Histone deacetylases induce angiogenesis by negative regulation of tumor suppressor genes

Low oxygen tension influences tumor progression by enhancing angiogenesis; and histone deacetylases (HDAC) are implicated in alteration of chromatin assembly and tumorigenesis. Here we show induction of HDAC under hypoxia and elucidate a role for HDAC in the regulation of hypoxia-induced angiogenesis. Overexpressed wild-type HDAC1 downregulated expression of p53 and von Hippel-Lindau tumor suppressor genes and stimulated angiogenesis of human endothelial cells. A specific HDAC inhibitor, trichostatin A (TSA), upregulated p53 and von Hippel-Lindau expression and downregulated hypoxia-inducible factor-1alpha and vascular endothelial growth factor. TSA also blocked angiogenesis in vitro and in vivo. TSA specifically inhibited hypoxia-induced angiogenesis in the Lewis lung carcinoma model. These results indicate that hypoxia enhances HDAC function and that HDAC is closely involved in angiogenesis through suppression of hypoxia-responsive tumor suppressor genes.

Capsaicin inhibits the voltage-operated calcium channels intracellularly in the antral circular myocytes of guinea-pig stomach

Studies of the effect of capsaicin (CAP) on the smooth muscle contractions have shown both contraction and relaxation in various preparations. The direct effect of CAP on gastric smooth muscle itself has not yet been reported, though CAP was reported to relax the isolated guinea-pig stomach by releasing nitric oxide from the CAP-sensitive sensory neurons. Here we showed an evidence that CAP evokes a prolonged relaxation of gastric antral circular smooth muscle (CAP-induced relaxation) by blocking the voltage-operated Ca2+ channels (VOCC) from inside of the cell. CAP suppressed dose-dependently the spontaneous contractions of guinea-pig gastric circular muscle strip under the condition without neural influence (IC50 = 5.8 microM). The inhibitory effects of CAP both on the high K+ contracture induced by 50 mM K+ Tyrode solution and on the slow waves recorded using a conventional intracellular microelectrode technique were similar to those of Ca2+ channel antagonists, indicating that Ca2+ influx through the VOCC is decreased by CAP. Ca2+ channel current (I(Ba)) decreased in a concentration-dependent manner on superfusing the physiological salt solution containing various concentrations of CAP. The steady-state activation and inactivation curves of I(Ba) were not affected by the treatment with CAP. The experiment using a synthetic water-soluble analog of CAP, DA-5018 x HCl, suggested that the acting site of CAP is present in the intracellular side. Spontaneous transient outward K+ currents (STOCs) recorded at a holding potential of 0 mV were also inhibited by CAP and verapamil, Ca channel blocker. Taken together, these results indicate that CAP-induced relaxation is associated with the direct inhibitory action on the VOCC from inside of the cell.

Complex bronchopulmonary foregut malformation: extralobar pulmonary sequestration associated with a duplication cyst of mixed bronchogenic and oesophageal type

We report a 13-year-old girl with an unusual, complex bronchopulmonary foregut malformation. The malformation included extralobar pulmonary sequestration and a duplication cyst of mixed bronchogenic and oesophageal type. Preoperative CT and MRI demonstrated the cystic and solid portions of the mass and indicated an aberrant vascular supply, suggesting the possibility of bronchopulmonary foregut malformation and several other differential diagnoses. A direct communication between the cyst and the bronchus of the sequestrated lung was found on pathological examination. This unusual combination of an extralobar pulmonary sequestration and a foregut cyst points to a common embryological pathogenesis.

Expression of Fas ligand and apoptosis of disc cells in herniated lumbar disc tissue

STUDY DESIGN

An examination of surgically obtained herniated lumbar disc tissues performed by using immunohistochemical staining and the DNA nick end labeling method.

OBJECTIVE

To investigate the cell type that expresses Fas ligand (FasL) and any evidence of apoptosis of the disc cells in herniated lumbar disc tissues.

