Expression of tumor necrosis factor alpha (TNFalpha) following transient cerebral ischemia

It has been considered that tumor necrosis factor alpha (TNFalpha) is participated in the Alzheimer's, and Parkinson's diseases, brain injury and brain ischemia. However, expression of TNFalpha after brain ischemia has not been demonstrated in detail. Therefore we examined the cellular expression of TNFalpha during and after transient middle cerebral artery occlusion (tMCAO) in mice by use of reverse transcriptase-polymerase chain reaction and immunohistochemical technique. TNFalpha mRNA expression was gradually increased in the neocortex of the ipsilateral hemisphere during ischemia and peaked at 1 hour after reperfusion. Then, the mRNA expression decreased and peaked again at 24 hours after reperfusion. TNFalpha-like immunoreactivities were observed in the process such as dendrite of neuron slightly before ischemia, and markedly increased in neurons in addition to the process of the ipsilateral hemisphere at 1 and 24 hours after ischemia. The results suggest that the expression of TNFalpha is up-regulated in the neurons after tMCAO. TNFalpha may induce ischemic neuronal cell death during ischemic insult.

Hippocampal heme oxigenase-1 in a murine cardiac arrest model

Heme oxygenase-1 (HO-1) is a member of the heat shock protein family (HSP-32). It responds to thermal stress in cultured glial cells. To our knowledge. nothing is known about the expression and response of the HO-1 in cerebral ischemia. Therefore, we show here the induction of HO-1 in the brain of mice after global cerebral ischemia. HO-1-like immunoreactivity was detected at 12, 24, and 48 hours after ischemia recirculation. The HO-1-like immunoreactive cells were observed in astrocytes in the hippocampal dentate gyrus and CA1. The peak level of HO-1-like immunoreactivity was found 48 hours after the recirculation. HO-1-like immunoreactivity was observed in GFAP-positive astrocytes by use of a double immunostaining method. These results provide direct evidence for the induction and localization of HO-1 immunoreactivity in vivo in a mouse cerebral ischemia. We suggest that HO-1, produced in astrocytes after ischemia-recirculation, may directly affect neurons to protect from cell death.

Enhancement of integrins by interleukin-1alpha, and their relationship with metastatic and invasive behavior of human pancreatic ductal adenocarcinoma cells

BACKGROUND AND OBJECTIVES

Adhesion and invasion of tumor cells to extracellular matrix (ECM) proteins play an important role in tumor metastasis formation. We investigated the enhancement of adhesive and invasive behavior to ECM proteins of human pancreatic cancer cells by interleukin-1alpha (IL-1alpha) to examine the mechanism of adhesion and invasion of metastatic human pancreatic cancer cells to ECM proteins.

METHODS

The enhancement of integrin subunits by IL-1alpha was examined by cellular enzyme-linked immunosorbent assay (CELISA) in two metastatic human pancreatic cancer cell lines (BxPC-3 and SW1990) and two nonmetastatic pancreatic cancer cell lines (PaCa-2 and PANC-1). In addition, assays of cancer cell adhesion and invasion to ECM proteins were performed to investigate whether increased integrin expression affected the invasive interaction between cancer cells and the putative integrin ECM ligands.

RESULTS

Expression of the alpha6 subunit by metastatic cancer cells was enhanced by IL-1alpha. Metastatic cancer cells also exhibited preferential adherence and invasion to laminin compared with nonmetastatic cancer cells, and this was enhanced by IL-1alpha.

CONCLUSIONS

The enhancement of alpha6beta1-integrin by Il-1alpha acting through IL-1RI, as well as the expression of alpha6beta1-integrin, plays an important role in metastasis formation in pancreatic cancer

Induction of capacitation and the acrosome reaction of boar spermatozoa by L-arginine and nitric oxide synthesis associated with the anion transport system

