The Src-Family Kinases SRC and BLK Contribute to the CLDN6-Adhesion Signaling

Cell adhesion molecules, including integrins, cadherins, and claudins (CLDNs), are known to activate Src-family kinases (SFKs) that organize a variety of physiological and pathological processes; however, the underlying molecular basis remains unclear. Here, we identify the SFK members that are coupled with the CLDN6-adhesion signaling. Among SFK subtypes, BLK, FGR, HCK, and SRC were highly expressed in F9 cells and concentrated with CLDN6 along cell borders during epithelial differentiation. Immunoprecipitation assay showed that BLK and SRC, but not FGR or HCK, form a complex with CLDN6 via the C-terminal cytoplasmic domain. We also demonstrated, by pull-down assay, that recombinant BLK and SRC proteins directly bind to the C-terminal cytoplasmic domain of CLDN6 (CLDN6C). Unexpectedly, both recombinant SFK proteins recognized the CLDN6C peptide in a phosphotyrosine-independent manner. Furthermore, by comparing phenotypes of F9:Cldn6:Blk-/- and F9:Cldn6:Src-/- cells with those of wild-type F9 and F9:Cldn6 cells, we revealed that BLK and SRC are essential for CLDN6-triggered cellular events, namely epithelial differentiation and the expression of retinoid acid receptor target genes. These results indicate that selective SFK members appear to participate in the CLDN-adhesion signaling.

REST Inactivation and Coexpression of ASCL1 and POU3F4 Are Necessary for the Complete Transformation of RB1/TP53-Inactivated Lung Adenocarcinoma into Neuroendocrine Carcinoma

Although recent reports have revealed the importance of the inactivation of both RB1 and TP53 in the transformation from lung adenocarcinoma into neuroendocrine carcinoma (NEC), the requirements for complete transformation into NEC have not been elucidated. To investigate alterations in the characteristics associated with the inactivation of RB1/TP53 and define the requirements for transformation into NEC cells, RB1/TP53 double-knockout A549 lung adenocarcinoma cells were established, and additional knockout of REST and transfection of ASCL1 and POU class 3 homeobox transcription factors (TFs) was conducted. More than 60 genes that are abundantly expressed in neural cells and several genes associated with epithelial-to-mesenchymal transition were up-regulated in RB1/TP53 double-knockout A549 cells. Although the expression of chromogranin A and synaptophysin was induced by additional knockout of REST (which mimics the status of most NECs), the expression of another neuroendocrine marker, CD56, and proneural TFs was not induced. However, coexpression of ASCL1 and POU3F4 in RB1/TP53/REST triple-knockout A549 cells induced the expression of not only CD56 but also other proneural TFs (NEUROD1 and insulinoma-associated 1) and induced NEC-like morphology. These findings suggest that the inactivation of RB1 and TP53 induces a state necessary for the transformation of lung adenocarcinoma into NEC and that further inactivation of REST and coexpression of ASCL1 and POU3F4 are the triggers for complete transformation into NEC.

LXRβ Activation Inhibits the Proliferation of Small-cell Lung Cancer Cells by Depleting Cellular Cholesterol

BACKGROUND/AIM

Liver X receptors (LXRs) are nuclear receptors with various functions, including the regulation of cholesterol metabolism, glucose homeostasis, and inflammation. We previously reported that LXR activation inhibits the growth of oral cancer cells by inducing cellular cholesterol efflux and that LXRβ is expressed mainly in small-cell lung cancer (SCLC) tissues. SCLC is one of the most aggressive cancers, and identifying an effective therapeutic target molecule is desirable. Therefore, we investigated whether LXRβ could be an effective target molecule for SCLC treatment through in vitro experiments.

MATERIALS AND METHODS

We evaluated the influence of treatment with the LXR agonist T0901317 on cell proliferation and apoptosis in SCLC cell lines using cell viability, BrdU-ELISA, FACS, and western blot analyses. Moreover, the mechanism by which T0901317 inhibits SCLC cell proliferation was elucidated using qRT-PCR, western blot, a cholesterol quantification assay, and a genome editing technique.

RESULTS

We showed that cultivated SCLC cells expressed LXRβ and that an LXR agonist inhibited the proliferation of SCLC cells without toxicity to normal cells. Furthermore, the antitumoral effect of an LXR agonist on SCLC cells was attributed to the induction of ABCA1 by LXRβ activation, resulting in an increase in cellular cholesterol efflux via ABCA1.

CONCLUSION

The activation of LXRβ up-regulates ABCA1 expression, causing cholesterol depletion in cancer cells. This mechanism could be a novel target strategy for SCLC.

Endocrine secretory granule production is caused by a lack of REST and intragranular secretory content and accelerated by PROX1

Endocrine secretory granules (ESGs) are morphological characteristics of endocrine/neuroendocrine cells and store peptide hormones/neurotransmitters. ESGs contain prohormones and ESG-related molecules, mainly chromogranin/secretogranin family proteins. However, the precise mechanism of ESG formation has not been elucidated. In this study, we experimentally induced ESGs in the non-neuroendocrine lung cancer cell line H1299. Since repressive element 1 silencing transcription factor (REST) and prospero homeobox 1 (PROX1) are closely associated with the expression of ESG-related molecules, we edited the REST gene and/or transfected PROX1 and then performed molecular biology, immunocytochemistry, and electron and immunoelectron microscopy assays to determine whether ESG-related molecules and ESGs were induced in H1299 cells. Although chromogranin/secretogranin family proteins were induced in H1299 cells by knockout of REST and the induction was accelerated by the PROX1 transgene, the ESGs could not be defined by electron microscopy. However, a small number of ESGs were detected in the H1299 cells lacking REST and expressing pro-opiomelanocortin (POMC) by electron microscopy. Furthermore, many ESGs were produced in the REST-lacking and PROX1- and POMC-expressing H1299 cells. These findings suggest that a lack of REST and the expression of genes related to ESG content are indispensable for ESG production and that PROX1 accelerates ESG production.

Trial registration: Not applicable.

Histopathological evaluation of the effectiveness of oral Eppikajutsuto treatment for lymphatic malformation

BACKGROUND

Lymphatic malformation (LM) is a congenital disease caused by lymphatic vessel malformation. Although standard therapies for LMs are sclerotherapy and/or surgical excision, a new therapy using Japanese herbal medicine Eppikajutsuto (TJ-28) has been recently reported as clinically effective. We aimed to experimentally confirm the therapeutic effectiveness of TJ-28 for LMs.

METHODS

LM lesions were generated in the mesentery and peritoneum of mice by intraperitoneal injection of Freund's incomplete adjuvant. Mice with LMs were treated by gavage or dietary administration of TJ-28 for 2 months. Formalin-fixed paraffin-embedded tissue sections of mesentery and peritoneum tissues were histologically and immunohistochemically examined by focusing on lymph nodes and perinodal lymph vessels.

RESULTS

Multiple Freund's incomplete adjuvant-associated foreign-body granulomas were formed in the mesentery and peritoneum, resulting in congestion of lymph fluid and dilatation of lymph vessels. The numbers and sizes of lymph nodes were not significantly different between TJ-28-treated and control groups. However, the luminal areas of lymphatic vessels were reduced significantly in the TJ-28 treatment group by both gavage and dietary administrations.

CONCLUSION

TJ-28 conspicuously reduced congestion of lymph fluid. This is the first histopathological evaluation of LM model mice to study the effectiveness of oral TJ-28 treatment.

