Transmembrane topography of the 100-kDa a subunit (Vph1p) of the yeast vacuolar proton-translocating ATPase

The membrane topography of the yeast vacuolar proton-translocating ATPase a subunit (Vph1p) has been investigated using cysteine-scanning mutagenesis. A Cys-less form of Vph1p lacking the seven endogenous cysteines was constructed and shown to have 80% of wild type activity. Single cysteine residues were introduced at 13 sites within the Cys-less mutant, with 12 mutants showing greater than 70% of wild type activity. To evaluate their disposition with respect to the membrane, vacuoles were treated in the presence or absence of the impermeant sulfhydryl reagent 4-acetamido-4'-maleimidylstilbene-2,2'-disulfonic acid (AMS) followed by the membrane permeable sulfhydryl reagent 3-(N-maleimidylpropionyl) biocytin (MPB). Three of the 12 active cysteine mutants were not labeled by MPB. The mutants E3C, D89C, T161C, S266C, N447C, K450C, and S703C were labeled by MPB in an AMS-protectable manner, suggesting a cytoplasmic orientation, whereas G602C and S840C showed minimal protection by AMS, suggesting a lumenal orientation. Factor Xa cleavage sites were introduced at His-499, Leu-560, and Pro-606. Cleavage at 560 was observed in the absence of detergent, suggesting a cytoplasmic orientation for this site. Based on these results, we propose a model of the a subunit containing nine transmembrane segments, with the amino terminus facing the cytoplasm and the carboxyl terminus facing the lumen.

Overexpression of striatal enriched phosphatase (STEP) promotes the neurite outgrowth induced by a cAMP analogue in PC12 cells

A cytoplasmic protein tyrosine phosphatase (PTPase) designated as striatal enriched phosphatase with a molecular weight of 46 kDa (STEP46) is highly expressed in striatal neurons with dopamine D1-receptors. To examine the hypothesis that STEP46 is involved in the neuronal functions modulated by the cyclic adenosine 3', 5'-monophosphate (cAMP)-signaling system, we introduced the complementary DNA of STEP46 into the pheochromocytoma cell line PC12, which exhibits neuronal differentiation characterized by neurite outgrowth in response to cAMP and nerve growth factor stimulation, and we established subclonal cell lines that constitutively overexpress STEP46 protein with PTPase activity. The subclones expressing STEP46 showed increased neurite outgrowth during differentiation induced by a cAMP analogue (dibutyryl cAMP). The positive regulatory role of STEP46 in the cAMP-induced neuronal differentiation of PC12 cells indicates that STEP46 may play a role in neuronal processes modulated by the cAMP-signaling cascade as a PTPase.

Combined NK1 and NK2 tachykinin receptor antagonists: synthesis and structure-activity relationships of novel oxazolidine analogues

We report herein the synthesis and structure-activity relationships of a series of novel oxazolidine analogues with regards to NK1 and NK2 tachykinin receptor binding affinity. Among this series of oxazolidine analogues, some compounds exhibited excellent high binding affinities for both NK1 and NK2 receptors. In addition, we describe the inhibitory effect in vivo on SP-induced airway vascular hyperpermeability and NKA-induced bronchoconstriction in guinea pigs.

Analysis of 1,992 patients with anorectal malformations over the past two decades in Japan. Steering Committee of Japanese Study Group of Anorectal Anomalies

BACKGROUND/PURPOSE

This report describes the results of a group study of the Japanese Study Group of Anorectal Anomolies (JSGA) to determine the relative incidence of specific types of anorectal anomaly in Japan, and includes discussion of rectourethral fistula regarding the relationship between the levels of the fistula and blind end of the rectum, low type deformity, rare types, and associated anomalies.

METHODS

A total of 1,992 patients (1,183 boys and 809 girls) registered from 1976 to 1995 were analyzed.