The aim of this study was to determine the effect of L-arginine on nitric oxide (NO) synthesis, capacitation and acrosome reaction of boar spermatozoa. Ejaculated boar spermatozoa were washed and then cultured in a bicarbonate:CO(2)-buffered medium, modified NCSU-37, for 2 h. At the end of the culture, the status of spermatozoa was determined. The presence of (0.1-2.0 mmol l(-1)) L-arginine in the culture medium induced an acrosome reaction as determined by fluorescein isothiocyanate-peanut agglutinin (FITC-PNA) and increased intracellular NO content, as quantified by a fluorescent indicator, diaminofluorescein-2 diacetate (DAF-2 DA). This stimulatory effect of L-arginine was neutralized by supplementation with an NO synthase inhibitor, N(omega)-nitro-L-arginine methyl ester (1 mmol l(-1)). However, the inactive enantiomorph, N(omega)-nitro-D-arginine methyl ester, did not affect the stimulatory effect of L-arginine. These results indicate that L-arginine induces an acrosome reaction through the NO signal pathway in boar spermatozoa. Furthermore, the stimulatory effect of L-arginine was inhibited in the presence of an anion transport inhibitor, 4-acetamido-4'-isothiocyano-stilbene-2,2'-disulphonic acid (SITS; 0.1 mmol l(-1)), whereas any responses of spermatozoa to caffeine were not inhibited by SITS. A stimulatory effect of L-arginine on capacitation and acrosome reaction of spermatozoa was also observed in modified NCSU37 medium by using a chlortetracycline fluorescence assay, but not in supplemented bicarbonate-free Tris-buffered medium. These results indicate that the presence of L-arginine induces nitric oxide synthesis and stimulates capacitation and acrosome reaction of boar spermatozoa only when active sperm anion transport is present as a result of bicarbonate supplementation.

Induction of capacitation and the acrosome reaction of boar spermatozoa by L-arginine and nitric oxide synthesis associated with the anion transport system

The aim of this study was to determine the effect of L-arginine on nitric oxide (NO) synthesis, capacitation and acrosome reaction of boar spermatozoa. Ejaculated boar spermatozoa were washed and then cultured in a bicarbonate:CO(2)-buffered medium, modified NCSU-37, for 2 h. At the end of the culture, the status of spermatozoa was determined. The presence of (0.1-2.0 mmol l(-1)) L-arginine in the culture medium induced an acrosome reaction as determined by fluorescein isothiocyanate-peanut agglutinin (FITC-PNA) and increased intracellular NO content, as quantified by a fluorescent indicator, diaminofluorescein-2 diacetate (DAF-2 DA). This stimulatory effect of L-arginine was neutralized by supplementation with an NO synthase inhibitor, N(omega)-nitro-L-arginine methyl ester (1 mmol l(-1)). However, the inactive enantiomorph, N(omega)-nitro-D-arginine methyl ester, did not affect the stimulatory effect of L-arginine. These results indicate that L-arginine induces an acrosome reaction through the NO signal pathway in boar spermatozoa. Furthermore, the stimulatory effect of L-arginine was inhibited in the presence of an anion transport inhibitor, 4-acetamido-4'-isothiocyano-stilbene-2,2'-disulphonic acid (SITS; 0.1 mmol l(-1)), whereas any responses of spermatozoa to caffeine were not inhibited by SITS. A stimulatory effect of L-arginine on capacitation and acrosome reaction of spermatozoa was also observed in modified NCSU37 medium by using a chlortetracycline fluorescence assay, but not in supplemented bicarbonate-free Tris-buffered medium. These results indicate that the presence of L-arginine induces nitric oxide synthesis and stimulates capacitation and acrosome reaction of boar spermatozoa only when active sperm anion transport is present as a result of bicarbonate supplementation.

Reciprocal synaptic relationships between orexin- and melanin-concentrating hormone-containing neurons in the rat lateral hypothalamus: a novel circuit implicated in feeding regulation

OBJECTIVE

Both orexin (ORX)- and melanin-concentrating hormone (MCH) are expressed in different neurons in the lateral hypothalamic area (LH), and are considered to have common effects on stimulating food intake. There are no reports to demonstrate neural interactions between them at the ultrastructural level. We observed these neurons in the LH to evaluate the relationships between them.

DESIGN

We used two different types of double immunostaining to reveal the ultrastructure of both the ORX- and MCH-containing neurons. A preembedding double immunostaining technique was used to study the synaptic relationships between the two kinds of neuron.