SUMMARY OF BACKGROUND DATA

The Fas/FasL system is involved in delivering a death signal that rapidly commits the cells to apoptosis. In the authors' previous study, the expression of Fas on disc cells was identified in herniated lumbar disc tissue.

METHODS

Twenty-three herniated lumbar disc tissues (contained disc, n = 9; noncontained disc, n = 14) were examined to investigate the cell type that expresses FasL and any evidence of apoptosis of the disc cells by using immunohistochemical staining and the DNA nick end labeling method, respectively. The percentage of FasL-positive disc cells was calculated and compared with clinical and radiologic data.

RESULTS

FasL was expressed in the cytoplasm of the disc cells, and nuclear DNA fragmentation in a few disc cells was identified. A higher degree of FasL expression in disc cells was found in noncontained discs than in contained discs (P < 0.05). The percentage of FasL-positive disc cells significantly increased with the patient's age (P < 0.05), but not with the degree of disc degeneration (P > 0.05).

CONCLUSION

The current results indicate that disc cells, after herniation, undergo apoptotic cell death via autocrine or paracrine FasL mechanisms by the disc cells themselves.

Facet tropism: a comparison between far lateral and posterolateral lumbar disc herniations

STUDY DESIGN

An assessment of the difference in the degree of facet tropism and disc degeneration between far lateral and posterolateral lumbar disc herniations.

OBJECTIVE

To investigate the effect of the difference in the degree of the facet tropism and disc degeneration with respect to the development of far lateral lumbar disc herniation and posterolateral lumbar disc herniation, and to compare the effect between the two types of herniations.

SUMMARY OF BACKGROUND DATA

The effect of facet tropism on the development of posterolateral lumbar disc herniation has been investigated previously, but there has been no study on far lateral lumbar disc herniation.

METHODS

Thirty-eight lumbar disc herniations (far lateral, n = 19; posterolateral, n = 19) were included this study. The degree of facet tropism and disc degeneration was measured at the herniated disc level by using magnetic resonance imaging. The results were compared to show any differences between the two types of lumbar disc herniations.

RESULTS

There were significant differences in the degree of facet tropism (24.74 vs. 14.26, P = 0.004) and disc degeneration (23.92 vs. 15.08, P = 0.005) between the far lateral and posterolateral lumbar disc herniations. There was no significant correlation between the degree of facet tropism and the degree of disc degeneration in far lateral lumbar disc herniation (r = -0.369, P = 0.120).

CONCLUSION

This results suggest that the differences in the degree of facet tropism and disc degeneration might be considered a key factor in distinguishing the development of far lateral lumbar disc herniation from that of posterolateral lumbar disc herniation.

No association between presenilin 1 (PS1) intronic polymorphism and sporadic Alzheimer's disease in Koreans

To investigate the possible involvement of an intronic polymorphism in the presenilin 1 (PS1) gene and its interactions with the aplolipoprotein E (APOE) or alpha-1 antichymotrypsin (ACT) polymorphisms in the manifestation of AD, we analyzed the PS1, APOE and ACT genotypes of 100 sporadic AD patients and 199 normal elderly controls in Koreans. The genotypic (chi2= 0.92, df = 2, P > 0.1) and allelic (chi2 = 0.01, df = 1, P > 0.1) frequencies of the PS1 polymorphism in the late- and early-onset sporadic AD patients did not differ from those in the controls. And the occurrence of the APOE epsilon4 allele and ACT A allele did not influence the distribution of the PS1 intronic polymorphism. The PS1 intronic polymorphism didn't influence the age-at-onset of AD (F = 0.02, df = 2, P > 0.1). In conclusion, the PS1 intronic polymorphism did not modify the risk for sporadic AD, neither independently nor synergistically with the APOE epsilon4 allele or ACT A allele, in Koreans.

