Functional improvements in ß-lactoglobulin by conjugating with soybean soluble polysaccharide.

Soybean soluble polysaccharide (SSPS) was hydrolyzed by autoclaving for 6 and 12 h to obtain SSPS (6 h) and SSPS (12 h). Bovine ß-lactoglobulin (BLG) was conjugated with each SSPS by the Maillard reaction to improve its function. Conjugation between BLG and each SSPS was confirmed by Sodium dodecyl sulfate polyacrylamide gel electrophoresis and isoelectric focusing. BLG-SSPS (6 h) and BLG-SSPS (12 h), respectively, retained approximately 56 and 43% of the retinol-binding activity of BLG. Structural analyses by intrinsic fluorescence and enzyme-linked immunosorbent assay with monoclonal antibodies indicated that the native structure of BLG had almost been maintained in each conjugate and that the surface structure was covered by conjugated SSPS. The emulsifying properties of BLG were improved in each conjugate at pH 3, 5, and 7 in the presence of 0.2 M NaCl. The antibody responses to BLG-SSPS (6 h) and BLG-SSPS (12 h) were considerably reduced in BALB/c mice. We conclude that conjugation with SSPS was very effective for improving the function of BLG and this study would contribute to greater utilization of SSPS.

Validation of a new protocol for a zebrafish MEFL (malformation or embryo-fetal lethality) test method that conforms to the ICH S5 (R3) guideline.

Detecting the toxic effects of chemicals on reproduction and development without using mammalian animal models is crucial in the exploitation of pharmaceuticals for human use. Zebrafish are a promising animal model for investigating pharmacological effects and toxicity during vertebrate development. Several studies have suggested the use of zebrafish embryos for the assessment of malformations or embryo-fetal lethality (MEFL). However, a reproducible protocol as a standard for the zebrafish MEFL test method that fulfills global requests has not been established based on the International Council of Harmonisation (ICH) S5 (R3) guidelines. To establish such a toxicity test method, we developed a new and easy protocol to detect MEFL caused by chemicals, especially those with teratogenic potential, using fertilized zebrafish eggs (embryos) within 5 days of development. Our toxicity test trials using the same protocol in two to four different laboratories corroborated the high inter-laboratory reproducibility. Our test method enabled the detection of 18 out of 22 test compounds that induced rat MEFL. Thus, the prediction rate of our zebrafish test method for MEFL was almost 82% compared with that of rat MEFL. Collectively, our study proposes the establishment of an easy and reproducible protocol for the zebrafish MEFL test method for reproductive and developmental toxicity that meets ICH guideline S5 (R3), which can be further considered in combination with information from other sources for regulatory use.

Lysophosphatidic acid receptor-3 increases tumorigenicity and aggressiveness of rat hepatoma RH7777 cells.

Lysophosphatidic acid (LPA), which interacts with G protein-coupled transmembrane LPA receptors exhibits several biological effects, such as cell proliferation, migration, and differentiation. Recently, it has been reported that alteration of LPA receptor genes occurs in several cancer cells. In this study, to assess the biological role of LPA receptor-3 (LPA3 ) in the pathogenesis of tumor cells, we generated the Lpar3-expressing cells (RHa3B12 and RHa3G8) from rat hepatoma RH7777 cells, and examined their abilities of cell migration and tumorigenicity, compared with the Lpar3-unexpressing cells. In cell motility and invasion assays, RHa3B12 and RHa3G8 cells showed significantly higher intrinsic activity without LPA treatment than control RH7777AB cells. LPA treatment further increased cell motility and invasion of these cells. The cell motility of RHa3B12 and RHa3G8 cells stimulated by LPA treatment was significantly suppressed by pretreatment with inhibitors of Gi or Gq proteins. In a soft agar assay, the large sized colonies were formed in RHa3B12 and RHa3G8 cells, but not in RH7777AB cells. The cell survival of RHa3G8 cells treated with cisplatin (CDDP) or doxorubicin (DOX) was higher than that of RH7777AB cells, correlating with the elevated expression levels of multidrug-resistance related genes, Mdr1a, Mdr1b, and Gstp1. These results suggest that LPA3 may be involved in progression and aggressiveness of rat hepatoma RH7777 cells.

Tobacco smoke-induced skin pigmentation is mediated by the aryl hydrocarbon receptor.