RESULTS

The main new findings are as follows: 1) Both ORX- and MCH-containing neurons received other synaptic input and made synaptic input to other neurons; 2) Reciprocal synaptic relationships were observed between the ORX- and MCH-containing neurons.

CONCLUSION

The ORX- and MCH-containing neurons in the lateral hypothalamic area may influence food intake through synapse with each other.

Endomorphin-2 immunoreactivity in the cervical dorsal horn of the rat spinal cord at the electron microscopic level

Endomorphin-2 is a newly discovered endogenous opioid peptide with high affinity and selectivity for the micro-opioid receptor, and potent analgesic activity, particularly in the spinal cord. Using immunoelectron microscopy, we examined the ultrastructure of the endomorphin-2-like immunoreactive processes and their synaptic relationships in the spinal cord. Endomorphin-2-like immunopositive dense-cored vesicles were observed in many axon terminals, and, in a few cases, were observed together with immunonegative dense-cored vesicles. Immunopositive axons with or without myelination were also observed. The endomorphin-2-like immunoreactive axon terminals formed synapses with both immunopositive and immunonegative processes. Most synapses were asymmetrical, but symmetrical synapses were also found. Examples of axo-dendritic, axo-somatic and axo-axonic contacts were observed. This first demonstration of the ultrastructure and synaptic relationships of endomorphin-2-like immunoreactive axon terminals in the spinal cord dorsal horn provides morphological evidence that this peptide functions as a transmitter regulating pain processes.

[Efficacy of intraperitoneal chemotherapy for advanced Borrmann type IV gastric carcinoma]

We report four patients with advanced Borrmann type IV gastric carcinoma, in whom intraperitoneal chemotherapy with low-dose CDDP and 5-FU plus MMC via a peritoneal port was effective against peritoneal metastasis. However, none of the four patients survived for a long period. During treatment, they were followed on an outpatient basis and received intraperitoneal chemotherapy biweekly with good control of peritoneal metastasis. The ratio of the outpatient follow-up period was more than 50% in all these patients. Intraperitoneal chemotherapy may be effective for controlling peritoneal metastasis of advanced Borrmann type IV gastric carcinoma, and contribute to maintaining the patient's quality of life.

Nuclear transfer of blastomeres expressing EGFP-reporter gene may improve the efficiency of transgenic cattle

The effect of timing of microinjection of DNA constructs on the efficiency of transgenic embryo production and improved efficiency and quality through combining EGFP as a reporter gene with nuclear transfer techniques were examined. From 12 to 24 h after insemination, constructs of pCXNeo-EGFP were microinjected into a pronucleus of bovine IVM-IVF zygotes. Due to the difficulty in visualizing pronuclei, the incidence of successful injection of linear DNA was higher when zygotes were injected between 20 and 24 h, as compared with an early period between 12 and 16 h after insemination. However, developmental competence of DNA-injected zygotes and the EGFP expression rate were not affected by the injection time. A majority of the embryos expressing EGFP signal were mosaic. Following nuclear transfer of blastomeres expressing EGFP, 4.5% of morulae that developed from the NT eggs had a strong EGFP signal in all live blastomeres. In other embryos, EGFP signal had been lost. When cells derived from the EGFP-positive NT morulae were subcultured, all the cells expressed strong EGFP signal at the second passage and demonstrated neomycin resistance. These results show that transient expression of nonintegrated EGFP appears frequently in EGFP-positive bovine embryos and that additional selection of EGFP-positive morulae after nuclear transfer of EGFP-positive blastomeres would facilitate selection of transgenic embryos.

ABCA3 is a lamellar body membrane protein in human lung alveolar type II cells

The ABCA3 gene, of the ABCA subclass of ATP-binding cassette (ABC) transporters, is expressed exclusively in lung. We report here the cloning, molecular characterization, and distribution of human ABCA3 in the lung. Immunoblot analysis using the specific antibody reveals a 150-kDa protein in the crude membrane fraction of human lung. Immunohistochemical analyses of alveoli show that ABCA3 is expressed only in the type II cells expressing surfactant protein A. At the ultrastructural level, ABCA3 immunoreactivity was detected mostly at the limiting membrane of the lamellar bodies. Since members of the ABCA transporter family are known to be involved in transmembrane transport of endogenous lipids, our findings suggest that ABCA3 plays an important role in the formation of pulmonary surfactant in type II cells.

