Biomedical subjects

H Yoshida

Publications and source records attributed to H Yoshida.

At least 343 records · Page 19Linked to original sources

PubMed2000

Hepatitis C virus core protein enhances p53 function through augmentation of DNA binding affinity and transcriptional ability.

Hepatitis C virus (HCV) causes a persistent infection, chronic hepatitis, and hepatocellular carcinoma. Since there are several reports indicating that some viruses influence the tumor suppressor p53 function, we determined the effects of HCV proteins on p53 function and its mechanism determined by use of a reporter assay. Among seven HCV proteins investigated (core, NS2, NS3, NS4A, NS4B, NS5A, and NS5B), only core protein augmented the transcriptional activity of p53 and increased the expression of p21(waf1) protein, which is a major target of p53. Core protein increased both DNA-binding affinity of p53 in electrophoretic morbidity shift assay and transcriptional ability of p53 itself in a reporter assay. The direct interaction between core protein and C terminus of p53 was also shown by glutathione S-transferase fusion protein binding assay. In addition, core protein interacted with hTAF(II)28, a component of the transcriptional factor complex in vivo and in vitro. These results suggest that HCV core protein interacts with p53 and modulates p53-dependent promoter activities during HCV infection.

3T3 Cells↗

PubMed2000

Mechanism for bone invasion of oral cancer cells mediated by interleukin-6 in vitro and in vivo.

BACKGROUND: Osteoclastic bone resorption is an important step in bone invasion in several malignancies. Although interleukin (IL)-6 accelerates osteoclastic bone resorption, it remains unclear whether IL-6 may be involved in bone invasion of oral cancer. METHODS: The pit formation assay with calf femur-derived bone slices was performed to examine the bone-resorbing activity of osteoclasts and cancer cells. The chemotaxis activity of the culture media was analyzed by the use of Boyden chamber technique. Nude mice, which were inoculated with IL-6-producing oral cancer cells into masseter, were treated with anti-IL-6 neutralizing antibody, and mandibular-bone invasion of the cells was assessed. RESULTS: BHY, a bone-invasive oral cancer cell line, but not HNT, a noninvasive cell line, produced large amounts of IL-6. In a pit formation assay, addition of conditioned medium (CM) derived from BHY but not HNT increased osteoclastic bone resorption, and the effects were inhibited by anti-IL-6 antibody. BHY-secreted IL-6 showed significant chemotaxis activity for osteoclasts. Of note, CM from the cocultivation of osteoclasts and BHY markedly enhanced the cancer cell migration, and the chemotaxis activity was significantly reduced when anti-IL-6 antibody was added into the coculture and then CM were collected, but not when the antibody was added into the CM after they were collected. Furthermore, treatment with anti-IL-6 antibody almost completely inhibited mandibular bone invasion of BHY in nude mice. CONCLUSIONS: These results strongly suggest that IL-6 secreted by oral cancer cells plays a significant role in bone invasion.

Animals↗

PubMed2000

The Difference in Saccadic Parameters Among Several Visually Guided Tasks.

Purpose: The present study was undertaken to establish the effects of the five different paradigms (simultaneous, gap, overlap, delayed-memory, and anti-saccade tasks) on saccade dynamics (duration, peak velocity, and amplitude).Methods: We recorded ocular movements in 7 normal subjects, using infrared oculography with a visual stimulation system.Results: The distribution of saccade accuracy in gap and overlap tasks had about the same steepness as that in simultaneous tasks, but that in delayed-memory and anti-saccade tasks was broader than that in simultaneous tasks. The distribution in anti-saccade tasks had a marked intersubject variability, and the average values of accuracy were hypermetric in four subjects. The peak velocity/amplitude ratio in simultaneous and gap tasks were higher than those of other tasks. The relationship between average of peak velocity of abduction and adduction was different, adduction was higher than abduction in simultaneous and gap tasks, and abduction was lower than adduction in delayed-memory and anti-saccade tasks.Conclusions: The dynamics in simultaneous tasks had about the same characteristics as in gap tasks, but were different from those in overlap, delayed-memory, and anti-saccade tasks. These results indicated that the marked differences in dynamic properties among different saccade types may reflect processes in the visuomotor system.

Journal Article↗

PubMed2000

Characterisation of vaccine-derived polioviruses isolated from sewage and river water in Japan.