Aberrant Claudin-6-Adhesion Signaling Promotes Endometrial Cancer Progression via Estrogen Receptor α

Cell adhesion proteins not only maintain tissue integrity, but also possess signaling abilities to organize diverse cellular events in a variety of physiologic and pathologic processes; however, the underlying mechanism remains obscure. Among cell adhesion molecules, the claudin (CLDN) family is often aberrantly expressed in various cancers, but the biological relevance and molecular basis for this observation have not yet been established. Here, we show that high CLDN6 expression accelerates cellular proliferation and migration in two distinct human endometrial cancer cell lines in vitro. Using a xenograft model, we also revealed that aberrant CLDN6 expression promotes tumor growth and invasion in endometrial cancer tissues. The second extracellular domain and Y196/200 of CLDN6 were required to recruit and activate Src-family kinases (SFK) and to stimulate malignant phenotypes. Knockout and overexpression of ESR1 in endometrial carcinoma cells showed that the CLDN6-adhesion signal links to estrogen receptor α (ERα) to advance tumor progression. In particular, aberrant CLDN6-ERα signaling contributed to collective cell behaviors in the leading front of endometrial cancer cells. Importantly, we demonstrate that CLDN6/SFK/PI3K-dependent AKT and SGK (serum- and glucocorticoid-regulated kinase) signaling in endometrial cancer cells targets Ser518 in the human ERα to activate ERα transcriptional activity in a ligand-independent manner, thereby promoting tumor progression. Furthermore, CLDN6, at least in part, also regulated gene expression in an ERα-independent manner. IMPLICATIONS: The identification of this machinery highlights regulation of the transcription factors by cell adhesion to advance tumor progression.

Cell adhesion signals regulate the nuclear receptor activity

Cell adhesion is essential for proper tissue architecture and function in multicellular organisms. Cell adhesion molecules not only maintain tissue integrity but also possess signaling properties that contribute to diverse cellular events such as cell growth, survival, differentiation, polarity, and migration; however, the underlying molecular basis remains poorly defined. Here we identify that the cell adhesion signal initiated by the tight-junction protein claudin-6 (CLDN6) regulates nuclear receptor activity. We show that CLDN6 recruits and activates Src-family kinases (SFKs) in second extracellular domain-dependent and Y196/200-dependent manners, and SFKs in turn phosphorylate CLDN6 at Y196/200. We demonstrate that the CLDN6/SFK/PI3K/AKT axis targets the AKT phosphorylation sites in the retinoic acid receptor γ (RARγ) and the estrogen receptor α (ERα) and stimulates their activities. Interestingly, these phosphorylation motifs are conserved in 14 of 48 members of human nuclear receptors. We propose that a similar link between diverse cell adhesion and nuclear receptor signalings coordinates a wide variety of physiological and pathological processes.

P3365Relationship between early diastolic intra-ventricular pressure gradient shortly after aortic valve closure estimated by vector flow mapping and left ventricular diastolic untwisting rate in humans

Background

Early diastolic suction is an important determinant of early diastolic function. Previous studies using color Doppler M-mode and speckle-tracking echocardiography have shown left ventricular (LV) early diastolic LV untwisting rate is directly related to LV intra-ventricular pressure gradient (IVPG) between LV base and apex during early diastole. Recent introduction of vector flow mapping (VFM) using combination of color Doppler and speckle-tracking echocardiography provides noninvasive and feasible assessment of early diastolic IVPG shortly after aortic valve closure including isovolmic relaxation period (ED-IVPG) in humans. However, relationship between VFM–derived ED-IVPG and early diastolic LV untwisting rate has not been well investigated.

Purpose

The purpose of this study was to examine relationship between ED-IVPG estimated by VFM and LV untwisting rate by speckle-tracking echocardiography.

Methods

The study population consists of 66 patients without segmental wall motion abnormality, significant valvular diseases, and atrial fibrillation who underwent echocardiography for evaluation of LV function (age: 60±15 years, LVEF: 49±16%). From the apical long-axis views by color Doppler echocardiography, we analyzed peak ED-IVPG between LV base and apex just after aortic valve closure (figure) using commercially available VFM analysis software (DAS-RS1, Hitachi). We assessed peak early diastolic LV untwisting rate and LV torsion from LV basal and apical short-axis view by speckle-tracking echocardiography. We evaluated correlation between ED-IVPG and LV untwisting rate. We also evaluated correlation between ED-IVPG and peak systolic LV torsion, LV end-diastolic (EDV) and end-systolic volumes (ESV), ejection fraction (EF), early diastolic velocity (E) of LV inflow, average early diastolic velocity (e') of mitral annulus, and average E/e'.

Results

In all the study patients, ED-IVPG was successfully and quickly evaluated. 1) ED-IVPG correlated well with peak LV untwisting rate (r=0.64, p<0.0001). 2) ED-IVPG significantly correlated with LV torsion, LVEDV, LVESV, and LVEF (r=0.47, r=−0.48, r=−0.46, and r=0.48, respectively, p<0.001). 3) There were no significant correlations between ED-IVPG and other indexes including E, average e', and average E/e'. According to receiver operating characteristic analysis, the best cut-off value of ED-IVPG for determining impaired LV untwisting rate (<80 degrees/s) was found at 0.42 mmHg (sensitivity 81%, specificity 76%, and area under the curve 0.86)

ED-IVPG measurement by VFM

Conclusions

The present results showed that noninvasive VFM-derived peak ED-IVPG shortly after aortic valve closure is related to early diastolic peak LV untwisting rate. ED-IVPG easily and quickly estimated by VFM may be used as an additional index for LV diastolic function.

A Remote Operating Slit Lamp Microscope System

Objectives: To develop a remote-operating slit lamp microscope system (the remote slit lamp) as the core for highly specialized ophthalmology diagnoses, and to compare the utility of this system with the conventional slit lamp microscope system (the conventional slit lamp) in making a diagnosis.

Methods: The remote slit lamp system was developed. Three factors were evaluated in comparison to the conventional slit lamp. The ability to acquire skills was investigated using a task loading system among specialists and residents in ophthalmology. Participants repeated a task up to ten times and the time required for each task was analyzed. The consistency of the two systems in making a diagnosis was investigated using eyes of patients with ocular diseases as well as healthy volunteers.

Results: The remote slit lamp is composed of a patient’s unit and ophthalmologist’s unit connected by high-speed internet. The two units share images acquired by the slit lamp in addition to the images and voices of patients and ophthalmologists. Both ophthalmology specialists and residents could minimize the completion times after several trials. The remote slit lamp took more time than the conventional slit lamp. Both systems showed a high consistency in evaluations among eyes with healthy eyes or those with ocular diseases.

Conclusions: The remote slit lamp has a similar diagnostic ability, but required more examination time in comparison to the conventional slit lamp. The currently developed remote slit lamp has the potential to be employed for telemedicine purposes in the field of ophthalmology.

Expression of liver X receptors in normal and refractory carcinoma tissues of the human lung and pancreas

Liver X receptors (LXRs) participate not only in maintaining cholesterol homeostasis but also in controlling cellular growth in many types of normal and tumor cells. We previously reported that LXRα was aberrantly expressed in human oral squamous cell carcinoma (HOSCC) tissues and cell lines, and that LXR stimulation led to significant reduction of proliferation of HOSCC cells via accelerating cholesterol efflux. Since LXRs and downstream proteins involved in cholesterol metabolism could be also applied as therapeutic targets in small cell lung carcinoma (SCLC) and pancreatic ductal adenocarcinoma (PDAC), we herein analyzed the distribution of LXR proteins in these refractory cancers as well as in normal human lung and pancreatic tissues. LXRβ was observed in ciliated epithelial cells, bronchial gland epithelia, type II alveolar epithelia and alveolar macrophages of the lung, and was less expressed in bronchial basal cells and type I alveolar epithelia. In addition, LXRβ was detected in epithelium of the pancreatic duct and acinar cells of the pancreas, and was weakly expressed in pancreatic islet cells. By contrast, LXRα expression was restricted to alveolar macrophages, and was not evident in any types of epithelial cells in the lung and pancreas. We also demonstrated that LXRβ but not LXRα was abundantly expressed in nine cases of SCLC and twenty cases of PDAC tissues. These findings provide basic information for evaluating the efficacy of LXR-targeted treatment in SCLC and PDAC.