The human homolog of Diminuto/Dwarf1 gene (hDiminuto): a novel ACTH-responsive gene overexpressed in benign cortisol-producing adrenocortical adenomas

To elucidate the molecular mechanism of the pathogenesis of benign functioning adrenocortical adenomas causing Cushing's syndrome, we employed suppression PCR-based cDNA subtractive hybridization to identify novel genes that are differentially expressed in the adenoma. In this report we describe the adenoma-specific overexpression of the human homolog of the Diminuto/Dwarf1 (hDiminuto) gene. Northern blot analysis revealed that hDiminuto mRNA was overexpressed in the adenoma tissue of 14 patients with Cushing's syndrome in comparison to the adjacent nontumorous adrenal gland. In situ hybridization using hDiminuto cRNA probe showed its abundant expression in the tumor cells, whereas the nontumorous cells showed a low level of expression. As the atrophic adjacent gland may not represent the normal architecture, we examined the expression pattern of hDiminuto mRNA in normal human adrenal cortex. In situ hybridization revealed that it was expressed in all layers of the normal adrenal cortex. In situ apoptosis detection by the TUNEL method revealed that a low level of hDiminuto expression in the atrophic, adjacent gland was associated with numerous TUNEL-positive cells in all layers of cortex. In contrast almost no apoptotic cell was detected in the tumor or in the normal adrenal cortex where hDiminuto expression was abundant. These results are compatible with a recent report that hDiminuto acts as an antiapoptotic factor in neurons. The expression of hDiminuto in the normal adrenal cortex was most abundant in the zona fasciculata, suggesting its possible regulation by ACTH/cAMP. Indeed, forskolin treatment of H295R human adrenocortical cells resulted in a significant induction of the mRNA in a time- and dose-dependent manner. To further demonstrate the physiological regulation, an in vivo experiment was carried out in dexamethasone-treated rats. ACTH administration to these rats increased the mRNA expression. These results led us to speculate that the overexpression of hDiminuto in the adenoma could be due to the abundant expression of ACTH receptor, as we previously described. Diminuto is involved in steroid synthesis and cell elongation in plants. We, therefore, hypothesize that hDiminuto might be involved in the molecular events of adrenocortical tumorigenesis by facilitating steroid synthesis and cell growth.

Transmission electron microscopy studies of the zona reaction in pig oocytes fertilized in vivo and in vitro

The aim of this study was to determine the ultrastructure of cross-sectioned zonae pellucidae of in vitro-matured and ovulated pig oocytes before or after sperm penetration in vitro and in vivo, respectively. The in vitro and in vivo (ovulated) oocytes and zygotes (fertilized in vitro and in vivo) were fixed with glutaraldehyde either directly or after pretreatment with ruthenium red and saponin, processed and then examined using transmission electron microscopy. The thickness of the zona pellucida, as measured on the section of the specimens with largest diameter fixed with glutaraldehyde, differed between the in vivo (9.19 +/- 0.47 microm) and in vitro (5.95 +/- 0.51 microm) oocytes. The in vivo oocytes had a rather thick external mesh-like structure, whereas it was much thinner in the in vitro oocytes. This mesh-like external rim was less apparent in both in vivo and in vitro zygotes. Obvious differences in the density of the lattice formed by the fixed zonae pellucidae were visible between the outer and inner (ad-oolemmal) zonae. The outer area always formed a concentrically arrayed fibrillar network, whereas the inner area showed a much more compact, trabecule-like mesh. However, both areas, but particularly the outer network, were much more compacted after the zona reaction. Clear differences in the degree of fibrillar aggregation of the inner zona area were also observed between in vitro and in vivo zygotes, being much higher in the latter. This fibrillar network was more clearly visible in the zygotes pretreated with ruthenium red and saponin; the in vitro zygotes had a fibrillar, radially oriented set of parallel fibrils, whereas it was much more aggregated and trabecule-like in the in vivo zygotes. These results demonstrate that the fine structure of the zona pellucida and the zona reaction at sperm penetration differ between pig oocytes fertilized in vivo and in vitro. Moreover, the ultrastructure of the outer and inner pig zonae pellucidae has a different network organization.