BACKGROUND: A nucleotide change from U to C at position 472 in the 5' non-coding region of the type 3 poliovirus is associated with increased neurovirulence. Moreover, the proportion of type 3 polioviruses containing this mutation (472-C revertants) correlates with the neurovirulence of a particular sample. We used mutant analysis by PCR and restriction-enzyme cleavage (MAPREC) to estimate the neurovirulence of environmental samples obtained from Toyama prefecture, Japan. METHODS: Sewage and river water were collected between October, 1993, and September, 1995, and concentrated samples were inoculated into three different cell types. Isolated type 3 viruses were analysed to determine whether they were derived from the live oral poliovirus vaccine strain; they were then tested for neurovirulence by MAPREC. RESULTS: 29 type 3 strains were isolated--all of which were vaccine-derived. 16 (55%) comprised between 2% and 91% 472-C revertants by MAPREC and were expected to have high neurovirulence. The remaining strains included less than 0.25% revertants, and were regarded as attenuated viruses. Both types were isolated about 3 months after routine oral poliovirus vaccine administrations in May and October. Three strains isolated from river water were of the virulent type. INTERPRETATION: Our results emphasise that there is an environmental risk of vaccine-associated paralytic poliomyelitis as long as live oral poliovirus vaccine is not replaced by inactivated polio vaccine.

DNA, Complementary↗

PubMed2000

Molecular cloning and expression during development of the Drosophila gene for the catalytic subunit of DNA polymerase epsilon.

We have cloned the genomic DNA and cDNA of Drosophila DNA polymerase epsilon (pol-epsilon) catalytic subunit (GenBank No. AB035512). The gene is separated into four exons by three short introns, and the open reading frame consists of 6660 base pairs (bp) capable of encoding a polypeptide of 2220 amino acid residues. The calculated molecular mass is 255018, similar to that of mammalian and yeast homologues. The deduced amino acid sequence of the pol-epsilon catalytic subunit shares approximately 41% identity with human and mouse homologues as well as significant homology those of C. elegans, S. cerevisiae and S. pombe. Similar to the pol-epsilon catalytic subunits from other species, the pol-epsilon catalytic subunit contains domains for DNA polymerization and 3'-5' exonuclease in the N-terminal region, and two potential zinc-finger domains in the C-terminal regions. Interestingly, a 38 amino acid sequence in the C-terminal region from amino acid positions 1823 to 1861 is similar to the site for Mycoplasma ATP binding and/or ATPase domain (GenBank No. P47365). Northern hybridization analysis indicated that the gene is expressed at the highest levels in unfertilized eggs, followed by zero to 4h embryos and adult females, and then embryos at other embryonic stages, instar larva stages and adult males. Low levels of the mRNA were also detected at the pupa stage. This pattern of expression is similar to those of DNA replication-related enzymes such as DNA polymerase alpha and delta except for the high level of expression in adult males.

Amino Acid Sequence↗

PubMed2000

The Difference in Saccadic Parameters among Several Visually Guided Tasks-Saccadic Reaction Time.

Purpose: The saccadic reaction time (SRT) was measured as a saccadic movement parameter using visually guided tasks.Subjects and Method: The SRT was measured for nine healthy adult subjects aged from 28 to 49 years. The visually guided tasks for saccadic movement induction were simultaneous, gap, overlap, delayed-memory, and anti-SM tasks.Results: The median of the SRT (msec) for each task in the actual measurements was as follows: 216 for the simultaneous task, 180 for the gap task, 240 for the overlap task, 234 for the delayed-memory task, and 292 for the anti-SM task. The SRT distribution of each subject exhibited two peaks for the gap task but mostly one peak for each of the other tasks. The first peak, observed in the SRT distribution for the gap task was an eysress saccade.Conclusion: The SRT for the gap task was the shortest and the SRT got longer in the order of the simultaneous task, and the overlap task, and the anti-SM task. Some subjects easily showed an express saccade in the gap task, but others did not.

Journal Article↗

PubMed2000

Highly selective fluorometric determination of polyamines based on intramolecular excimer-forming derivatization with a pyrene-labeling reagent.

We introduce a novel approach in highly selective and sensitive fluorescence derivatization of polyamines. This method is based on an intramolecular excimer-forming fluorescence derivatization with a pyrene reagent, 4-(1-pyrene)butyric acid N-hydroxysuccinimide ester (PSE), followed by reversed-phase high-performance liquid chromatography (HPLC). Polyamines, having two to four amino moieties in a molecule, were converted to the corresponding dipyrene- to tetrapyrene-labeled derivatives by reaction (100 degrees C, 20 min) with PSE. The derivatives afforded intramolecular excimer fluorescence (450-520 nm), which can clearly be discriminated from the monomer (normal) fluorescence (360-420 nm) emitted from PSE, its hydrolysate and monopyrene-labeled derivatives of monoamines. The structures of the derivatives were confirmed by HPLC with mass spectrometry, and the emission of excimer fluorescence could be proved by spectrofluorometry and time-resolved fluorometry. The PSE derivatives of four polyamines [putrescine (Put), cadaverine (Cad), spermidine (Spd), and spermine (Spm)] could be separated by reversed-phase HPLC on a C8 column with linear gradient elution. The detection limits (signal-to-noise ratio of 3) for the polyamines were 1 (Put), 1 (Cad), 5 (Spd), and 8 (Spm) fmol on the column. Furthermore, the present method was so selective that biogenic monoamines gave no peak in the chromatogram.