PKA activation and endothelial claudin-5 breakdown in the schizophrenic prefrontal cortex

Schizophrenia is thought to be caused by a combination of genetic and environmental factors; however, its pathogenesis remains largely unknown. Here, we focus on the endothelial tight-junction protein claudin-5 (CLDN5), because the CLDN5 gene is mapped to the schizophrenia-associated 22q11.2 deletion region, and a single nucleotide polymorphism in the CLDN5 locus is also linked to schizophrenia. We show, by RT-qPCR and immunohistochemistry, that the expressions of CLDN5 mRNA and protein are significantly increased and decreased, respectively, in the schizophrenic prefrontal cortex (PFC) compared with control PFC. These changes were not observed in the schizophrenic visual cortex (VC), and neither the density nor diameter of the CD34-positive microvessels was altered in the schizophrenic PFC or VC. Interestingly, protein kinase A (PKA) was activated in the microvascular and perivascular regions of the schizophrenic PFC, and the pPKA-positive microvascular endothelial cells occasionally exhibited focal loss of CLND5. Since we previously demonstrated that cAMP induced CLDN5 mRNA expression and size-selective loosening of the endothelial barrier in PKA-independent and -dependent manners, respectively, a similar mechanism could contribute to the discrepancy between mRNA and protein expression of CLDN5 in the schizophrenic PFC. Taken collectively, these findings provide novel insights into the pathophysiology of schizophrenia.

Liver X receptor reduces proliferation of human oral cancer cells by promoting cholesterol efflux via up-regulation of ABCA1 expression

Liver X receptors (LXRs) contribute not only to maintain cholesterol homeostasis but also to control cell growth. However, the molecular mechanisms behind the LXR-mediated anti-proliferative effects are largely unknown. Here we show, by immunohistochemistry, that LXRα and LXRβ are differentially distributed in oral stratified squamous epithelia. By immunohistochemical and Western blot analyses, we also reveal that LXRα is abundantly expressed in human oral squamous cell carcinoma (HOSCC) tissues and cell lines. Cell counting, BrdU labeling and cell cycle assay indicated that LXR stimulation led to significant reduction of proliferation in HOSCC cells. Importantly, our study highlights, by using RNA interference, that the ATP-binding cassette transporter A1 (ABCA1)-accelerated cholesterol efflux is critical for the growth inhibitory action of LXRs in HOSCC cells. Moreover, we demonstrate that LXR activation reduces the growth of xenograft tumour of HOSCC cells in mice accompanied by the upregulation of ABCA1 expression and the decline of cholesterol levels in the tumour. These findings strongly suggested that targeting the LXR-regulated cholesterol transport, yielding in lowering intracellular cholesterol levels, could be a promising therapeutic option for certain types of cancers.

Serial magnetic resonance imaging study of posterior cruciate ligament reconstruction or augmentation using hamstring tendons

PURPOSE

The purpose of this study was to analyze serial changes in the magnetic resonance imaging (MRI) signals of autograft hamstrings single bundle posterior cruciate ligament (PCL) reconstruction and the effects of remnant preservation (augmentation).

MATERIAL AND METHODS

Twenty-two isolated PCL injuries were arthroscopically reconstructed or augmented with hamstring tendons. MRI scans were obtained at 3, 6, and 12 months, and prior to the second-look arthroscopy (average 20.7 months). The patients were divided into 2 groups by remnant preservation: five PCL reconstructions after PCL remnant resection (Group Rec) (23%), and 17 reconstructions preserving the remnant (Group Aug) (77%). The 22 patients were also divided in two groups depending on the location of the PCL tear. There were 9 knees with proximal tear (Type P) (41%) and 13 knees with distal tear (Type D) (59%). The signal intensity and fiber continuity of 4 zones (proximal, middle, distal intra-articular and tibial tunnel zones) were evaluated by the Mariani score.

RESULTS

The average MRI evaluation score gradually increased from 6 months through the final MRI. The intra-articular part of the graft exhibited slower maturation (12 months - final scan) as compared with the tibial tunnel (6-12 months). The distal zone underwent better maturation than the proximal or middle zones at all points. In the proximal zone, the score for Group Aug was significantly higher than Group Rec. In the proximal zone, the Type D score with a proximally-preserved remnant was significantly higher than Type P without a proximal remnant.

CONCLUSIONS

The hamstring tendons require more than 1 year to achieve low-signal intensity. PCL remnant has a beneficial effect on the maturation of the hamstring graft.

LEVEL OF EVIDENCE IV

therapeutic case series.

Association study of genetic variants on chromosome 7q31 with susceptibility to normal tension glaucoma in a Japanese population

The caveolin 1 to caveolin 2 (CAV1-CAV2) gene region on chromosome 7q31 has been reported to be associated with susceptibility to primary open angle glaucoma (POAG) and normal tension glaucoma (NTG) in previous studies. We investigated whether genetic variants in the CAV1-CAV2 region are associated with NTG in Japanese patients. Two hundred and ninety-two Japanese patients with NTG and 352 Japanese healthy controls were recruited. We genotyped three single-nucleotide polymorphisms; that is, rs1052990, rs4236601, and rs7795356, in the CAV1-CAV2 gene region and assessed the allelic diversity among cases and controls. The frequency of the minor allele (G) of rs1052990 was significantly decreased in NTG cases compared with controls (P=0.014, OR=0.71), whereas NTG or POAG cases had a significantly higher frequency of the allele than controls in previous studies. Conversely, rs7795356 did not show any significant association with NTG cases, and rs4236601 was monomorphic in the Japanese study population. Our findings did not correspond with previous positive results, suggesting that CAV1-CAV2 variants studied in the present study are not important risk factors for NTG susceptibility in all populations. Further studies are needed to elucidate the possible contribution of the CAV1-CAV2 region to the development of glaucoma.

The Enhancing Effect of -Cyclodextrin Inclusion on -Tocotrienol-dependent Negative Growth Control of Mesothelioma Cells in a Xenograft Model

Background: Malignant mesothelioma is an aggressive cancer with no effective treatment options. Of phytochemicals, tocotrienol (T3), a member of vitamin E, is one of the most potent anti-mesothelioma agents, but the effectiveness in vivo is quite limited, due to its low bioavailability. In this study, we investigated if the oral treatment of -T3 inclusion with -cyclodextrin (CD) could improve the bioavailability and anticancer activity of the T3.Findings: Using nude mice bearing MSTO-211H cells (a human malignant mesothelioma cell line), the effect of -T3 inclusion with -CD on -T3 level in tumor tissues, tumor growth, and its related mRNA levels were examined. The difference of tumor growth between the two groups had no statistical significance, but the latter showed a lower tendency compared with the former. In linked with this observation, the level of vascular endothelial growth factor mRNA required for in vivo tumor growth in -T3 inclusion with -CD group was lower than that in -T3 group, on the contrary, the level of -T3 level showed an opposite tendency.Conclusion: Our study demonstrated that the bioavailability of -T3 was improved by an oral administration of a novel -T3 inclusion complex with CD. Furthermore, the improvement of the bioavailability contributed to the increase of anticancer activity of -T3 in vivo.Key words: Anti-cancer agent, bioavailability, cyclodextrin, mesothelioma, tocotrienol.

Comparing approaches to screening for angle closure in older Chinese adults

AIMS

Primary angle-closure glaucoma is expected to account for nearly 50% of bilateral glaucoma blindness by 2020. This study was conducted to assess the performance of the scanning peripheral anterior chamber depth analyzer (SPAC) and limbal anterior chamber depth (LACD) as screening methods for angle closure.