Seaweed prevents breast cancer?

To investigate the chemopreventive effects of seaweed on breast cancer, we have been studying the relationship between iodine and breast cancer. We found earlier that the seaweed, wakame, showed a suppressive effect on the proliferation of DMBA (dimethylbenz(a)anthracene)‐induced rat mammary tumors, possibly via apoptosis induction. In the present study, powdered mekabu was placed in distilled water, and left to stand for 24 h at 4°C. The filtered supernatant was used as mekabu solution. It showed an extremely strong suppressive effect on rat mammary carcinogenesis when used in daily drinking water, without toxicity. In vitro, mekabu solution strongly induced apoptosis in 3 kinds of human breast cancer cells. These effects were stronger than those of a chemothera‐peutic agent widely used to treat human breast cancer. Furthermore, no apoptosis induction was observed in normal human mammary cells. In Japan, mekabu is widely consumed as a safe, inexpensive food. Our results suggest that mekabu has potential for chemoprevention of human breast

Orexin-a activates phospholipase C- and protein kinase C-mediated Ca2+ signaling in dopamine neurons of the ventral tegmental area

The orexin-orexin receptor system has been implicated in the regulation of wakefulness/sleep states. Behavioral and psycho-stimulant effects of orexins have also been shown. Mesolimbic dopamine neurons in the ventral tegmental area (VTA) are implicated in the regulation of reward and wakefulness/sleep, In the present study, we examined the effect of orexin-A on cytosolic [Ca2+]i concentration ([Ca2+]) in the isolated rat VTA dopamine neurons. Orexin-A (10-12-10-8 M) concentration dependently increased [Ca2+]i in dopamine-containing neurons. The [Ca2+]i responses to orexin-A were inhibited under Ca2+-free conditions and by blockers of voltage-gated L- and N-type [Ca2+]i channels, nitrendipine and omega-conotoxin, respectively. The [Ca2+]i responses were also abolished by a phosphatidylcholine-specific phospholipase C inhibitor, D609, and a protein kinase C (PKC) inhibitor, calphostin C. A PKC activator, TPA, mimicked orexin-A in increasing [Ca2+]i. These results indicate that orexin-A increases [Ca2+]i in VTA dopamine neurons via phosphatidylcholine-specific PLC- and PKC-mediated activation of L- and N-type Ca2+ channels. This effect may serve as the mechanism by which orexin regulates wakefulness/sleep states and exerts its behavioral and psychostimulant effects.

Expression of adrenocorticotropin receptor gene in adrenocortical adenomas from patients with Cushing syndrome: possible contribution for the autonomous production of cortisol

OBJECTIVE

To examine whether inhibition of endogenous adrenocorticotropin (ACTH) secretion in patients with Cushing syndrome affects the expression of the ACTH receptor (ACTH-R) gene in adrenocortical adenoma and attached atrophic normal gland.

SUMMARY BACKGROUND DATA

ACTH increases adrenal cell growth and steroidogenesis by means of ACTH-R. In vivo and in vitro studies have shown that expression of ACTH-R is upregulated by its own ligand ACTH in several species. In patients with Cushing syndrome resulting from adrenocortical adenoma, there is autonomous production of cortisol from the adenoma. This strongly inhibits endogenous ACTH secretion, giving rise to the speculation that the expression of the ACTH-R gene in these patients is also suppressed. However, previous studies have shown that administration of exogenous ACTH to these patients leads to a further increase in the production of cortisol, suggesting the expression of functional ACTH-R in the adenoma. The authors, therefore, examined the expression of the ACTH-R gene in these patients.

METHODS

Fourteen patients with Cushing syndrome were studied. Glucocorticoid excess resulting from autonomous production from the adenomas was ascertained, and unilateral adrenalectomy was performed. The levels of ACTH-R and cytochrome P450 side chain cleavage enzyme (P450scc) mRNAs were determined by Northern blot analysis. The entire coding region of the ACTH-R gene in these patients was sequenced.