It is widely recognized that tobacco smoke causes skin pigmentation. No studies, however, have directly evaluated the mechanisms of the changes in smoker's skin pigmentation. In this study, when cultured with water-soluble tobacco smoke extract, the human epidermal melanocytes grew to a large size and produced more melanins. We evaluated melanocyte activation by quantifying microphthalmia-associated transcription factor (MITF) expression by real-time polymerase chain reaction. MITF expression was significantly and dose-dependently increased by exposure to tobacco smoke extract. The Wnt/ß-catenin signalling pathway seemed to mediate the tobacco smoke extract-induced melanocyte activation. Immunocytochemical studies revealed that the activated melanocytes actively expressed aryl hydrocarbon receptors (AhR) around the nuclear membrane. The tobacco smoke extract-induced MITF activation was inhibited by RNA silencing of the AhR. This study provides the evidence that tobacco smoke enhances pigmentation in vitro and that the increase in pigmentation may involve ß-catenin- and AhR-mediated mechanisms inside human melanocytes.

Effects of Pesticide Intake on Gut Microbiota and Metabolites in Healthy Adults.

Animal experiments have indicated that pesticides may affect gut microbiota, which is responsible for the production of short-chain fatty acids (SCFAs) and polyamines. Here, we present a preliminary observation of the relationship between pesticide exposure and fecal SCFAs and polyamines in Japanese adults. In total, 38 healthy adults aged 69 ± 10 years (mean ± SD) were recruited and subjected to stool and spot urine tests. Urinary dialkylphosphates (DAP), 3-phenoxybenzoic acid, and glyphosate were assayed as pesticide exposure markers of organophosphorus insecticide (OP), a pyrethroid insecticide, and glyphosate, respectively. Significant negative correlations (p < 0.05, Spearman's rank correlation coefficient) were found between urinary DAP, fecal acetate (r = −0.345), and lactate (r = −0.391). Multiple regression analyses revealed that urinary DAP was a significant explanatory variable of fecal acetate concentration (p < 0.001, ß = −24.0, SE = 4.9, t = −4.9) with some vegetable intake (adjusted R-square = 0.751). These findings suggest that OP exposure is independently associated with lower fecal acetate levels, which may contribute to human health in middle-aged and older adult groups. Given that the human gut environment has long-term effects on the host, studies on wide-range age groups, including children, are necessary.

Improvement in both severe obsessive-compulsive disorder and refractory tardive dystonia following electroconvulsive therapy: A case report.

Background: Obsessive-compulsive disorder (OCD) is often resistant to treatment and may be complicated by tardive dystonia (TDt) with the use of neuroleptics. Furthermore, patients with TDt often have an inadequate response to pharmacotherapy. Although electroconvulsive therapy (ECT) is considered a common treatment option for both TDt and OCD, its efficacy has not been well established for either condition. Case Presentation: Our case was a 37-year-old Japanese woman who showed improvement in both refractory TDt and severe OCD following ECT. A total of 12 ECT sessions resulted in an improvement in both diseases. To the best of our knowledge, this is the first report of a case in which ECT was effective for both TDt and OCD. Conclusion: Our report highlights the following two points: when TDt is associated with severe OCD, and the effect of pharmacotherapy is inadequate, ECT may be considered as a treatment option; given the common mechanism of frontal cortex-basal dysfunction reported in both dystonia and OCD, ECT may have an effect on this pathway.

Loss of lysophosphatidic acid receptor-3 enhances cell migration in rat lung tumor cells.

Lysophosphatidic acid (LPA) indicates several biological effects, such as cell proliferation, differentiation and migration. LPA interacts with G protein-coupled transmembrane LPA receptors. In our previous report, we detected that loss of the LPA receptor-1 (Lpar1) expression is due to its aberrant DNA methylation in rat tumor cell lines. In this study, to assess an involvement of the other LPA receptor, Lpar3, in the pathogenesis of rat lung tumor cells, we measured the expression levels of the Lpar3 gene and its DNA methylation status by reverse transcription (RT)-polymerase chain reaction (PCR) and bisulfite sequencing analyses, respectively. RLCNR lung adenocarcinoma cells showed reduced expression of the Lpar3, compared with normal lung tissues. In the 5' upstream region of the Lpar3, normal lung tissues were unmethylated. By contrast, RLCNR cells were highly methylated, correlating with reduced expressions of the Lpar3. Based on these results, we generated the Lpar3-expressing RLCNR-a3 cells and measured the cell migration ability. Interestingly, the cell migration of RLCNR-a3 cells was significantly lower than that of RLCNR cells. This study suggests that loss of the Lpar3 due to aberrant DNA methylation may be involved in the progression of rat lung tumor cells.