Chromatography, High Pressure Liquid↗

PubMed2000

Human adrenomedullin gene delivery protects against cardiac hypertrophy, fibrosis, and renal damage in hypertensive dahl salt-sensitive rats.

Adrenomedullin (AM) is a potent vasodilator expressed in tissues relevant to cardiac and renal functions. Our previous study showed that delivery of the human AM gene in the form of naked DNA caused a prolonged reduction of blood pressure in genetically hypertensive rats. In this study, we evaluated potential protective effects of adenovirus-mediated AM gene delivery on salt-induced cardiorenal lesions in hypertensive Dahl saltsensitive (DSS) rats. Adenovirus carrying the human AM cDNA under the control of the cytomegalovirus promoter-enhancer (Ad.CMV-hAM) was generated by homologous recombination of E. coli. Expression of recombinant human AM was detected by a radioimmunoassay in the medium of human embryonic kidney 293 cells transfected with Ad.CMV-hAM. A single intravenous injection of Ad.CMV-hAM caused a significant reduction of systolic blood pressure for 4 weeks in DSS rats compared with control rats with or without injection of adenovirus carrying the green fluorescent protein gene. AM gene delivery significantly reduced left ventricular mass and urinary protein, increased cAMP levels, and enhanced renal function as evidenced by increases in glomerular filtration rate and renal blood flow. Morphological investigations showed that AM gene transfer reduced cardiomyocyte diameter and interstitial fibrosis in the heart as well as glomerular sclerosis, tubular disruption, and protein cast accumulation in the kidney. Expression of human AM mRNA was identified in rat heart, kidney, lung, liver, and aorta, and immunoreactive human AM levels were measured in rat plasma and urine. These results indicate that human AM gene delivery protects against salt-induced hypertension and cardiac and renal lesions in DSS rats via activation of cAMP as a second messenger. These findings provide new insights into the role of AM in salt-induced hypertension and may have implications in therapeutic applications to salt-related cardiovascular and renal diseases.

Adenoviridae↗

PubMed2000

Peroxiredoxin I expression in oral cancer: a potential new tumor marker.

This study investigates the applicability of the novel antioxidant protein, peroxiredoxin (Prx) I as a marker for tumor status in oral squamous cell carcinoma (SCC). Samples from 53 patients with SCC in the oral cavity were examined by immunohistochemistry. Correlations between the expression level of Prx I and proliferating cell nuclear antigen (PCNA), the clinical features of tumors, and their histopathological classifications were statistically analyzed. Cases exhibiting low Prx I expression level included significantly more with larger tumor mass cases (T-category, P=0.004), positive lymph node metastasis (N-category, P=0.015), advanced stage (P=0.002), and poorly differentiated cells (P=0.020). There was no significant difference between Prx I expression and the other indices.

Adult↗

PubMed2000

Increased frequency of surface IgA-positive plasma cells in the intestinal lamina propria and decreased IgA excretion in hyper IgA (HIGA) mice, a murine model of IgA nephropathy with hyperserum IgA.

Because abnormalities of mucosal immunity have been suggested in human IgA nephropathy, we examined the involvement of mucosal immunity in IgA deposition to the kidney in hyper IgA (HIGA) mice, which was established as a mouse model for human IgA nephropathy with hyperserum IgA. The number of surface IgA+B220- lymphocytes in the intestinal lamina propria (LP) of HIGA mice increased 2.7-fold at 30 wk of age as compared with those at 10 wk of age, whereas normal mice did not show such increase. The surface IgA+B220- LP lymphocytes spontaneously secreted IgA in culture. Morphological studies showed that the surface IgA+B220- lymphocytes of murine intestinal LP are identical with plasma cells (PCs). About 20% of IgA+B220- PC in LP expressed both Mac-1 and CD19, suggesting that they may derive from peritoneal B-1 cells. Cell cycle study on intestinal IgA-PCs using bromodeoxyuridine revealed no difference between HIGA mice and normal mice, suggesting that the high frequency of IgA-producing PCs in HIGA mice is not due to enhanced proliferation or prolonged survival of IgA-producing PCs in LP. In addition, IgA secretion into the gut lumen of HIGA mice decreased drastically (to one forth) with aging. These data suggest that the increased number of intestinal IgA-producing PCs and the down-regulation of IgA excretion into the intestinal lumen might synergistically contribute to the hyperserum IgA in HIGA mice and resultant IgA deposition to the kidney.