METHODS

This study assessed two clinical populations to compare SPAC, LACD, and gonioscopy: the Zhongshan Angle-closure Prevention Trial, from which 370 patients were eligible as closed-angle participants and the Liwan Eye Study, from which 72 patients were selected as open-angle controls. Eligible participants were assessed by SPAC, LACD, and gonioscopy.

RESULTS

Angle status was defined by gonioscopy. Area under the receiver operating characteristic curve (AUROC) for SPAC was 0.92 (0.89-0.95) whereas AUROC for LACD was 0.94 (0.92-0.97). Using conventional cutoff points, sensitivity/specificity was 93.0%/70.8% for SPAC and 94.1%/87.5% for LACD. Sequential testing using both SPAC and LACD increased the specificity to 94.4% and decreased the sensitivity to 87.0%.

CONCLUSION

SPAC has significantly lower specificity than LACD measurement using conventional cutoffs but interpretation of the findings can be performed by modestly trained personnel.

Bowman-Birk protease inhibitor from soybeans enhances cisplatin-induced cytotoxicity in human mesothelioma cells

Malignant mesothelioma (MM) is an aggressive cancer with no effective treatment options. Enforced expression of the gap junction (GJ) component connexin 43 (Cx43) increases the sensitivity of MM cells to cisplatin. Bowman-Birk protease inhibitor (BBI) induces the restoration of Cx43 in several types of tumor cells. In this study, we examined the capability of BBI to enhance the cytotoxic effect of cisplatin in MM cells via the induction of Cx43. Human MM H28 cells were used. Cell viability was evaluated by a WST-1 assay and proteasomal activity was determined by fluorometric analysis. Protein and mRNA levels were determined by immunoblot analysis and real-time RT-PCR, respectively. GJ function mediated by Cx43 was evaluated using the scrape-loading method. BBI effectively inhibited H28 cell growth in a dose-dependent manner (200-400 μg/ml). In parallel with the growth inhibition, Cx43 levels (mRNA and protein) and GJ function were elevated by BBI treatment. Knockdown of BBI-induced Cx43 by an antisense nucleotide treatment almost cancelled the growth inhibition. BBI enhanced cisplatin-induced cytotoxicity in H28 cells, and down-regulation of Cx43 by the antisense nucleotide treatment abrogated the enhancing effect of BBI. The induction of Cx43 by BBI contributed to Src inactivation and subsequent induction of Bax. Furthermore, an Src inhibitor (SU6656) also enhanced cisplatin-induced cytotoxicity in H28 cells. These results suggest that BBI improves the cytotoxic efficacy of cisplatin in H28 cells via the inhibition of Src signaling.

Insulin-like growth factor binding protein-4 gene silencing in lung adenocarcinomas

Gene silencing by promoter hypermethylation plays an important role in molecular pathogenesis. We previously reported that insulin-like growth factor (IGF) binding protein-4 (IGFBP-4), which inhibits IGF-dependent growth, is expressed via early growth response-1 (EGR-1) and is often silenced in cultivated lung cancer cells. The purpose of the present study was to clarify clinicopathological factors associated with IGFBP-4 gene silencing in lung adenocarcinomas. Seventy-six surgically resected adenocarcinomas (20 well-, 35 moderately-, and 21 poorly-differentiated) were subjected to methylation-specific polymerase chain reaction (PCR) analysis for EGR-1-binding sites located in the IGFBP-4 promoter and immunohistochemistry for IGFBP-4, EGR-1, and Ki-67. Thirty-two adenocarcinomas (42%) revealed IGFBP-4 promoter hypermethylation, and the severity inversely correlated with the level of IGFBP-4 expression (P < 0.0001) and tumor differentiation (well versus poor, P = 0.0278; well/moderate versus poor, P = 0.0395). Furthermore, there was a negative correlation between Ki-67 labeling index and IGFBP-4 expression (P = 0.0361). These findings suggest that the expression of IGFBP-4 in adenocarcinoma cells in vivo is downregulated by epigenetic silencing in association with tumor differentiation, resulting in disruption of the mechanism of IGFBP-4-mediated growth inhibition.

Early growth response-1 induces and enhances vascular endothelial growth factor-A expression in lung cancer cells

Vascular endothelial growth factor-A (VEGF-A) is crucial for angiogenesis, vascular permeability, and metastasis during tumor development. We demonstrate here that early growth response-1 (EGR-1), which is induced by the extracellular signal-regulated kinase (ERK) pathway activation, activates VEGF-A in lung cancer cells. Increased EGR-1 expression was found in adenocarcinoma cells carrying mutant K-RAS or EGFR genes. Hypoxic culture, siRNA experiment, luciferase assays, chromatin immunoprecipitation, electrophoretic mobility shift assays, and quantitative RT-PCR using EGR-1-inducible lung cancer cells demonstrated that EGR-1 binds to the proximal region of the VEGF-A promoter, activates VEGF-A expression, and enhances hypoxia inducible factor 1alpha (HIF-1alpha)-mediated VEGF-A expression. The EGR-1 modulator, NAB-2, was rapidly induced by increased levels of EGR-1. Pathology samples of human lung adenocarcinomas revealed correlations between EGR-1/HIF-1alpha and VEGF-A expressions and relative elevation of EGR-1 and VEGF-A expression in mutant K-RAS- or EGFR-carrying adenocarcinomas. Both EGR-1 and VEGF-A expression increased as tumors dedifferentiated, whereas HIF-1alpha expression did not. Although weak correlation was found between EGR-1 and NAB-2 expressions on the whole, NAB-2 expression decreased as tumors dedifferentiated, and inhibition of DNA methyltransferase/histone deacetylase increased NAB-2 expression in lung cancer cells despite no epigenetic alteration in the NAB-2 promoter. These findings suggest that EGR-1 plays important roles on VEGF-A expression in lung cancer cells, and epigenetic silencing of transactivator(s) associated with NAB-2 expression might also contribute to upregulate VEGF-A expression.

Neuroendocrine cancer-specific up-regulating mechanism of insulin-like growth factor binding protein-2 in small cell lung cancer

Small cell lung cancer (SCLC) exhibits insulin-like growth factor-dependent growth. SCLC is the most aggressive among known in vivo lung cancers, whereas in vitro growth of SCLC is paradoxically slow as compared with that of non-SCLC (NSCLC). In this study, we demonstrate that SCLC cells overexpress insulin-like growth factor binding protein (IGFBP)-2 via NeuroD, a neuroendocrine cell-specific transcription factor. Chromatin immunoprecipitation, electrophoretic mobility shift, and IGFBP-2 promoter assays all revealed that NeuroD binds to the E-box in the 5'-untranslated region of IGFBP-2. A NeuroD transgene in both airway epithelial and NSCLC cells up-regulated the transcription of IGFBP-2 and retarded cell growth. Recombinant IGFBP-2 repressed the growth of both airway epithelial and NSCLC cells in a dose-dependent manner. A NeuroD-specific small interfering RNA repressed IGFBP-2 expression in SCLC, and neutralization of IGFBP-2 and an IGFBP-2-specific small interfering RNA increased SCLC cell growth. Pathological samples of SCLC also expressed IGFBP-2 abundantly, as compared with NSCLC, and showed only rare (8%) IGFBP-2 promoter methylation, whereas the IGFBP-2 promoter was methylated in 71% of adenocarcinomas and 29% of squamous cell carcinomas. These findings suggest that 1) SCLC has an IGFBP-2 overexpression mechanism distinct from NSCLC, 2) secreted IGFBP-2 contributes to the slow growth of SCLC in vitro, and 3) the epigenetic alterations in the IGFBP-2 promoter contribute to the striking differences in IGFBP-2 expression between SCLC and NSCLC in vivo.

Investigation of the association between the GLC3A locus and normal tension glaucoma in Japanese patients by microsatellite analysis

Purpose:

To investigate whether the GLC3A locus harboring the CYP1B1 gene is associated with normal tension glaucoma (NTG) in Japanese patients.