RESULTS

ACTH-R mRNA abundance in the attached atrophic normal adrenals was suppressed and invariably less than that in the normal gland obtained from a patient with renal cancer. However, the expression of ACTH-R mRNA was not suppressed in any of the adenomas. Expression of ACTH-R mRNA in the adenomas was four- to sixfold greater than that in the attached atrophic gland. No mutation in the coding sequence of the ACTH-R gene in the adenoma was detected in any of the patients. The mRNA in the adenomas appeared to be translated into functionally active receptor because intramuscular administration of ACTH resulted in significant increases in plasma cortisol before surgery but not 3 months after surgery. In addition, there was a positive linear correlation between the expressions of ACTH-R and P450scc mRNAs in the adenoma tissue.

CONCLUSIONS

Suppressed ACTH secretion in patients with Cushing syndrome results in reduction of the ACTH-R mRNA expression in nonneoplastic adrenocortical cells. However, the regulatory mechanism of ACTH-R expression might be different in adenoma. Persistent expression in the adenoma of ACTH-R alone, even in the absence of ACTH, might result in increased basal adenyl cyclase activity, as observed in the case of thyroid-stimulating hormone receptor, and thereby might play a role in the autonomous production of cortisol.

Observation of rho/omega meson modification in nuclear matter

We measured the invariant mass spectra of electron-positron pairs in the target rapidity region of 12-GeV p+A reactions. We have observed a significant difference in the mass spectra below the omega meson between p+C and p+Cu interactions. This difference indicates that the spectral shape of mesons is modified at normal nuclear-matter density.

Regulation of serotonin transporter gene expression in human glial cells by growth factors

The aims of this study were to identify monoamine transporters expressed in human glial cells, and to examine the regulation of their expression by stress-related growth factors. The expression of serotonin transporter mRNA was detected by reverse transcriptase-polymerase chain reaction in normal human astrocytes, whereas the dopamine transporter (DAT) and the norepinephrine transporter (NET) were not detected. The cDNA sequence of the "glial" serotonin transporter in astrocytes was consistent with that reported for the "neuronal" serotonin transporter (SERT). Moreover, we also demonstrated SERT expression in glial fibrillary acidic protein-positive cells by immunocytochemical staining in normal human astrocytes. Serotonin transporter gene expression was also detected in glioma-derived cell lines (A172, KG-1-C and KGK). Addition of basic fibroblast growth factor (bFGF) or epidermal growth factor (EGF) for 2 days increased serotonin transporter gene expression in astrocytes and JAR (human choriocarcinoma cell line). Basic fibroblast growth factor, but not epidermal growth factor, increased specific [3H]serotonin uptake in astrocytes in a time (1-4 days)- and concentration (20-100 ng/ml)-dependent manner. The expression of genes for basic fibroblast growth factor and epidermal growth factor receptors was detected in astrocytes. These findings suggest that the expression of the serotonin transporter in human glial cells is positively regulated by basic fibroblast growth factor.

Role of ultrasonography in the detection of intraductal spread of breast cancer: correlation with pathologic findings, mammography and MR imaging

The purpose of this study was to assess the role of US in the detection of intraductal spread of breast cancer in comparison with mammography (MMG) and MRI. In 46 patients with breast cancer, US features of the intraductal component were classified as ductal type or distorted type. Histopathologically, 29 of 46 (63%) cases had intraductal components, and the sensitivity, specificity, and accuracy rates in detection of intraductal spread were 89, 76, and 85%, respectively. Each US pattern demonstrated good correspondence to the histologic components, and the distorted type correlated well with comedo-type carcinoma. Mammography was performed in all cases, and the sensitivity, specificity, and accuracy rates in detection of intraductal spread were 55, 100, and 72%, respectively. In comedo type, MMG could diagnose the extent of intraductal spread more accurately compared with US examination. Magnetic resonance imaging comparison was available in 25 cases. Magnetic resonance imaging depicted intraductal extension as an enhanced area during the early phase of a contrast enhancement study with a sensitivity of 93%. Ultrasound and MRI were closely related in terms of morphologic characteristics: the ductal type of US image correlated well with linear enhancement on MRI, whereas the distorted type correlated with regional or segmental enhancement. Current US examination is useful in depicting the intraductal spread of breast cancer; however, US has a tendency to underestimate intraductal component of comedo type compared with MMG and MRI.