Anti-invasive activity of torilin, a sesquiterpene compound isolated from Torilis japonica

Torilin is a sesquiterpene compound purified from Torilis japonica (Umbelliferae). We have previously reported that torilin has a potent anti-angiogenic activity both in vivo and in vitro. In the present study, we investigated the anti-invasive activity of torilin, and interestingly found that torilin completely blocked intravasation of HT1080 human fibrosarcoma cells inoculated on the chorioallantoic membrane (CAM) of chick embryo. In addition, torilin decreased the attachment of HT1080 cells to confluent human umbilical vein endothelial cells (HUVECs) at non-toxic concentration. In in vitro transwell invasion model, 25 microM torilin also significantly inhibited HT1080 cell invasion in a time-dependent manner. Activity and expression of matrix metalloproteinase-9 (MMP-9) that is very important in tumor invasion and metastasis were also decreased by torilin treatment, indicating that the inhibitory effect of torilin on invasion of HT1080 cells may result from decreasing activity and expression of MMP-9. Therefore, it is possible that torilin may decrease metastatic potential of tumor cells through inhibiting their attachment to endothelial cells and intravasation to blood vessels. Taken together, torilin may have a strong activity to suppress tumorigenesis by inhibition of tumor invasion.

Peripheral T-cell lymphoma of the colon: double-contrast barium enema examination findings in six patients

PURPOSE

To evaluate radiologic findings of peripheral T-cell lymphoma (PTCL) of the colon at double-contrast barium enema examination.

MATERIALS AND METHODS

Double-contrast barium enema findings in six patients with pathologically proved PTCL of the colon were retrospectively evaluated and compared with colonoscopic and histopathologic findings.

RESULTS

There was a diffuse involvement of almost all segments of the colon in four patients and a focal segmental involvement in two. Frequent findings at double-contrast barium enema examination included geographic ulcerations (n = 6), aphthous ulcerations (n = 4), pseudopolyps (n = 4), circumferential luminal narrowing (n = 4), and ileocecal deformity (n = 4).

CONCLUSION

PTCL of the colon manifested as either a diffuse or a focal segmental lesion and showed extensive mucosal ulceration at double-contrast barium enema examination. These findings are similar to those of inflammatory bowel disease and are different from those of colorectal lymphoma with the B-cell phenotype.

Human rad21 gene, hHR21(SP), is downregulated by hypoxia in human tumor cells

To identify genes differentially expressed under normoxic (21% O(2)) or hypoxic (1% O(2)) conditions, we used the technique of mRNA differential display using total RNA extracted from Chang human liver cells. Among downregulated genes by hypoxia, we focused on hHR21(SP) (human homologue of rad21 S. pombe) that is involved in DNA double-strand break repair. Northern blot analysis revealed that mRNA expression of hHR21(SP) was inhibited by hypoxia in various tumor cell lines, such as HepG2, SKHep1, MCF7, and HT1080 cells. We also found that hypoglycemia and heat shock significantly decreased the hHR21(SP) level, indicating that a DNA double-strand break repair gene, hHR21(SP) might be regulated by environmental stresses. In addition, wortmannin, a DNA-dependent protein kinase (DNA-PK) inhibitor, decreased the level of hHR21(SP) mRNA, indicating that DNA-PK might be involved in the regulation of hHR21(SP). These results propose a new understanding of hHR21(SP) regulations in human tumor cells.

Urachal remnant diseases: spectrum of CT and US findings

Computed tomography (CT) and ultrasonography (US) are ideally suited for demonstrating urachal remnant diseases. A patent urachus is demonstrated at longitudinal US and occasionally at CT as a tubular connection between the anterosuperior aspect of the bladder and the umbilicus. An umbilical-urachal sinus manifests at US as a thickened tubular structure along the midline below the umbilicus. A vesicourachal diverticulum is usually discovered incidentally at axial CT, appearing as a midline cystic lesion just above the anterosuperior aspect of the bladder. At US, it manifests as an extraluminally protruding, fluid-filled sac that does not communicate with the umbilicus. Urachal cysts manifest at both modalities as a noncommunicating, fluid-filled cavity in the midline lower abdominal wall located just beneath the umbilicus or above the bladder. Both infected urachal cysts and urachal carcinomas commonly display increased echogenicity at US and thick-walled cystic or mixed attenuation at CT, making it difficult to differentiate between them. Percutaneous needle biopsy or fluid aspiration is usually needed for diagnosis and therapeutic planning. Nevertheless, CT and US can help identify most disease entities originating from the urachal remnant in the anterior abdominal wall. Understanding the anatomy and the imaging features of urachal remnant diseases is essential for correct diagnosis and proper management.