RESULTS

High-type deformities accounted for 26.0% of cases, intermediate 10.7%, low 57.2%, miscellaneous 4.5% and unclassified 1.8%. The most frequent deformity was male anocutaneous fistula (n = 364), followed by male rectourethral fistula (n = 333), and female anovestibular fistula (n = 241). There were 42 rectovesical fistulas in boys and 93 rectocloacal fistulas in girls. Covered anus complete occurred at the same frequency (10.1% of low deformities) as covered anal stenosis. In rectourethral fistula, the blind end of the rectum lay at or above the level of the P-C line in 40.3% of cases, at or above the M line in 39.6% and at the vicinity of the I line in 20.2%, respectively. There was no parallel relationship between the site of the fistula opening and the level of the rectal pouch. The overall incidence of patients having one or more associated anomalies was 45.2%: 70.6% in high deformity, 60.7% in intermediate, and 31.3% in low. The rate of association of Down's syndrome with deformities without fistula (40.3%) was significantly higher than with deformities with fistula (0.3%).

CONCLUSIONS

Rectovesical fistula and covered anus complete were not infrequent deformities in this series. We consider that at least 20% of rectourethral fistula should be categorized as intermediate or low deformity from the viewpoint of the position of the rectal pouch. A significant preponderance of Down's syndrome in the deformities without fistula suggests that further investigation of associated anomalies in comparision with other congenital diseases may provide insights into the pathogenesis of anorectal malformation in the field of molecular genetics.

Expression of p120 nucleolar proliferating antigen in human gliomas and growth suppression of glioma cells by p120 ribozyme vector

p120 is a nucleolar proliferating antigen which is expressed in tumor cells but not normal resting cells. The expression and localization of p120 in human gliomas were studied by Northern blot analysis, Western blot analysis and immunohistochemistry. All five of the glioma cell lines and all of the glioma specimens we investigated expressed p120 at both the mRNA and protein levels. p120 expression was not detected in adjacent brain tissues. A ribozyme vector was constructed to cleave the first GUC sequence in the coding region of p120 mRNA. This p120 ribozyme vector was transfected into the glioma cell line SF188, which expresses p120. The reduced p120 expression of the transfectant at both the mRNA and protein levels was confirmed. An MTT assay indicated that the transfected cells grew more slowly than control cells. These results indicate that i) p120 has an important role in the proliferation of gliomas, and ii) the ribozyme against p120 mRNA can suppress glioma cell growth.

Cloning and functional characterization of the 5'-flanking region of the human monocyte chemoattractant protein-1 receptor (CCR2) gene. Essential role of 5'-untranslated region in tissue-specific expression

The human monocyte chemoattractant protein-1 receptor designated hCCR2 is an essential co-receptor in cell entry by the human immunodeficiency virus as well as a receptor for monocyte chemoattractant protein-1, a member of the family of C-C chemokines that mediate monocyte chemotaxis. To elucidate the molecular mechanisms underlying the transcriptional regulation of hCCR2, we cloned and sequenced the hCCR2 gene; it was approximately 8 kilobase pairs in length and consisted of three exons divided by two introns. In the 5'-flanking region, there were the typical mammalian promoter consensus elements, a CAAT box and a TATA box, resulting in a single transcription initiation site. In addition, we found clustered tissue-specific cis-regulatory elements such as GATA consensus sequences, Oct-1 binding sequences, and CAAT/enhancer-binding protein binding sequences. Luciferase assays with various promoter deletions and gel mobility shift assays indicated that three cis-regulatory elements located within the region from -89 to +118 are required for basal activity in THP-1 cells. One element is an octamer sequence 36-base pair upstream from the TATA box; it binds mainly to Oct-1 and is capable of increasing transcriptional activity. The other two elements, which are tandem recognition sites of the CAAT/enhancer-binding protein family, are located in the 5'-untranslated region and account for the transcriptional activation as well as the tissue specificity of hCCR2.

Synthesis of 2-phenylbenzofuran derivatives as testosterone 5 alpha-reductase inhibitor

A series of 2-phenylbenzofuran derivatives with a carbamoyl, alkylamino, or alkyloxy group at the 5 or 6 position of the benzofuran ring were synthesized and evaluated for rat and human testosterone 5 alpha-reductase inhibitory activities in vitro. Against rat enzyme, the carbamoyl derivatives had more potent inhibitory activities than the alkylamino or alkyloxy derivatives, and the 6-carbamoyl derivatives tended to be more potent than the 5-carbamoyl derivatives. Against human enzyme, the 6-substituted derivatives had more potent inhibitory activities than the 5-substituted derivatives. The 6-carbamoyl and 6-alkylamino derivatives tended to show stronger inhibitory activities against human type 1 enzyme than against type 2 enzyme, but they were not largely selective.