Possible involvement of lysophosphatidic acid receptor-5 gene in the acquisition of growth advantage of rat tumor cells.

Aberrant expressions of lysophosphatidic acid (LPA) receptor genes have been reported in tumor cells. Here, we measured the expression levels of the Lpa5 gene and its DNA methylation status in rat tumor cells, and investigated cell growth effects of LPA in Lpa5 expressed cells. Real-time reverse transcription (RT)-polymerase chain reaction (PCR) analysis revealed that increased expressions of the Lpa5 gene were detected in rat liver-derived hepatoma RH7777 and lung-derived adenocarcinoma RLCNR cells. For the analysis of methylation status, bisulfite sequencing was performed with RH7777 and RLCNR cells and compared with other tumor cells and liver epithelial cells. The Lpa5 gene in Lpa5 unexpressed cells and liver epithelial cells were highly methylated in the 5' upstream region. In contrast, the Lpa5 gene in RH7777 and RLCNR cells was unmethylated, correlating with increased expressions of Lpa5. In the assays for cell growth effects of LPA, LPA enhanced cell proliferation and motility in RH7777 and RLCNR cells. LPA also stimulated cell invasion in RLCNR, but not in RH7777 cells. In rat liver and lung tumors induced by nitroso-compounds, 4 out of 6 hepatocellular carcinomas and 5 out of 6 lung adenocarcinomas indicated increased expressions of Lpa5 with unmethylated status. These results suggest that increased Lpa5 expressions due to aberrant DNA methylation may be involved in the acquisition of growth advantage of rat tumor cells.

Distinct DNA methylation patterns of lysophosphatidic acid receptor genes during rat hepatocarcinogenesis induced by a choline-deficient L-amino acid-defined diet.

Altered expressions of lysophosphatidic acid (LPA) receptor genes have been reported in tumor cells of human and rats. Recently, we detected the frequent mutations of LPA receptor-1 (LPA1) gene in rat hepatocellular carcinomas (HCCs) induced by a choline-deficient L-amino acid-defined (CDAA) diet. In this study, the DNA methylation patterns of LPA receptor genes and their expression levels during rat hepatocarcinogenesis induced by the CDAA diet were investigated. Six-week-old F344 male rats were continuously fed with the CDAA diet, and animals were then killed at 7 days and 2, 12, 20, and 75 weeks, respectively. Genomic DNAs were extracted from livers and HCCs for the assessment of methylation status by bisulfite sequencing, comparing to normal livers. The livers of rats fed the CDAA diet were unmethylated in LPA1 and LPA2 genes as well as normal livers. In LPA3 gene, although normal livers were unmethylated, the livers at 7 days and 2 and 12 weeks weakly or moderately methylated and those at 20 weeks markedly methylated. Moreover, 4 HCCs were completely methylated in LPA3 gene. Expression levels of LPA receptor genes in the livers of rats fed the CDAA diet and HCCs were correlating with DNA methylation status. These results indicate that DNA methylation status of the LPA3 gene was disturbed in the livers of rats fed the CDAA diet and established HCCs, suggesting that alterations of the LPA receptor genes might be involved during rat hepatocarcinogenesis induced by the CDAA diet.

Different expressions and DNA methylation patterns of lysophosphatidic acid receptor genes in mouse tumor cells.

OBJECTIVE: Lysophosphatidic acid (LPA) receptors act as several biological effectors through LPA, which is a bioactive phospholipid. Recently, aberrant expressions of LPA receptor genes due to DNA methylation have been detected in several tumor cells. In this study, we measured expression levels and DNA methylation status of LPA receptor genes in mouse tumor cells, LL/2 lung carcinoma, B16F0 melanoma, FM3A mammary carcinoma and L1210 leukemia cells, compared with normal tissues. METHODS: Total RNAs were extracted and RT-PCR analysis was performed. For DNA methylation status, bisulfite sequencing analysis was carried out, comparing outcomes with other tumor cells and normal tissues. RESULTS: The expressions of LPA1 gene were shown in LL/2, but not in B16F0, FM3A and L1210 cells. While the LPA2 gene was expressed in all 4 tumor cells, the LPA3 gene was unexpressed in them. The LPA1 and LPA3 unexpressed cells were highly methylated, although normal tissues were all unmethylated. The DNA methylation status was correlated with gene expression levels in cancer cells. CONCLUSION: The present results demonstrate that DNA methylation patterns of LPA receptor genes are dependent on cancer cell types, suggesting that LPA receptors may be new molecular targets for therapeutic approaches and chemoprevention.