A sesquiterpene lactone, costunolide, from Magnolia grandiflora inhibits NF-kappa B by targeting I kappa B phosphorylation

A sesquiterpene lactone, costunolide (CTN), was identified from Magnolia grandiflora together with parthenolide (PTN) by its strong inhibition of LPS-induced NF-kappa B activation. CTN, which showed more potent inhibition than PTN in the NF-kappa B activation, strongly suppressed nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells. RT-PCR and Western blot analyses demonstrated that CTN suppressed the expression of iNOS mRNA and protein in a dose-dependent manner. CTN also significantly inhibited LPS-induced DNA-binding activity of NF-kappa B as well as the LPS-induced degradation of I kappa B-alpha and -beta. Furthermore, CTN inhibited LPS-induced phosphorylation of I kappa B-alpha. These findings support that CTN inhibits NO production by down-regulating iNOS expression, at least, in part through the inhibition of I kappa Bs' phosphorylation and degradation, which are essential for the activation of NF-kappa B.

The effects of dexamethasone on insulin release and biosynthesis are dependent on the dose and duration of treatment

Complex results concerning the effect of glucocorticoids on insulin secretion have been reported. The aim of this study is to clarify the direct effects of glucocorticoids on pancreatic islets and to determine whether the effect of glucocorticoids on insulin biosynthesis or release is dependent on the dose and duration of treatment with glucocorticoid. Studies on insulin secretion and biosynthesis were performed with different concentrations (0, 1, 10, 100 nmol/l) and durations (1 and 6 h) of treatment with dexamethasone (dexa) in rat pancreatic islets. (1) One nmol/l dexa had no inhibitory effect on insulin secretion and biosynthesis. Ten and 100 nmol/l had an inhibitory effect on insulin secretion, which was mainly due to suppression of the first phase of insulin secretion. (2) Insulin content was significantly increased regardless of the concentration in 1-h treated islets. However, insulin content was markedly diminished with 100 nmol/l dexa in 6-h treated islets. (3) The preproinsulin mRNA expression of 6-h treated islets was suppressed in a dose-dependent manner. Our data revealed that, in the condition of short-term and low-dose glucocorticoid exposure, insulin secretion and biosynthesis are not affected. The secretory process of insulin seems to be the initial step of the inhibitory action of glucocorticoid. Both insulin release and biosynthesis are inhibited by chronic exposure to high dose dexamethasone. It can be concluded that glucocorticoid might be involved in the multisteps of insulin release and biosynthesis.

The properties of carbachol-activated nonselective cation channels at the single channel level in guinea pig gastric myocytes

We investigated the properties of carbachol (CCh)-activated nonselective cation channels (NSC(CCh)) at the single channel level in the gastric myocytes of guinea pigs using a magnified whole-cell mode or an outside-out mode. The channel activity (NPo) recorded in a magnified whole-cell mode increased with depolarization (from -120 to -20 mV) and had the half activation potential of -81 mV under the symmetrical 140 mM Cs+ condition. The single channel conductance depended upon the extracellular monovalent cations with the order of Cs+ (35 pS) > Na+ (25 pS) > Li+ (21 pS). The channel activities markedly diminished or disappeared when external Cs+ was replaced with Na+ or N-methyl-D-glucamate (NMDG+). With Cs+ and Na+ as external cations, the channel showed a monotonic increase in NPo with the increased mole fraction of Cs+ over Na+, and it had an intermediate conductance value in solution containing 67% Cs+ with 33% Na+. These data suggested that the extracellular monovalent cations regulate the whole-cell current of NSC(CCh) by modulating both the open state probability and the unitary conductance, and there is one binding site for the extracellular cations within the pore.