Prognostic significance of the MIB-1 labeling index for patient with craniopharyngioma

Proliferative activity of 17 craniopharyngiomas were determined using an immunohistochemical method with monoclonal antibody MIB-1. A considerable variation of the MIB-1 labeling indices was found between the different tumors with a minimum of 0.4% and a maximum of 32.5% (median, 10.84%). The mean MIB-1 labeling index (LI) for 4 craniopharyngiomas that showed no evidence of recurrence (n=4) was 3.4 +/- 2.3%. This was significantly lower than that for craniopharyngiomas that showed recurrence and regrowth (13.2 +/- 7.7%) (n=13), based on the initial resected tumors. Statistical analysis reveal that craniopharyngiomas with an MIB-1 LI of 7% or more have a significantly high tendency for recurrence and regrowth during clinical course. Our data suggest that a MIB-1 LI greater than 7% may be a useful predictor of regrowth/recurrence of craniopharyngiomas and may be useful for planning of adjuvant therapy.

Bladder origin neuroblastoma detected by mass screening

Pelvic neuroblastoma is relatively rare and most are a presacral mass. We present a case of asymptomatic neuroblastoma arising from the dome of the bladder wall, detected by a mass screening program. Only 1 case of neuroblastoma originating from the bladder has been previously reported. Both the reported case and our present case arose from the dome of the bladder wall. The differential diagnosis for bladder tumor in children is discussed; although uncommon, neuroblastoma should be considered a probable choice, especially for tumors arising from the dome of the bladder wall.

Light-increased cGMP and K+ conductance in the hyperpolarizing receptor potential of Onchidium extra-ocular photoreceptors

The phototransduction mechanism of the extra-ocular photoreceptor cells Ip-2 and Ip-1 in the mollusc Onchidium ganglion was examined. Previous work showed that the depolarizing receptor potential of another extra-ocular photoreceptor cell, A-P-1 is produced by a decrease of the light-sensitive K+ conductance activated by a second messenger, cGMP and is inactivated by the hydrolysis of cGMP. Here, a hyperpolarizing receptor potential of Ip-2 or Ip-1 was associated with an increase in membrane conductance. When Ip-2 or Ip-1 was voltage-clamped near the resting membrane potential, light induced an outward photocurrent corresponding to the above hyperpolarization. The spectral sensitivity had a peak at 510 nm. The shift of reversal potentials of the photocurrent depended on the Nernst equation of K(+)-selective conductance. The photocurrent was blocked by 4-AP and L-DIL, which are effective blockers of the A-P-1 light-sensitive K+ conductance. These results suggested that the hyperpolarization is mediated by increasing a similar light-sensitive K+ conductance to that of A-P-1. The injection of cGMP or Ca2+ into a cell produced a K+ current that mimicked the photocurrent. 4-AP and L-DIL both abolished the cGMP-activated K+ current, while TEA suppressed only the Ca(2+)-activated K+ current. These results indicated that cGMP is also a second messenger that regulates the light-sensitive K+ conductance. The photocurrent was blocked by LY-83583, a guanylate cyclase (GC) inhibitor, but was unaltered by zaprinast, a phosphodiesterase (PDE) inhibitor. Together, the present results suggest that increasing the internal cGMP in Ip-2 or Ip-1 cells light-activates GC rather than inhibits PDE, thereby leading to an increase of the light-sensitive K+ conductance and the hyperpolarization.

Cadherin-8 protein expression in gray matter structures and nerve fibers of the neonatal and adult mouse brain

The topological distribution of mouse cadherin-8 protein in the neonatal and adult mouse brain was studied immunohistochemically using a rabbit antiserum. Cadherin-8 expression was restricted to several areas in neonatal brains constituting particular neural circuits, i.e. the limbic system, the basal ganglia-thalamocortical circuit, and the cerebellum and related nuclei. In addition, the nerve fibers linking some of the cadherin-8-positive areas, i.e. the habenulo-interpeduncular tract, decussation of the dorsal tegmentum, the medial longitudinal fasciculus, transverse pontine fibers, the brachium conjunctivum and the inferior cerebellar peduncle were cadherin-8 positive, as were the spinal tract of the trigeminal nerve, oculomotor nerve, facial nerve and trigeminal nerve. Cadherin-8 expression also showed a patch-like distribution in the intermediate gray layer of the superior colliculus, resembling acetylcholinesterase-rich patches in allocation. Segmentally organized cadherin-8-positive areas were found in the neonatal cerebellar Purkinje cell layer. Some nuclei and fibers in the brainstem and cerebellum, expressing cadherin-8 at neonatal stages, were also stained in the adult mouse brain. These findings suggest that cadherin-8 is involved in the formation of particular neural circuits by connecting areas expressing this molecule with positive nerve fibers, and indicate its possible implication in subdivisional organization in the superior colliculus and cerebellum.