Mutations of lysophosphatidic acid receptor genes in human osteosarcoma cells.

OBJECTIVE: Lysophosphatidic acid (LPA), which is a bioactive phospholipid, interacts with specific G protein-coupled transmembrane receptors. Recently, alterations in LPA receptor genes have been reported in some tumor cells. In this study, to assess an involvement of LPA receptor genes in the development of human cancer cells, we looked for the presence of mutations in LPA receptor 1-6 (LPA1-6) genes in MG63 osteosarcoma, HT1080 fibrosarcoma, A549 lung adenocarcinoma, MCF-7 breast carcinoma, and G-361 melanoma cells. METHODS: Genomic DNAs were extracted from each cell and polymerase chain reaction-single-strand conformation polymorphism analysis was performed to identify the mutations. RESULTS: MG63 showed mutations in LPA1 and LPA3 genes, while no mutations in the LPA receptor genes were found in HT1080, A549, MCF-7 and G-361 cells. Sequence analysis revealed a CGC to CGT (Arg to Arg) transition at codon 314 in LPA1, and a GCG to GTG (Ala to Val) transition at codon 247 in LPA3. CONCLUSION: These results indicated that the mutations in LPA1 and LPA3 genes occur in MG63 cells, suggesting that the alterations in LPA receptor genes may play some role in the pathogenesis in human osteosarcoma cells.

Differential function of lysophosphatidic acid receptors in cell proliferation and migration of neuroblastoma cells.

Lysophosphatidic acid (LPA) is a bioactive lipid mediator that induces diverse cellular biological effects and interacts with G protein-coupled transmembrane LPA receptors. In the present study, to assess biological roles of LPA receptors in the pathogenesis of tumor cells, each LPA receptor (Lpar1, Lpar2 or Lpar3)-expressing rat neuroblastoma B103 cells (lpa1-1, lpa2-2 or lpa3-3-2 cells, respectively) were used. In cell motility and invasion assay, lpa2-2 and lpa3-3-2 cells showed significant higher intrinsic activity without LPA treatment than LPA receptor-unexpressing AB2-1bf cells. LPA treatment further increased cell motility of these cells, which was suppressed by the pretreatment with inhibitors of Gi, Gq protein, or ROCK. By contrast, lpa1-1 cells markedly decreased intrinsic cell motility and invasion, compared with AB2-1bf cells. Constitutively active mutant Lpar1-expressing cells (lpa1Δ-1) showed significant high motility, comparable with those of lpa2-2 and lpa3-3-2. In soft agar assay, lpa3-3-2 and lpa1Δ-1 cells showed colony formation, but other cells failed. These results suggest that LPA receptors may play different roles in cell proliferation and migration of rat neuroblastoma cells.

Mutations and aberrant transcriptions of Stk11 (Lkb1) gene in rat liver tumors.

UNLABELLED: To clarify the involvement of the Stk11/Lkb1 gene in the development of hepatocellular carcinomas (HCCs), its alteration in rat HCCs induced by exogenous and endogenous liver carcinogenesis models was investigated. MATERIALS AND METHODS: Fifteen HCCs induced by N-nitrosodiethylamine (DEN) and 12 HCCs induced by a choline-deficient L-amino acid-defined (CDAA) diet were obtained. To assess mutations and aberrant transcriptions of the Stk11 gene, polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) and reverse transcription (RT)-PCR analyses were performed, respectively. RESULTS: A mutation was detected in only 1 out of 15 HCCs by DEN, but no mutations in 12 HCCs by the CDAA diet. Aberrant transcripts were found in 4 out of 15 HCCs by DEN and in 3 out of 12 HCCs by the CDAA diet. CONCLUSION: These results suggest that alterations of the Stk11 gene may play a limited role in both exogenous and endogenous rat liver carcinogenesis.