Systemic arterial supply to the lungs in adults: spiral CT findings

Systemic arterial supply to the lungs can be congenital or due to acquired disease. Congenital diseases encompass bronchopulmonary sequestration and congenital pulmonary venolobar syndrome, in which the involved lung parenchyma is supplied by the aberrant systemic arteries. An anomalous systemic artery can also supply an area of otherwise normal lung parenchyma. In acquired diseases, hypertrophied normal systemic arteries supply the lungs. Hypertrophied systemic arteries include the bronchial arteries, intercostal arteries, internal mammary arteries, inferior phrenic arteries, branches of the thyrocervical trunk, branches of the hepatic arteries, and branches of the abdominal aorta. Hypertrophy of normal systemic arteries is encountered in patients with bronchiectasis, pulmonary tuberculosis, other pulmonary infections, pulmonary thromboembolism, or chronic obstructive pulmonary disease. These systemic arteries are considered to supply the lungs by means of anastomoses between bronchial and pulmonary arteries within the lung parenchyma or transpleural systemic-pulmonary artery anastomoses. In most cases, the correct diagnosis and treatment plan can be determined by identification of the systemic arteries on computed tomographic scans.

Ligand binding profiles of delta-opioid receptor in human cerebral cortex membranes: evidence of delta-opioid receptor heterogeneity

In this study, receptor binding profiles of opioid ligands for subtypes of opioid delta-receptors were examined employing [3H]D-Pen2,D-Pen5-enkephalin ([3H]DPDPE) and [3H]Ile(5,6)-deltorphin II ([3H]Ile-Delt II) in human cerebral cortex membranes. [3H]DPDPE, a representative ligand for delta1 sites, labeled a single population of binding sites with apparent affinity constant (Kd) of 2.72 +/- 0.21 nM and maximal binding capacity (Bmax) value of 20.78 +/- 3.13 fmol/mg protein. Homologous competition curve of [3H]Ile-Delt II, a representative ligand for delta2 sites, was best fit by the one-site model (Kd = 0.82 +/- 0.07 nM). Bmax value (43.65 +/- 2.41 fmol/mg) for [3H]Ile-Delt II was significantly greater than that for [3H]DPDPE. DPDPE, [D-Ala2,D-Leu5]enkephalin (DADLE) and 7-benzylidenaltrexone (BNTX) were more potent in competing for the binding sites of [3H]DPDPE than for those of [3H]Ile-Delt II. On the other hand, deltorphin II (Delt II), [D-Ser2,Leu5,Thr6]enkephalin (DSLET), naltriben (NTB) and naltrindole (NTI) were found to be equipotent in competing for [3H]DPDPE and [3H]Ile-Delt II binding sites. These results indicate that both subtypes of opioid delta-receptors, delta1 and delta2, exist in human cerebral cortex with different ligand binding profiles.

Association of alpha-2-macroglobulin deletion polymorphism with sporadic Alzheimer's disease in Koreans

Alpha-2-macroglobulin (A2M) deletion polymorphism was recently reported to be associated with Alzheimer's disease (AD) in a way comparable to apolipoprotein E (APOE) polymorphism in a family-based study. However, the association of A2M deletion polymorphism with AD has not been consistently replicated in successive case-controlled studies. In order to evaluate whether this A2M polymorphism is associated with AD in Koreans, we examined the frequencies of the A2M deletion (D) allele and D-bearing genotypes in a group of Koreans composed of 100 sporadic AD patients and 203 control subjects. The frequency of the deletion (D) allele (P=0.046) was significantly different between the total group of AD patients and the controls, although the frequency of the D-bearing genotypes did not attain significance (P=0.078). When the subjects were stratified according to age at onset, there was significant difference in the frequencies of the D allele (P=0.044) and D-bearing genotypes (P=0.041) between late-onset AD patients (> or =65 years) and the controls. However, no significant difference was observed between early-onset AD patients (<65 years) and the control group. Additionally, when we divided the late-onset AD and control subjects by APOE epsilon4 status, the difference of the A2M D allelic frequency was significant only in the APOE epsilon4 negative subjects (P=0.015). In conclusion, our data suggests that the A2M D allele is a modest risk factor for late-onset sporadic AD in Koreans, and the AD risk conferred by the A2M D allele increases in APOE epsilon4 negative subjects.