Targeted gene transfer to corneal endothelium in vivo by electric pulse

A novel method of in vivo targeted gene transfer to intentionally selected areas of the corneal endothelium was developed. Plasmid DNA with the lacZ gene coding for beta-galactosidase was injected into the anterior chamber of adult Wistar rats, and eight pulses of electricity at intensities ranging from 5 to 40 V/cm were delivered for 50 ms to the cornea with a specially designed electric probe in order to determine the effect of gene transfer on the corneal endothelial cells. Gene expression was visualized by enzymatic color reaction using X-gal in enucleated eyes on days 1, 3, 7, 14 and 21 after gene transfer. The treated eyes were then photographed and the X-gal-positive areas were evaluated by an image analyzer. The ratios of the areas (X-gal-positive area/area of entire corneal endothelium x 100%) were then calculated to determine gene transfection efficiency. The expression of beta-galactosidase was clearly detected in the cytoplasm of the corneal endothelial cells as early as day 1 and lasted until day 21. The most intense gene expression was observed on days 1 and 3 (5.21% on day 1 and 6.45% on day 3). The expression of beta-galactosidase on day 3 was most evident following delivery of 20 V electric pulses (0.09% at 5 V, 0.03% at 10 V, 6.45% at 20 V). beta-Galactosidase expression was limited to the corneal endothelial cells in highly selected areas and no beta-galactosidase expression was detected in any other intra- or axtraocular tissues. In addition, no cell damage was apparent in the cornea and no inflammation was detected in any other intraocular tissues. Thus, low-voltage electric pulses successfully transferred the gene of interest to highly selective areas of the corneal endothelium without inducing any pathological changes. This targeted gene transfer method appears to have great potential for use in gene therapy for ocular diseases.

Pancreatoblastoma: optically clear nuclei in squamoid corpuscles are rich in biotin

Pancreatoblastoma is a rare pancreatic neoplasm that generally occurs in children and demonstrates unique histopathologic features, including squamoid corpuscles. We encountered five cases of pancreatoblastoma and unexpectedly found the presence of optically clear nuclei (OCN) only in tumor cells of squamoid corpuscles. Recent studies showed that OCN seen in some types of neoplastic and non-neoplastic tissues were rich in biotin and revealed false-positive immunostaining by the avidin-biotin peroxidase complex method. We conducted an investigation to see if the same were true for pancreatoblastoma. As a result, the OCN were positively stained when the tissue section was incubated with peroxidase-labeled avidin or streptavidin and developed in a chromogen solution. The reaction was completely blocked by pretreatment with free avidin. An identical nuclear staining pattern was observed by the indirect immunoperoxidase method with the antibiotin antibody. Ultrastructurally, the OCN were occupied by filamentous substructures of chromatin measuring approximately 10 to 12 nm in diameter. These results suggested to us that the OCN in pancreatoblastomas were part of the unique nuclear change in which abundant biotin accumulated in association with the characteristically arranged chromatin substructure. When immunostaining with biotin as the linkage agent is performed in pancreatoblastomas, the false positivity in the OCN should be kept in mind to avoid any misinterpretation of the results.