Materials and Methods:

One hundred forty-two Japanese patients with NTG and 101 Japanese healthy controls were recruited. Patients exhibiting a comparatively early onset were selected as this suggests that genetic factors may show stronger involvement. Genotyping and assessment of allelic diversity was performed on 13 highly polymorphic microsatellite markers in and around the GLC3A locus.

Results:

There were decreased frequencies of the 444 allele of D2S0416i and the 258 allele of D2S0425i in cases compared to controls (P = 0.022 and P = 0.034, respectively). However, this statistical significance disappeared when corrected (Pc > 0.05). We did not find any significant association between the remaining 11 microsatellite markers, including D2S177, which may be associated with CYP1B1, and NTG (P > 0.05).

Conclusions:

Our study showed no association between the GLCA3 locus and NTG, suggesting that the CYP1B1 gene, which is reportedly involved in a range of glaucoma phenotypes, may not be an associated factor in the pathogenesis of NTG.

Anthraquinone polyamines: novel channel blockers of N-methyl-d-aspartate receptors

Polyamines, in particular spermine, as well as some natural and synthetic polyamine derivatives have been found to be blockers of N-methyl-D-aspartate receptors. We developed novel, polyamine-based channel blockers to analyze the structure of NMDA receptors. Anthraquinone polyamines block NMDA receptors with some selectivity compared to other glutamate receptors. Results using mutant NR1 and NR2 subunits identified amino acid residues that influence blockade by anthraquinone polyamines. The head group (anthraquinone) may be positioned at the selectivity filter/narrowest constriction of the channel and the polyamine tail penetrates this constriction into the inner vestibule below the level of the selectivity filter. The results are consistent with other work showing that NR1 (Asn616) and NR2B (Asn616), but not NR2B (Asn615), make the narrowest constriction of NMDA channel, and that the M3 segments from the two subunits, which form the outer vestibule, are likely staggered relative to each other in the vertical axis of the channel.

Negative growth control of osteosarcoma cell by Bowman-Birk protease inhibitor from soybean; involvement of connexin 43

Bowman-Birk protease inhibitor (BBI) from soybean acts as a potential chemopreventive agent in several types of tumors. However, the mechanism is still unclear. The present study was undertaken to estimate a mechanism of BBI-dependent negative growth control of human osteosarcoma cell (U2OS cell). BBI had negative growth control of the cells via induction of connexin (Cx) 43, a tumor suppressor gene in U2OS cells. This negative growth control by BBI was abrogated under down-regulation of Cx43 induced by a Cx43 antisense nucleotide treatment. It was also found that the BBI-dependent induction of Cx43 was due to elevation of Cx43 mRNA and stabilization of Cx43 protein. Especially, BBI-dependent inhibition of chymotrypsin-like activity in proteasome contributed to stabilization of Cx43 protein. These results suggest that a major negative growth effect of BBI is based on the restoration of Cx43 expression in U2OS cells.

Polyamines in renal failure

The levels of polyamines (putrescine, spermidine and spermine) and polyamine oxidase in plasma of patients with chronic renal failure were determined. The level of putrescine was increased but the level of spermine was decreased in the plasma of these patients. The patients also had increased plasma polyamine oxidase activity leading to increased degradation of spermine. As acrolein was a major toxic compound produced from spermine by polyamine oxidase, the levels of free and protein-conjugated acrolein in plasma were also measured. Acrolein levels were enhanced in plasma of patients with chronic renal failure. The accumulated acrolein found as protein conjugates was equivalent to 170 microM, which was about 5-fold higher than in plasma of normal subjects. It was found that acrolein is mainly produced by spermine oxidase in plasma. An increase in putrescine, spermine oxidase and acrolein in plasma was observed in all cases such as diabetic nephropathy, chronic glomerulonephritis and nephrosclerosis. After patients with chronic renal failure had undergone hemodialysis, their levels of plasma polyamines, spermine oxidase and acrolein returned towards normal. It is likely that acrolein produced from spermine accumulates in the blood due to decreased excretion into urine and may function as a uremic "toxin".

Effect of non-steroidal anti-inflammatory ophthalmic solution on intraocular pressure reduction by latanoprost in patients with primary open angle glaucoma or ocular hypertension

AIM

To investigate the effects of a non-steroidal anti-inflammatory drug (NSAID) ophthalmic solution on latanoprost induced intraocular pressure (IOP) reduction in glaucoma patients.

METHODS

Examination was conducted on 16 eyes of 16 glaucoma patients who had been given only latanoprost for at least 6 weeks. The NSAID ophthalmic solution, sodium 2-amino-3-(4-bromobenzoyl) phenylacetate sesquihydrate, was additionally given for 12 weeks into one eye (NSAID group), while sodium hyaluronic acid ophthalmic solution was administered into the other eye (control group) in a double masked fashion. The IOP measurement was performed before the start of additional administration of ophthalmic solutions, 2, 4, 6, 8, 10, and 12 weeks after the start of additional administration, and 2, 4, and 6 weeks after discontinuing additional administration.

RESULTS

No significant difference was observed in the IOPs before additional administration of ophthalmic solution between the NSAID group and the control group. Following the additional administration of ophthalmic solution, IOP in the NSAID group was consistently higher than that in the control group, and a maximum difference in IOP between the two groups was 1.08 (SD 1.75) mm Hg (p = 0.03). This trend was observed even after additional administration was discontinued.

CONCLUSION

NSAID ophthalmic solution may partly affect IOP reduction by latanoprost.

Finding cases of angle-closure glaucoma in clinic setting using a newly developed instrument

PURPOSE

To validate the applicability of a newly developed, noncontact scanning peripheral anterior chamber depth analyzer (SPAC) for screening eyes at the risk of angle-closure glaucoma (ACG).

SUBJECTS AND METHODS

All glaucoma patients who visited the University of Yamanashi Hospital from February through May 2003 were enrolled, except those with aphakic eye or pseudophakic eye. Of the 552 enrolled patients, 48 with ACG or narrow angles requiring laser iridotomy (LI) were categorized as patients with high-risk ACG eyes, and those with open angle were categorized as patients with control eyes. In all, 20 patients with ACG or narrow angles requiring prophylactic LI, who were followed up by an independent private ophthalmic clinic, were enrolled for threshold analysis. Nonophthalmologists measured anterior chamber depth and the averaged values of three measurements were employed for analysis. Threshold analysis and discriminant analysis were employed for determining the sensitivity and specificity of SPAC for diagnosing eyes with high-risk ACG.

RESULTS

SPAC distinguished well the high-risk ACG eyes from the control eyes, and one of the most useful criteria for screening is as follows: any of the four measured points should exceed 95% confidence interval, and sensitivity and specificity should be 97.6 and 83.5%, respectively.

CONCLUSION

SPAC is thought to be useful for detecting eyes at the risk of ACG by nonophthalmologists.

Decrease in the S1 protein of 30-S ribosomal subunits in polyamine-requiring mutants of Escherichia coli grown in the absence of polyamines

The reason for the decrease of polypeptide-synthetic activity of 30-S ribosomal subunits obtained from two polyamine-requiring mutants of Escherichia coli, grown in the absence of polyamines, has been studied by analyzing the total and split proteins of 30-S subunits by disc gel and slab gel electrophoresis. It was concluded that the decrease of S1 protein in 30-S subunits was responsible for the decrease of polypeptide synthesis in polyamine-requiring mutants of E. coli grown in the absence of polyamines.

