindividual differences in the plasma concentration of isoniazid (INH). We hypothesized that the internationally recommended dosage should be increased for patients with two active NAT2 alleles (RA type) in order to achieve appropriate antituberculous efficiency; however, the pharmacokinetic effects of the dose increase have not been fully addressed. To estimate an optimal dosage for RA-type patients, we conducted a dose escalation study in healthy male volunteers carrying NAT2*4/*4.

METHODS

Oral doses of 300 mg, 600 mg, and 900 mg of INH were administered to eight RA-type subjects, whereas 300 mg was administered to eight IA-type subjects with one active allele (NAT2*4). The pharmacokinetic parameters were estimated from plasma INH concentrations for 24 h postdose.

RESULTS

The ratio of the mean area under the plasma-concentration time curve (AUC) was not proportional to the doses (1:2.6:5.0 for 300:600:900-mg dose) in parallel to the plasma concentration at 1 h (C(1)) and 2 h (C(2)) after administration. Compared with the IA-type group given 300 mg, the RA-type group had lower pharmacokinetic parameters at 300 mg (AUC, 66%; C(1), 72%; C(2), 61%), but higher parameters at 600 mg (AUC, 175%; C(1), 196%; C(2), 170%). Plasma concentrations of the IA-type group were within the therapeutic range. An optimal INH dose was calculated as 430 mg (7.2 mg/kg) for RA-type subjects to obtain an AUC comparable with that in IA-type subjects dosed with 300 mg.

CONCLUSION

In RA-type subjects, the pharmacokinetic parameters appeared to lack linearity with the increased dose of INH. We propose that the proper daily dose for RA-type patients is 1.5-times higher than that currently recommended.

Possible inhibitory mechanism of Curcuma drugs on CYP3A4 in 1α,25 dihydroxyvitamin D3 treated Caco-2 cells

Curcuma longa and C. zedoaria, belonging to genus Curcuma, have become prevalent as supplements in East Asia. Curcumin is the most well-studied bioactive component isolated from rhizomes of C. longa and other Curcuma species except C. zedoaria. In this study, we investigated the affects of C. longa, C. zedoaria from Japan and curcumin on CYP3A4. Caco-2 cells, in which CYP3A4 expression was induced by 1alpha,25-(OH)(2)-D(3), were used to mimic the metabolism of small intestine. Caco-2 cells were treated with methanol extracts from two Curcuma rhizomes (0.1mg/ml) or curcumin (30 microM) for 72 h. Both extracts significantly decreased the activity of CYP3A4 by about 85-98%. The 50% inhibitory concentrations of C. longa and C. zedoaria extracts were 0.019 and 0.014 mg/ml, respectively. They caused a 60-70% decrease in CYP3A4 protein. Otherwise, curcumin treatment caused a 30-40% decrease in CYP3A4 catalytic activity and a 38% decrease in CYP3A4 protein expression. Moreover, it was found that both Curcuma extracts and curcumin treatment had no influence on CYP3A4 mRNA expression. Our results suggested that administration of Curcuma drugs might inhibit the catalytic activity of intestinal CYP3A4. However, curcumin was not the major compound responsible for this inhibitory effect.