A case control study on risk factors involved in inflammatory breast recurrence after breast-conserving surgery

Recurrence that poses the biggest problem after breast-conserving surgery is local recurrence. Particularly, in the case of inflammatory breast recurrence which is rare but has a specific pathologic nature, it is important to elucidate the pathology and risk factors and to consider appropriate countermeasures. In the present study, we classified 133 cases of recurrence following breast-conserving surgery, collected from 18 key hospitals/institutes in Japan. Recurrence types were divided into three groups, namely, inflammatory breast recurrence, noninflammatory breast recurrence and distant metastasis only, and the risk factors involved in recurrence were investigated by the case control study allotting 2 controls to each case. The study population consisted of 9 cases of the inflammatory type, 64 cases of the noninflammatory type and 60 cases of distant metastasis. The significant risk factor for inflammatory breast recurrence was positive lymph node metastasis, which was significantly more frequent in lymphatic invasion-positive cases unlike in the distant metastasis group. The positive surgical margin and nonradiation therapy which have been shown to be significant risk factors for noninflammatory breast recurrence were entirely unrelated with inflammatory breast recurrence. In addition, the inflammatory-type recurrence time was as short as about 12 months irrespective of whether radiation therapy was performed or not. The inflammatory type was accompanied with local wide extension (cancerous embolus of the dermal lymphatic vessels), and distant metastasis (lymphangitis carcinomatosa) at the time of recurrence, and further surgery was impossible in most cases, with a significantly poorer prognosis than the other recurrence types. These findings suggest that this recurrence corresponds to the so-called 'occult' case of primary inflammatory breast carcinoma. We think it important to predict this recurrence by close pathological examination, particularly in patients with lymph node metastasis, and to consider appropriate measures.

Guanidinated casein hydrolysate stimulates pancreatic secretagogue release by direct action to the intestine in rats

Previously, we observed that pancreatic exocrine secretion was strongly enhanced after duodenal administration of guanidinated casein peptic hydrolysate (HGC) in rats with chronic bile-pancreatic juice (BPJ) diversion. Using a perifusion system of isolated dispersed rat intestinal mucosal cells, we investigated whether this phenomenon depends on a direct effect of protein on the intestine to release pancreatic secretagogues, such as cholecystokinin (CCK). Amylase release from isolated pancreatic acini was used as an assay to measure CCK or other pancreatic secretagogues in the effluents. Mucosal effluent with HGC stimulated amylase release from acini with or without soybean trypsin inhibitor (SBTI). Perifused effluent with low-concentrated SBTI did not stimulate amylase release. These results indicate that HGC stimulates release of pancreatic secretagogue from the intestinal mucosal cells independent of remaining trypsin activity in the isolated mucosa. Effluents with intact casein, its peptic digest, and homoarginine, which is a unique amino acid contained in HGC, were unable to stimulate amylase release from acini. Effluent with a high concentration of SBTI, which is rich in arginine residues, stimulated amylase release, but not with the same tryptic inhibitory effect of lima bean trypsin inhibitor, which is poor in arginine residues. These findings suggest that guanidyl residues in protein structure are responsible for release of pancreatic secretagogues from isolated intestinal mucosal cells. Finally, the increment of amylase release from pancreatic acini in response to the perifused effluent with HGC was eliminated in acini treated with a potent CCK antagonist, FK480. We conclude that in rats with BPJ diversion, HGC stimulates CCK release from the intestine by direct action on intestinal mucosa.

Impairment of cell adhesion by expression of the mutant neurofibromatosis type 2 (NF2) genes which lack exons in the ERM-homology domain

Neurofibromatosis 2 (NF2) is an inherited disorder characterized by a predisposition to multiple intracranial tumors. The protein encoded by the NF2 gene has striking similarities to ezrin, radixin and moesin (ERM) proteins which link membrane proteins to the cytoskeleton. Therefore, it can be speculated that the disruption of cytoskeletal organization by alterations in the NF2 gene is involved in the development of tumors. It has been reported that the majority of NF2 mutations were nonsense or frameshift mutations that result in premature termination of translation. To facilitate the detection of these mutations, we performed protein truncation test and found that 11 of 14 NF2 patients had truncational mutations (79%). Seven of the 11 patients (64%) had a splicing abnormality which lead to absence of exons in the ERM homology domain. To examine the biological significance of the exon-missing mutations in the ERM homology domain, we expressed the wild-type (wt-NF2) and the various mutant NF2s (mu-NF2s) in a fibroblast cell line by using both liposome-mediated transfection and nuclear microinjection of the expression plasmids. The wt-NF2 showed intense punctate staining in the perinuclear cytoplasm in addition to overall staining of the submembranous area, whereas the mu-NF2s lacking exons in the ERM homology domain showed granular staining at the perinuclear region without any accumulation at the submembrane region. Microinjection of wt-NF2 cDNA into the nucleus of VA13 cells revealed that wt-NF2 protein induced a progressive elongation of cell processes. Furthermore, cells that expressed mu-NF2 had decreased adhesion, which resulted in detachment from the substratum. These findings suggested that the exon-missing mutations in the ERM-homology domain may affect cell membrane-cytoskeleton signaling and consequently disrupt cell-to-cell or cell-to-matrix interaction.