Crystallization and preliminary X-ray analysis of the primary receptor (PotD) of the polyamine transport system in Escherichia coli

The primary receptor (potD, M(r) = 39 000) of the polyamine transport system in Escherichia coli has been crystallized by the vapor-diffusion method. Two crystal forms were obtained in the presence of spermidine, and were examined by X-ray analysis. Form I crystals, which diffract to 2.5 A resolution, belong to the space group P2(1), with unit-cell dimensions a = 145.3, b = 69.1, c = 72.5 A and beta = 107.6 degrees. Four molecules are contained in an asymmetric unit. These form two dimers that are related to each other by a local translation of about half of the unit cell along the a axis. The two protein molecules in each dimer are similarly related by a local dyad. Form II crystals diffract to 1.8 A resolution and belong to the space group I4(1), with unit-cell dimensions a = b = 130.3 and c = 38.7 A. They contain one molecule per asymmetric unit.

Usefulness of peripheral anterior chamber depth assessment in glaucoma screening

PURPOSE

This study was conducted to determine the usefulness of peripheral anterior chamber depth assessment in angle-closure glaucoma (ACG) screening in Japanese subjects.

SUBJECTS AND METHODS

The subjects were 14,779 adults 40 years old or older. Eyes having peripheral anterior chamber depth that is 1/4 the peripheral corneal thickness (van Herick's classification: grade 2) and less than 1/4 the peripheral corneal thickness (van Herick's classification: grade 1) were extracted as narrow angle eyes, and those eyes were further examined.

RESULTS

Of 14,779 subjects, 923 eyes of 505 subjects were diagnosed as narrow angle eyes (3.4%). Narrow angle eyes were observed in 4.9% of female subjects and 1.9% of male subjects, indicating a significantly higher frequency in women. The percentage of narrow angle eyes increased with age. Among the narrow angle eyes, 61 eyes of 32 subjects were diagnosed with ACG suspect (6.5%). In contrast to the frequency of ACG suspect in eyes classified as grade 1, according to van Herick's classification, being 17.9%, that in eyes classified as grade 2 was significantly lower at 5.6%.

CONCLUSION

Since the incidence of ACG suspect increases as the peripheral anterior chamber depth decreases, caution for the peripheral anterior chamber depth is required for the ACG screening.

A newly developed peripheral anterior chamber depth analysis system: principle, accuracy, and reproducibility

AIM

To develop a new, non-contact system for measuring anterior chamber depth (ACD) quantitatively, and to investigate its accuracy as well as interobserver and intraobserver reproducibility.

METHODS

The system scanned the ACD from the optical axis to the limbus in approximately 0.5 second and took 21 consecutive slit lamp images at 0.4 mm intervals. A computer installed program automatically evaluated the ACD, central corneal thickness (CT), and corneal radius of curvature (CRC) instantly. A dummy eye was used for investigating measurement accuracy. The effects of CT and CRC on the measurement results were examined using a computer simulation model to minimise measurement errors. Three examiners measured the ACD in 10 normal eyes, and interobserver and intraobserver reproducibility was analysed.

RESULTS

The ACD values measured by this system were very similar to theoretical values. Increase of CRC and decrease in CT decreased ACD and vice versa. Data calibration using evaluated CT and CRC successfully reduced measurement errors. Intraobserver and interobserver variations were small. Their coefficient variation values were 7.4% (SD 2.3%) and 6.7% (0.7%), and these values tended to increase along the distance from the optical axis.

CONCLUSION

The current system can measure ACD with high accuracy as well as high intraobserver and interobserver reproducibility. It has potential use in measuring ACD quantitatively and screening subjects with narrow angle.

Quantitative evaluation of changes in anterior segment biometry by peripheral laser iridotomy using newly developed scanning peripheral anterior chamber depth analyser

AIM

Using the newly developed scanning peripheral anterior chamber depth analyser (SPAC), the effects of peripheral laser iridotomy (PLI) on peripheral anterior chamber depth (PACD) were determined quantitatively as was the association between PACD and chronic elevation of intraocular pressure (IOP) after PLI.

METHODS

16 eyes of 15 patients with acute primary angle closure glaucoma (PACG) attack, 14 eyes of 14 patients with narrow angle and PACG attack in their fellow eyes, and 13 eyes of seven patients with chronic angle closure glaucoma (CACG) were enrolled. The SPAC scanned the anterior ocular segment from the optical axis to the limbus and took 21 consecutive slit lamp images at 0.4 mm intervals. A computer installed program automatically evaluated the PACD and the averaged values of three measurements were employed for analysis.

RESULTS

PLI significantly increased PACD and changed the iris contour from convex to flat or concave in all the enrolled eyes. The extent of the PLI induced PACD increase was enhanced with increasing distance from the optical axis. Comparing PACDs after PLI, eyes that received prophylactic PLI showed the greatest extent of PLI induced PACD increase, followed by eyes with CACG and eyes with PACG attack. The PACD of eyes with PACG attack was almost the same as that of the fellow eyes of PACG attack before prophylactic PLI. Eyes with PACG attack showed poorer IOP control after PLI than eyes with narrow angle and CACG with PLI.

CONCLUSIONS

PLI significantly increases PACD and the small PLI induced opening of PACD may contribute to chronic IOP elevation after PLI.

Comparison of iridial pigmentation between latanoprost and isopropyl unoprostone: a long term prospective comparative study

AIM

To compare incidence of iridial pigmentation prospectively induced by long term treatment with latanoprost and isopropyl unoprostone (hereafter, unoprostone) in Japanese patients with glaucoma.

METHODS

Patients with glaucoma treated with prostaglandin (PG) related ophthalmic solutions were sequentially enrolled. Patients treated for more than 30 months with PG related ophthalmic solutions were subjected to analysis. The entry criteria were no history of intraocular surgery, laser iridotomy, and/or laser trabeculoplasty within 12 months before and after the enrolment; and no history of uveitis; no changes in antiglaucoma drugs within 6 months before and after the enrolment. Photographs of the irides were taken under the same conditions and three glaucoma specialists evaluated the iridial pigmentation with masking of patient information. The correlation of iridial pigmentation with the background factors and the reduction of intraocular pressure (IOP) before and after the treatment were investigated.

RESULTS

48 eyes in 48 patients satisfied the enrolment criteria (25 eyes in the latanoprost group, 23 eyes in the unoprostone group). At the end of the follow up period, iridial pigmentation was present in 15 patients (60.0%) in the latanoprost group and seven patients (30.4%) in the unoprostone group. The correlation between development of iridial pigmentation and age, sex, concurrent use of other ophthalmic solutions, and IOP reduction was not significant.

CONCLUSIONS

The incidence of iridial pigmentation induced by latanoprost or unoprostone is high in the case of long term treatment. Iridial pigmentation did not affect PG related ophthalmic solution induced IOP reduction.

Agreement between frequency doubling perimetry and static perimetry in eyes with high tension glaucoma and normal tension glaucoma

AIMS

To investigate the agreement in results between frequency doubling technology (FDT) and the conventional automated static perimeter in eyes with normal tension glaucoma (NTG) and high tension glaucoma (HTG).

METHODS

72 eyes of 36 patients, who had two or more experiences with the Humphrey field analyser (HFA) program C30-2, were examined with the screening C-20-1 program of FDT. The result of FDT at each of the 17 stimulus points was graded as one of four categories. 58 out of 76 test points of HFA were assigned to one of the 17 clusters corresponding to FDT test points. Each cluster was represented as the lowest (scotoma of HFA) or the highest (threshold of HFA) probability symbol of total deviation (TD) of the HFA test points included in the cluster. The agreement between scotoma/threshold of HFA and FDT results was evaluated for NTG and HTG.

RESULTS

In a total of 65 eyes, the Spearman coefficients between the FDT and HFA (threshold/scotoma of HFA) were 0.599 and 0.515 (p<0.0001), respectively. In the HFA mean deviation matched 20 HTG eyes and 20 NTG eyes, the number of points with abnormal FDT results were 102 and 62 in eyes with HTG and NTG, respectively. The eyes with HTG had more abnormal FDT results than NTG eyes (p=0.0014, Mann-Whitney U test). The kappa coefficient between FDT and threshold of HFA in eyes with HTG and NTG was 0.288 and 0.520, respectively, and the agreement between FDT and scotoma of HFA was 0.480 and 0.439, respectively.