Overexpression of glutathione-S-transferase A1 in benign adrenocortical adenomas from patients with Cushing's syndrome

Benign adrenocortical adenoma is a major primary cause of Cushing's syndrome. Although numerous studies have been performed, the molecular mechanism of adrenocortical adenoma is yet to be elucidated. In this study we endeavored to identify genes differentially regulated in adrenocortical adenoma by suppression PCR-based complementary DNA (cDNA) subtractive hybridization. The cDNA population in atrophied nontumorous adrenal gland adjacent to the adenoma was subtracted from that in the adenoma. Then adenoma-specific cDNAs were amplified by PCR. We cloned several cDNAs that are selectively up-regulated in the adenoma, one of which was identified to encode glutathione-S-transferase A1 (GSTA1). Northern blot analysis revealed that GSTA1 messenger ribonucleic acid was abundantly expressed in the adenoma compared with that in the adjacent atrophied nontumorous gland. Western blot analysis and immunohistochemistry showed high expression of GSTA1 also at the protein level. In concordance with this finding, GST activity was significantly higher in the adenoma than in the adjacent atrophied nontumorous gland. To clarify the role of GSTA1 in adrenocortical cells, GST activity in the H295R human adrenocortical cell line was inhibited by ethacrynic acid. Inhibition of GSTs interfered with proliferation of the cells. We, therefore, hypothesize that overexpression of GSTA1 in adrenocortical adenomas might be involved in the growth of tumor cells. We also speculate that this overexpression might be an adaptive response to excess cortisol production.

Regulation of in vitro penetration of frozen-thawed boar spermatozoa by caffeine and adenosine

Effects of caffeine and adenosine on the function and in vitro penetration of frozen-thawed boar spermatozoa were examined. First, the effect on sperm function was determined by the chlortetracycline fluorescence assessment. Both caffeine and adenosine stimulated capacitation of spermatozoa. However, adenosine, but not caffeine, inhibited spontaneous acrosome loss. Second, sperm penetration into in vitro matured oocytes was compared among spermatozoa cultured in the absence or presence of caffeine or adenosine. Both caffeine and adenosine increased the penetration rate (99.1 +/- 0.9% in caffeine, 72.4 +/- 2.0% in adenosine vs. 54.8 +/- 5.1% in controls) but only caffeine decreased drastically the monospermic penetration rate (8.0 +/- 2.3% in caffeine vs. 75.4 +/- 4.8% in adenosine and 78.6 +/- 4.8% in controls). When oocytes were cocultured in various sperm concentrations, the proportion of monospermy changed in inverse proportion to sperm concentration in the presence of caffeine, but did not change in the presence of adenosine. A relatively high number of spermatozoa at the early stage of spontaneous acrosome reaction in the presence of caffeine may be one of the main causes of polyspermic penetration in porcine IVF system. These results indicate that replacement of caffeine with adenosine in fertilization medium improves monospermic penetration by frozen-thawed boar spermatozoa.

Somatic gene alteration of AIB1 gene in patients with breast cancer

AIB1 (amplified in breast cancer 1) is a coactivator which stimulates the transcriptional activity of the liganded-estrogen receptor (ER). It has been reported that AIBI gene is amplified and overexpressed in some breast cancer cell lines. AIB1 contains a stretch of homopolymeric glutamines (poly-Q). We reported that the poly-Q shows polymorphism, which provides an opportunity to study somatic gene alteration such as loss of heterozygosity (LOH). In the present study, we aimed to investigate the frequency of somatic gene alteration in Japanese patients with breast cancer. Amplification of AIB1 gene was detected only in 1 (2.6%) of 39 breast cancer tissues by DNA dot blot analysis. On the other hand, LOH was found in 2 (8%) breast cancer tissues out of 25 patients showing heterozygosity in peripheral blood mononuclear cells (PBMC). Taken together, both LOH and amplification of AIB1 gene were identified in breast cancer patients, raising the possibility that AIB1 have oncogenic as well as antioncogenic potential for the pathogenesis of breast cancer.