IL-12 promotes the adhesion of NK cells to endothelial selectins under flow conditions

This study examined the adhesive interactions of peripheral blood NK cells with P- and E-selectin and analyzed the effect of IL-12 on the binding of NK cells to these selectins. P-selectin glycoprotein ligand-1 (PSGL-1) is expressed on most resting and IL-12-activated NK cells. However, the percentage of resting NK cells bound to P-selectin-IgG was 15%, and that of activated NK cells bound to P-selectin-IgG was 65%. Furthermore, the number of IL-12-activated NK cells bound to P-selectin-transfected Chinese hamster ovary cells was significantly higher than that of resting NK cells under flow conditions. These interactions were abolished by the incubation of these NK cells with anti-PSGL-1 (PL-1) mAb. Thus, PSGL-1/P-selectin interaction is important in the binding of resting and activated NK cells to P-selectin. NK cells express sialyl-Lewis(x) (sLe(x)) structure recognized by anti-sLe(x) mAb (KM-93), and IL-12 activation of NK cells increased the mean fluorescence intensity of KM-93-reactive NK cells. Adhesion of IL-12-activated NK cells to E-selectin-transfected Chinese hamster ovary cells was stronger than that of resting NK cells under flow conditions. These interactions were reduced markedly by incubation with anti-sLe(x) mAb. Thus, sLe(x) is the major ligand of resting and activated NK cells for E-selectin. These findings indicate that IL-12 stimulation of NK cells promotes their adhesion activity to endothelial selectins.

The involvement of calpain-dependent proteolysis of the tumor suppressor NF2 (merlin) in schwannomas and meningiomas

Neurofibromatosis type 2 (NF2) protein, also known as merlin or schwannomin, is a tumor suppressor, and NF2 is mutated in most schwannomas and meningiomas. Although these tumors are dependent on NF2, some lack detectable NF2 mutations, which indicates that alternative mechanisms exist for inactivating merlin. Here, we demonstrate cleavage of merlin by the ubiquitous protease calpain and considerable activation of the calpain system resulting in the loss of merlin expression in these tumors. Increased proteolysis of merlin by calpain in some schwannomas and meningiomas exemplifies tumorigenesis linked to the calpain-mediated proteolytic pathway.

Expression of CD44 adhesion molecules in intracranial germinomas

Adhesion molecules play a role in tumor growth, invasiveness, and the metastatic process. The expression of CD44 adhesion molecules in 11 intracranial germinoma specimens was investigated using anti-CD44 monoclonal antibody and immunohistochemical methods. In six of 11 specimens studied, CD44 antibodies were bound to the membrane of tumor cells; in five of six specimens, CD44 antigen was also present in the cytoplasm of tumor cells. The only three patients who showed CD44-positive expression in tumor cells, lymphocytes, and extracellular matrix (ECM) exhibited either cerebrospinal fluid dissemination or multiple tumors at different locations. In all 11 specimens, no expression of CD44 in normal glial cells or capillary endothelium was detected. According to the authors' findings, the expression of CD44 in intracranial germinomas is similar to that of gonadal seminomas. Analysis of the results further suggests the possibility that the expression of CD44 in intracranial germinoma tumor cells, lymphocytes, and ECM may contribute to tumor cell migration, adhesion to cerebrospinal fluid dissemination, and/or multiple tumor locations.

2(1H)-quinolinone derivatives as novel anti-arteriostenotic agents showing anti-thrombotic and anti-hyperplastic activities

In order to search for anti-arteriostenotic agents, a series of 2(1H)-quinolinone derivatives was synthesized and evaluated for anti-thrombotic activity and for anti-hyperplastic activity. From this series, (-)-6-[3-[3-cyclopropyl-3-[(1R,2R)-2-hydroxycyclohexyl]ureido]propoxy]-2 (1H)-quinolinone (1p, OPC-33509) was selected as the best candidate by balancing the efficacy on anti-thrombosis and anti-hyperplasia.