Novel bile acid derivatives induce apoptosis via a p53-independent pathway in human breast carcinoma cells

We have compared the anti-proliferative effects of ursodeoxycholic acid (UDCA), chenodeoxycholic acid (CDCA) and their derivatives, HS-1183, HS-1199 and HS-1200, on MCF-7 (wild-type p53) and MDA-MB-231 (mutant p53) cells. While UDCA and CDCA exhibited no significant effect, their novel derivatives inhibited the proliferation of both cell lines in a concentration-dependent manner, concomitant with apoptotic nuclear changes and the increase of a sub-G1 population and DNA fragmentation. Furthermore, we also observed an increase in the ratio of pro-apoptotic protein Bax to anti-apoptotic protein Bcl-2 and cleavages of lamin B and poly(ADP-ribose) polymerase (PARP) in MCF-7 and MDA-MB-231 cells. Cell cycle related proteins, cyclin D1 and D3, as well as retinoblastoma protein (pRb) were down-regulated, while the level of cyclin-dependent kinase inhibitor p21(WAF1/CIP1) was increased in both cancer cells after treatment with novel bile acids. These findings suggest that these cytotoxic effects of novel bile acid derivatives on human breast carcinoma cells were mediated via apoptosis through a p53-independent pathway.

Pharmacological effects of naltriben as a ligand for opioid mu and kappa receptors in rat cerebral cortex

Naltriben (NTB) has been used to differentiate the subtypes of delta opioid receptors, delta1 and delta2. However, there is considerable evidence suggesting that NTB may act on other types of opioid receptors too. We examined the effects of NTB on the specific binding of radiolabeled ligands for opioid mu and kappa2 receptors, and the effects on the release of [3H]norepinephrine ([3H]NE) in rat cerebral cortex slices. NTB displaced the specific binding of [3H]DAMGO with Ki value of 19.79 +/- 1.12 nM in rat cortex membranes. Specific binding of [3H]diprenorphine ([3H]DIP) was inhibited by NTB with Ki value of 82.75 +/- 6.32 nM in the presence of DAMGO and DPDPE. High K+ (15 mM)-stimulated release of [3H]NE was attenuated by DAMGO in rat cerebral cortex slices. NTB (30 nM) shifted the dose-response curve of DAMGO to the right and attenuated the maximal effect. In the meantime, NTB inhibited high K+-stimulated [3H]NE release at concentrations above 100 nM. The inhibitory effect of NTB was not attenuated by CTAP (10 nM) and naloxone (3 nM) but by higher concentration of naloxone (30 nM), nor-BNI (300 nM) and bremazocine (3 nM). These results indicate that NTB, depending on the dosage, could acts not only as an antagonist at delta but also as a noncompetitive antagonist for mu receptors, and as an agonist for kappa2 receptors in rat cerebral cortex.

Determination of hypoxic region by hypoxia marker in developing mouse embryos in vivo: a possible signal for vessel development

Hypoxia is a well-known signal for angiogenesis, but the recent proposal that hypoxia exists in developing embryonic tissues and that it induces vascular development remains to be proven. In the present study, we demonstrate the presence of hypoxia in normal developing embryos by means of a hypoxia marker, pimonidazole, and its associated antibody. Our data clearly show that hypoxia marker immunoreactivity was highly detected in developing neural tubes, heart, and intersomitic mesenchyme at an early stage of organogenesis, suggesting that hypoxia may exist in the early stages of embryo development. We also found that hypoxia inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) were spatiotemporally co-localized with possible hypoxic regions in embryos. Investigation of platelet endothelial cell adhesion molecule (PECAM) expression provides evidence that endothelial cells proliferate and form the vessels in the hypoxic region in developing organs. Furthermore, we found that hypoxia induced both HIF-1alpha and VEGF in F9 embryonic stem and differentiated cells. Thus, we suggest that hypoxia may exist widely in developing embryonic tissues and that it may act as a signal for embryonic blood vessel formation in vivo.