Thyrotropin modifies activation of nuclear factor kappaB by tumour necrosis factor alpha in rat thyroid cell line

We have recently demonstrated that nuclear factor kappaB (NF-kappaB) mediates the tumour necrosis factor alpha (TNF-alpha)-dependent expression of the gene encoding interleukin 6 (IL-6) in rat thyroid FRTL-5 cells cultured in the presence of thyrotropin (TSH). In the present study we investigated how TSH is involved in the activation of NF-kappaB by TNF-alpha in the cells. Electrophoretic mobility-shift assay revealed that, in the absence of TSH, TNF-alpha activated a single protein-DNA complex containing the p50 subunit but not other NF-kappaB subunits such as p65. In contrast, two distinct protein-DNA complexes were activated in the presence of TSH: the faster-migrating complex contained only p50 subunit; the slower-migrating complex consisted of p65-p50 heterodimer. This TSH effect was mimicked by forskolin and thyroid-stimulating antibodies obtained from patients with Graves's disease, suggesting that an increase in intracellular cAMP is responsible for the induction of different NF-kappaBs by TNF-alpha. A transient transfection study with a luciferase reporter gene driven by multimerized NF-kappaB sites demonstrated that TNF-alpha increased the luciferase activities only in the presence of TSH, and that this increase was inhibited by the co-transfection of mutant p65, which prevented the function of wild-type p65 in a dominant-negative manner. Accordingly, TNF-alpha activated the expression of the IL-6 gene in the presence of TSH but not in its absence. Although the expression of the p105 gene, another known target for NF-kappaB, was increased by TNF-alpha in the absence of TSH, the presence of TSH further increased the mRNA level. Taken together, these observations indicate that the presence of TSH is crucial for the NF-kappaB-mediated actions of TNF-alpha on thyroid follicular cells.

Orexinergic innervation of POMC-containing neurons in the rat arcuate nucleus

A pre-embedding double immunostaining technique was used to study the synaptic relationships between orexin-like immunoreactive axon terminals and preopiomelanocortin (POMC)-like immunoreactive neurons in the rat arcuate nucleus. Most of the synapses were axo-dendritic, while some axo-somatic synapses were also found. Both the axo-somatic and axodendritic synapses were symmetrical. In some cases the presynaptic orexin-like immunoreactive axon terminals contained a few large dense-cored vesicles. The results suggest that the orexinergic axon terminals in the arcuate nucleus may play an important role in the regulation of food intake via synapses through POMC neurons.

Functional significance of colocalization of PACAP and catecholamine in nerve terminals

Medullary neurons containing pituitary adenylate cyclase-activating polypeptide (PACAP) and noradrenalin (NA) project to the hypothalamus and they are involved in the regulation of arginine vasopressin (AVP) neurons. At the ultrastructural level, PACAP immunoreactivity was detected in the granular vesicles in catecholaminergic nerve terminals that made synaptic contact with AVP neurons. Both PACAP (at least 1 nM) and NA (at least 1 microM) induced large increases in the cytosolic Ca2+ concentration ([Ca2+]i) in isolated AVP cells. PACAP at 0.1 nM and NA at 0.1 microM had little effects, if any, on [Ca2+]i. However, when 0.1 nM PACAP and 0.1 microM NA were combined, they evoked large increase in [Ca2+]i in AVP neurons. An inhibitor of protein kinase A (PKA) completely inhibited the PACAP-induced increase in [Ca2+]i, but only partly inhibited the NA-induced increase in [Ca2+]i. In AVP cells that were prelabeled with quinacrine, PACAP and NA acted synergistically to induce a loss of quinacrine fluorescence, indicating secretion of neurosecretory granules in AVP neurons. The results suggest that PACAP and NA, coreleased from the same nerve terminals, act in synergy to evoke calcium signaling and secretion in AVP neurons, and that the synergism is mediated by the interaction between cAMP-PKA pathway an as yet unidentified factor "X" linked to L-type Ca2+ channels. The synergism between PACAP and NA may contribute to the regulation of AVP secretion under physiological conditions.