CONCLUSIONS

The best agreement of the results of FDT and HFA was observed in eyes with NTG using threshold of HFA. The eyes with HTG showed lower agreement with more abnormal points in FDT results, which suggests enough sensitivity of FDT in eyes with NTG, and higher sensitivity of FDT in eyes with HTG.

Acrolein produced from polyamines as one of the uraemic toxins

It is well known that the addition of spermine or spermidine to culture medium containing ruminant serum inhibits cellular proliferation. This effect is caused by the products of oxidation of polyamines that are generated by serum amine oxidase. Among the products, we found that acrolein is a major toxic compound produced from spermine and spermidine by amine oxidase. We then analysed the level of polyamines (putrescine, spermidine and spermine) and amine oxidase activity in plasma of patients with chronic renal failure. It was found that the levels of putrescine and the amine oxidase activity were increased, whereas spermidine and spermine were decreased in plasma of patients with chronic renal failure. The levels of free and protein-conjugated acrolein were also increased in plasma of patients with chronic renal failure. An increase in putrescine, amine oxidase and acrolein in plasma was observed in all cases such as diabetic nephropathy, chronic glomerulonephritis and nephrosclerosis. These results suggest that acrolein is produced during the early stage of nephritis through kidney damage and also during uraemia through accumulation of polyamines in blood due to the decrease in their excretion into urine.

Effect of non-steroidal anti-inflammatory ophthalmic solution on intraocular pressure reduction by latanoprost

AIM

To investigate the effects of a non-steroidal anti-inflammatory drug (NSAID) ophthalmic solution on latanoprost induced intraocular pressure (IOP) reduction using normal volunteers.

METHODS

This study was conducted as a prospective and observer masked clinical trial. 13 normal volunteers were enrolled. After measurement of basal IOP and ophthalmic examination, latanoprost ophthalmic solution was initially administered to both eyes once daily. Four weeks later, an NSAID ophthalmic solution, sodium 2-amino-3-(4-bromobenzoyl) phenylacetate sesquihydrate (refer to bromfenac sodium hydrate), was co-administered to one randomly selected eye (NSAID group) twice daily for 2 weeks. The other eye was employed as a control (non-NSAID group). After withdrawal of the NSAID ophthalmic solution, latanoprost ophthalmic solution was continuously administered for another 2 weeks and was then withdrawn. After a 4 week washout, only bromfenac sodium hydrate ophthalmic solution was administered to the eyes of the NSAID group for 2 weeks. During the study period, ophthalmic examination, including IOP measurement was performed in an observer masked fashion.

RESULTS

Before initiation of bromfenac sodium hydrate, baseline IOPs of the non-NSAID group and the NSAID group were 15.73 (SD 1.97) mm Hg and 15.86 (2.06) mm Hg, respectively (p=0.88). Although latanoprost ophthalmic solution significantly reduced IOP in both groups, co-administration of bromfenac sodium hydrate significantly inhibited latanoprost induced IOP reduction compared with the non-NSAID group. The IOPs of the non-NSAID and NSAID groups were 10.18 (1.17) mm Hg and 11.63 (1.35) mm Hg with a 2 week co-administration, respectively (p <0.01). Withdrawal of bromfenac sodium hydrate ophthalmic solution diminished the difference between the two groups. Re-administration of bromfenac sodium ophthalmic solution only did not affect IOP.

CONCLUSION

These results indicate that NSAID ophthalmic solution may interfere with IOP reduction by latanoprost ophthalmic solution in normal volunteers and that we should take this into account when treating patients with glaucoma using latanoprost ophthalmic solution.

Human T lymphotropic virus type 1 infection influences hepatitis C virus clearance

To explore the effect of human T lymphotropic virus type 1 (HTLV-1) infection on hepatitis C virus (HCV) infection, a survey for these viral infections was conducted that involved 2280 residents in an area in which HTLV-1 and HCV are endemic. The response of patients with HCV and HTLV-1 to interferon (IFN)-alpha treatment was also assessed. Antibody to HCV was detected in 13.8% of the residents tested, and antibody to HTLV-1 was detected in 15.4%. The prevalence of HCV RNA was significantly higher among residents who had antibodies to both HCV and HTLV-1 than in those who had antibodies to HCV only (P<.05). Sustained elimination of HCV RNA by IFN was significantly more frequent among patients with HCV alone than among those with HCV and HTLV-1. By logistic regression analysis, HTLV-1 infection was associated with nonresponse to IFN treatment. Thus, HTLV-1 infection affects the clearance, both natural and in association with IFN treatment, of HCV.

Polymyositis, pulmonary fibrosis and malignant lymphoma associated with hepatitis C virus infection

Polymyositis has been associated with various viral infections, and a spectrum of immune-related diseases may occur with hepatitis C (HCV) infection. Both polymyositis and HCV infection may be accompanied by pulmonary fibrosis. An association between polymyositis and malignancy has also been reported. We report a 55-year-old woman accompanied cryoglobulinemia with HCV infection and manifesting polymyositis, pulmonary fibrosis and malignant lymphoma. Steroid therapy was effective to improve interstitial pneumonia, polymyositis, and liver function.

Dual action of nitric oxide on purely isolated retinal ganglion cells

PURPOSE

The role of nitric oxide (NO) in the survival of retinal ganglion cells (RGCs) was investigated.

METHODS

RGCs were purely isolated from postnatal Sprague-Dawley rats by 2-step panning and were cultured in chemically defined serum free medium. An NO releaser, S-nitroso-N-acetylpenicillamine (SNAP: 500 microM, 250 microM, 100 microM, 10 microM, 1 microM, 100 nM, and 10 nM), an NO scavenger, 2-(4-carboxyphenyl)-4,4,5,5 tetramethylimidazoline-1-oxyl-3-oxide potassium salt (c-PTIO: 100 microM, 33 microM, 10 microM, 1 microM), mixture of 100 microM SNAP and 33 microM c-PTIO, N(G)-nitro-L-arginine methyl ester (L-NAME: 10 mM, 5 mM, 500 microM, 100 microM or 10 microM), or their vehicles were added to the medium of pure RGC culture for 48 hr. Survival rates of small and large RGCs were determined separately by flow cytometry.

RESULTS

At > or = 100 microM, SNAP significantly reduced RGC survival in a concentration dependent manner. At < or = 41 microM, SNAP significantly increased survival, particularly of large RGCs. c-PTIO and L-NAME reduced the survival rates concentration-dependently. A mixture of 100 microM SNAP and 33 microM c-PTIO significantly improved RGC survival compared with when they were added on their own.

CONCLUSIONS

These results indicate that NO exhibits neuroprotective and neurotoxic actions on RGCs and that low concentrations of NO may be beneficial for the survival of neonatal RGCs in vitro.

Effects of retinal glial cells on isolated rat retinal ganglion cells

PURPOSE

The effect of retinal glial cells on retinal ganglion cell (RGC) survival was investigated in cocultures of pure, isolated retinal glial cells with pure, isolated RGCs.

METHODS

RGCs from 2-day-old rats were cocultured for 48 hours, avoiding direct contact between cell types, with either nonconfluent retinal glial cells from 3-day-old rats or confluent retinal glial cells from 3-day-old, 12-day-old, or 1-year-old rats. Survival of RGCs was evaluated by flow cytometry. Amino acids were determined in culture medium. The effects of glutamate antagonists, 6-cyano-7-nitroquinoxaline-2,3-dione and MK801, a nitric oxide (NO) scavenger, 2-(4-carboxyphenyl)-4,4,5,5tetramethylimidazoline-1-oxyl-3-oxide potassium salt (c-PTIO), and an NO synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), were examined.