Latency- and Defense-Related Ultrastructural Characteristics of Apple Fruit Tissues Infected with Botryosphaeria dothidea

ABSTRACT Apple fruit tissues infected with Botryosphaeria dothidea were examined by transmission electron microscopy using susceptible cv. Fuji and resistant cv. Jonathan. Immature (green) and mature (red) fruits of cv. Fuji with restricted or expanding lesions were also examined to reveal subcellular characteristics related with latent and restricted disease development. In infected susceptible mature fruits, cytoplasmic degeneration and organelle disruption commonly occurred, accompanying cell wall dissolution around invading hyphae. Cell wall dissolution around invading hyphae in subepidermis was rare in immature, red halo-symptomed cv. Fuji and resistant cv. Jonathan fruits. In infected immature fruits of cv. Fuji, presumably at the latent state of disease development, cellular degeneration was less severe, and invading hyphae contained prominent microbody-lipid globule complexes or the deposition of thin electron-dense outer layer around cell wall of intercellular hyphae. Both mature fruits with red halos and resistant apple fruits formed cell wall protuberances at the outside of cell walls. In addition, electron-dense extramural layers were formed in the resistant apple fruits. Aberrant hyphal structures such as intrahyphal hyphae were found only in resistant fruit tissues, indicating the physiologically altered fungal growth. These ultrastructural changes of host tissues and fungal hyphae may reflect the pathogenesis of apple white rot under varying conditions of apple fruits.

Cloning and characterization of tissue inhibitor of metalloproteinase-3 (TIMP-3) from shark, Scyliorhinus torazame

We cloned the full-length cDNA encoding TIMP-3 from the cartilage of cloudy dogfish, Scyliorhinus torazame. The entire open reading frame was composed of 645 nucleotides and 214 residues including 12 conserved cysteines and asparagine-184, a putative site for N-linked sugars. It showed about 72% identity to those of other species based on the deduced amino acid sequence. The mRNA of shark TIMP-3 were expressed abundantly in brain and cartilage tissues. To investigate the roles of shark TIMP-3, an expression vector was constructed and transfected into HT1080 human fibrosarcoma cells. Overexpression of shark TIMP-3 reduced the activity of MMP-2 in gelatin zymography. Through human Alu PCR based CAM assay, we also confirmed that shark TIMP-3 transfected HT1080 cells had less intravasation effects.

Inactivation of farnesyltransferase and geranylgeranyltransferase I by caspase-3: cleavage of the common alpha subunit during apoptosis

Caspase plays an important role in apoptosis. We report here that farnesyltransferase/geranylgeranyltransferase (FTase/GGTase)-alpha, a common subunit of FTase (alpha/beta(FTase)) and GGTase I (alpha/beta(GGTase)), was cleaved by caspase-3 during apoptosis. FTase/GGTase-alpha (49 kDa) was cleaved to 35 kDa (p35) in the Rat-2/H-ras, W4 and Rat-1 cells treated with FTase inhibitor (LB42708), anti-Fas antibody and etoposide, respectively. This cleavage was inhibited by caspase-inhibitors (YVAD-cmk, DEVD-cho). Serial N-terminal deletions and site-directed mutagenesis showed that Asp59 of FTase/GGTase-alpha was cleaved by caspase-3. The common FTase/GGTase-alpha subunit, but not the beta subunits, of the FTase or GGTase I protein complexes purified from baculovirus-infected SF-9 cells was cleaved to be inactivated by purified caspase-3. In contrast, FTase mutant protein complex [(D(59)A)alpha/beta(FTase)] was resistant to caspase-3. Expression of either the cleavage product (60-379) or anti-sense of FTase/GGTase-alpha induced cell death in Rat-2/H-ras cells. Furthermore, expression of (D(59)A)FTase/GGTase-alpha mutant significantly desensitized cells to etoposide-induced death. Taken together, we suggest that cleavage of prenyltransferase by caspase contributes to the progression of apoptosis.

Expression of Fas receptor on disc cells in herniated lumbar disc tissue

STUDY DESIGN

The expression of Fas receptor, an apoptosis-related protein, on disc cells was examined in surgically obtained disc specimens.

OBJECTIVE

To assess the fate of disc cells in herniated disc tissue and the difference in the degree of expression of the Fas receptor between contained and noncontained discs.

SUMMARY OF BACKGROUND DATA

Little is known about the fate of disc cells after herniation.

METHODS

Twenty-three herniated lumbar disc specimens were classified into contained discs (protrusion or subligamentous extrusion; n = 9) and noncontained discs (transligamentous extrusion or sequestration; n = 14). All specimens were stained using the avidin-biotin-peroxidase complex method. The percentage of disc cells positive for Fas receptor was calculated and compared with clinical and radiologic data.

RESULTS

There was a significant difference in the percentage of Fas-positive disc cells between the contained and noncontained discs (8.44 vs.- 14.29;P = 0.044). The percentage of Fas-positive disc cells correlated significantly with the patient's age (r = 0.455, P = 0.029), but not with the degree of disc degeneration on magnetic resonance imaging (r = 0.252, P = 0.214).

CONCLUSION

This is the first study to identify the expression of Fas receptor on disc cells in herniated disc tissue. The results show that the disc cells after herniation may undergo Fas-mediated apoptosis and that the degree of expression of Fas receptor differs depending on the type of herniation.

Protein kinase C suppresses spontaneous, transient, outwards K+ currents through modulation of the Na/Ca exchanger in guinea-pig gastric myocytes

The effect of protein kinase C (PKC) on the Ca2+-activated K+ current (IK,Ca) in guinea-pig gastric myocytes was studied using the whole-cell voltage-clamp technique. At a holding potential of 0 mV, IK,Ca, recorded as spontaneous, transient, outwards currents (STOCs), was markedly inhibited, both in mean amplitude (54 +/- 5%) and frequency (60 +/- 8%) by 1 microM phorbol 12, 13 dibutyrate (PDBu, n = 6). These effects were antagonized by pretreatment with 10 nM bisindolylmaleimide I (n = 5), a selective inhibitor of PKC. The possibility that the inhibition of STOCs was due to direct channel inhibition by PKC was addressed using inside-out or open-cell-attached patch-clamp techniques, the latter established using beta-escin. PDBu did not alter the conductance or open probability of the KCa channel in any mode, suggesting that PKC does not inhibit the KCa channel directly. To study the involvement of the Na/Ca exchanger in the inhibition of STOCs by PDBu, its operation was prevented by replacing Na+ in the internal solution by tris(hydroxymethyl)aminomethane (TRIS) and external Na+ by equimolar K+ and Ca2+-activated inwards K+ currents recorded at a holding potential of 0 mV. Neither the mean amplitude (96 +/- 8%) nor the frequency of these currents was inhibited significantly by 1 microM PDBu (n = 5). Like PDBu, 5 microM 2-(2-[4-(4-nitrobenzyloxy)phenyl]ethyl) isothiourea methanesulphonate (KB-R7943), a selective inhibitor of the reverse mode Na/Ca exchanger, also inhibited the mean amplitude (45 +/- 6%) and frequency (26 +/- 2%) of STOCs at the holding potential of 0 mV (n=6). The results suggest that the suppression of STOCs by PKC is mediated by inhibition of the Na/Ca exchanger.