RESULTS

Nonconfluent retinal glial cells significantly reduced the survival of small and large RGCs, but confluent retinal glial cells reduced the survival of only small RGCs, regardless of the rat's age at the time of retinal glial cell harvesting. Profiles of some amino acids significantly varied, depending on the culture condition. Cocultures of RGCs with nonconfluent retinal glial cells released significantly more glutamate into the medium than cocultures of RGCs with confluent retinal glial cells or RGCs in pure culture. The glutamate antagonists improved the survival of RGCs cocultured with nonconfluent retinal glial cells, especially when the two were administered in combination, and in the case of large RGCs. c-PTIO and L-NAME, also improved the survival of RGCs cocultured with nonconfluent retinal glial cells.

CONCLUSIONS

Adverse effects of retinal glial cells on the survival of RGCs varied by size of the RGCs and retinal glial cell confluence. Glutamate and NO may be involved in retinal glial cell-related antisurvival effects.

Iridial pigmentation induced by latanoprost ophthalmic solution in Japanese glaucoma patients

PURPOSE

To investigate the incidence of iridial pigmentation induced by latanoprost ophthalmic solution in Japanese glaucoma patients by a prospective and observer-masked study.

PATIENTS AND METHODS

Sixty-nine eyes of 69 glaucoma patients were included. Patients who had undergone intraocular surgery, laser trabeculoplasty, and laser iridotomy within 12 months before enrollment, and patients with history of uveitis and any changes in antiglaucoma drugs within 6 months before enrollment were excluded. Iridial photographs were taken by one examiner under the same conditions at 1, 3, and 6 months after the initiation of latanoprost treatment. Three glaucoma specialists, masked of patient information, independently assessed the iridial pigmentation. Cases with iridial pigmentation diagnosed by three specialists were categorized as showing a definite increase in iridial pigmentation.

RESULTS

A definite increase in iridial pigmentation occurred in 3.5%, 9.7%, and 35.0% of eyes within 1, 3, and 6 months of treatment, respectively. Age, gender, or concomitantly used eyedrops did not significantly influence the incidence of iridial pigmentation within 6 months of instillation. A reduction of intraocular pressure by latanoprost did not differ significantly between patients with and without iridial pigmentation.

CONCLUSION

The incidence of iridial pigmentation by latanoprost ophthalmic solution in Japanese patients was higher than previously reported values in pigmented races.

Safety of ozonated solution as an antiseptic of the ocular surface prior to ophthalmic surgery

PURPOSE

To evaluate the safety of an ozonated solution as an antiseptic of the ocular surface prior to ophthalmic surgery.

METHODS

In experiment 1, a primary culture of rabbit corneal epithelium was established. Then, 0, 4 and 10 ppm ozonated solution and 1.25% povidone-iodine, respectively, were applied to confluent cells on collagen-coated filter inserts (Millicell-CM) for 10 min followed by replacement with fresh medium. The transepithelial electrical resistance (TER), which is a good indicator of cell barrier function, was sequentially measured for 30 min. In experiment 2, adult pigmented rabbit eyes were washed with 20 ml of 4 ppm ozonated solution, 1.25% povidone-iodine solution or saline. Slitlamp examinations were performed before and after washing.

RESULTS

In experiment 1, 4 ppm ozonated solution did not change the TER as compared with the control. 10 ppm ozonated solution and 1.25% povidone-iodine similarly reduced the TER values significantly as compared with those of the control and 4 ppm ozonated solution. In experiment 2, 4 ppm ozonated solution and saline showed mild superficial punctate keratitis (SPK) in 8.3% of eyes. However, 1.25% povidone-iodine resulted in mild SPK in 17% of eyes and moderate SPK in 25% of eyes. The prevalence of SPK between two groups was significantly different (p = 0.03).

CONCLUSION

Ozonated solution may be safe and a useful antiseptic of the ocular surface prior to ophthalmic surgery.

Isopropyl unoprostone increases the activities of matrix metalloproteinases in cultured monkey ciliary muscle cells

PURPOSE

The mechanism by which the prostaglandin F2alpha-related antiglaucoma compound isopropyl unoprostone (referred to as unoprostone) reduces intraocular pressure is largely unknown. Another prostaglandin F2alpha-related compound, latanoprost, influences the activities of matrix metalloproteinases in ciliary muscle. Unoprostone ophthalmic solution is metabolized to oxidized metabolites, mainly M1 and M2, in the eye. The aim of this study was to investigate whether intraocular metabolites of unoprostone, M1 and M2, change the metalloproteinase activity in cultured monkey ciliary muscle cells.

MATERIALS AND METHODS

Monkey ciliary muscle cells and trabecular meshwork cells were grown separately to confluence in monolayer cell cultures. M1 (10 nM, 100 nM, or 1 microM), M2 (10 nM, 100 nM, or 1 microM), 100 nM prostaglandin F2alpha, or vehicle solutions were added to each culture medium for 48 hours. The media were then assayed to measure metalloproteinase activities quantitatively by means of substrate zymography.

RESULTS

Compared with the vehicle controls, M1, M2, and prostaglandin F2alpha significantly increased the metalloproteinase-2 activity in cultured ciliary muscle cells in a dose-dependent manner, but did not affect the metalloproteinase-2 activity in cultured trabecular meshwork cells. All experimented prostaglandins slightly increased metalloproteinase-9 activity in ciliary muscle cells, although these changes were not significant.

CONCLUSIONS

The current results show that unoprostone influences the metabolism of the extracellular matrix in the ciliary muscle and that remodeling of the extracellular matrix in the ciliary muscle may be a possible mechanism by which unoprostone ophthalmic solution reduces intraocular pressure.

Properties of a revertant of Escherichia coli viable in the presence of spermidine accumulation: increase in L-glycerol 3-phosphate

Escherichia coli CAG2242 cells are deficient in the speG gene encoding spermidine acetyltransferase. When these cells were cultured in the presence of 0.5 to 4 mM spermidine, their viability was greatly decreased through the inhibition of protein synthesis by overaccumulation of spermidine. When the cells were cultured with a high concentration of spermidine (4 mM), a revertant strain was obtained. We found that a 55-kDa protein, glycerol kinase, was overexpressed in the revertant and that synthesis of a ribosome modulation factor and the RNA polymerase sigma(38) subunit, factors important for cell viability, was increased in the revertant. Levels of L-glycerol 3-phosphate also increased in the revertant. Transformation of glpFK, which encodes a glycerol diffusion facilitator (glpF) and glycerol kinase (glpK), to E. coli CAG2242 partially prevented the cell death caused by accumulation of spermidine. It was also found that L-glycerol 3-phosphate inhibited spermidine binding to ribosomes and attenuated the inhibition of protein synthesis caused by high concentrations of spermidine. These results indicate that L-glycerol 3-phosphate reduces the binding of excess amounts of spermidine to ribosomes so that protein synthesis is recovered.

Expression of thyroid hormone receptor betaA gene assayed by transgenic Xenopus laevis carrying its promoter sequences

The responsiveness of thyroid hormone responsive element (TRE)-containing promoter sequence to thyroid hormone (TH) was studied utilizing Xenopus laevis carrying a transgene containing 5'-upstream region of TRbetaA1 gene and green fluorescent protein (EGFP) gene. EGFP-expression was seen first in neurulae, which continued to stage 45, then became weak, and again started to increase at the prometamorphic stage, culminating at the metamorphic climax stage. Immunohistochemistry identified eyes, viscera, and muscles as the EGFP-expressing larval tissues. The treatment of premetamorphic tadpoles with TH induced the precocious EGFP-expression. We also showed that the transgenic Xenopus adults were responsive to exogenous TH, a high responsiveness being seen in brain, small intestine, kidney, and bone. TRbeta-expression in the embryo, larva, and adult was verified by Western blotting. Thus, TH not only regulates the metamorphosis, but also might play some biological role(s) in embryos and adults.