Animals↗

PubMed2000

Cytokines prevent dexamethasone-induced apoptosis via the activation of mitogen-activated protein kinase and phosphatidylinositol 3-kinase pathways in a new multiple myeloma cell line.

A new human myeloma cell line, OPM-6, was established from the peripheral blood of a patient with advanced IgG-kappa plasma cell leukemia. Cytogenetic and phenotypic analysis confirmed that the cells were derived from the patient's leukemic cells. Insulin-like growth factor-1 (IGF-1) acts as an autocrine growth factor in these cells. In addition, OPM-6 cells were particularly sensitive to dexamethasone (DEX), when endogenous IGF-1 was blocked. Under these conditions, >95% of the DEX-treated cells died within 36 h. Therefore, OPM-6 represents a potentially powerful tool for the analysis of the molecular mechanisms of DEX-induced apoptosis, because it is possible to easily analyze the direct effects of DEX using this system. Using this culture system of OPM-6, we demonstrated that the treatment with DEX plus a monoclonal antibody to the human IGF-1 receptor (alphaIGF-1R) leads to the down-regulation of the gene expression of Bcl-xL, an antiapoptotic gene, and the activation of CPP32 during this apoptotic process. IFN-alpha as well as IL-6 prevented DEX plus alphaIGF-1R-induced apoptosis, and this prevention was blocked by the mitogen-activated protein kinase kinase inhibitor, PD098059, or the phosphatidylinositol 3-kinase inhibitor, wortmannin. Therefore, both IL-6 and IFN-alpha blocked DEX plus alphaIGF-1R-induced apoptosis through activation of the mitogen-activated protein kinase and phosphatidylinositol 3-kinase pathways.

Aged↗

PubMed2000

Mechanistic aspects of palladium-catalyzed allylstannylation of alkynes

An alpha-methylallylstannane added to an alkyne in the presence of a palladium catalyst with perfect regioselectivity both in the allylic and alkynic moieties. Comparison of the reaction of isomeric butenylstannanes suggests two catalytic cycles, one of which includes a palladacyclopentene intermediate and beta-tin elimination pathway.

Journal Article↗

PubMed2000

Fas and Fas ligand mutations inhibit autoantibody production in pristane-induced lupus.

Mutations of Fas (lpr) or Fas ligand (gld) cause a limited lupus-like syndrome in B6 mice by interfering with the deletion of autoreactive B and/or T cells. A more generalized lupus syndrome reminiscent of that of MRL mice can be induced in nonautoimmune strains by pristane, which causes a nonspecific inflammatory response in the peritoneal cavity. We hypothesized that, as in MRL mice, the lpr and gld mutations might accelerate lupus in pristane-treated mice. Pristane-treated B6 mice developed anti-nRNP/Sm, Su, and ribosomal P Abs, but little anti-ssDNA or chromatin. In contrast, B6/lpr and B6/gld mice spontaneously developed anti-ssDNA/chromatin Abs, but not anti-nRNP/Sm/Su/ribosomal P. Unexpectedly, B6/lpr and B6/gld mice were highly resistant to the induction by pristane of IgM anti-ssDNA (2 wk) and IgG anti-nRNP/Sm/Su/ribosomal P autoantibodies (6 mo), suggesting that intact Fas signaling is necessary. Interestingly, pristane did not enhance IgG chromatin Ab production in B6/lpr or B6/gld mice, suggesting that it did not influence the production of autoantibodies that develop spontaneously in the setting of Fas deficiency. Pristane treatment also decreased lymphoproliferation in B6/lpr mice. Increased production of IL-12 was associated consistently with the production of anti-nRNP/Sm/Su/ribosomal P as well as anti-DNA/chromatin. In contrast, production of anti-DNA/chromatin Abs was associated with IL-6 overproduction in pristane-treated mice, but not in lpr mice. The data strongly support the idea that different subsets of autoantibodies are regulated differentially by cytokine stimulation and/or Fas signaling.

Animals↗

PubMed2000

Functional Fv fragment of an antibody specific for CD28: Fv-mediated co-stimulation of T cells.

The most predominant co-stimulation pathway, which is critical for T cell activation and proliferation, is the CD28-B7 pathway. The anti-CD28 monoclonal antibody (mAb) also provides a co-stimulatory signal to T cells. In order to construct a functional Fv fragment (complex of VH and VL domains) of anti-CD28 antibody using a bacterial expression system, cDNA encoding the variable regions of immunoglobulin from 15E8 hybridoma cells was cloned and expressed in Escherichia coli. The Fv fragment was obtained as a soluble protein from the periplasmic fraction and showed a binding pattern similar to parental IgG. The Fv fragment induced proliferation of peripheral blood mononuclear cells in the presence of anti-CD3 or anti-CD2 mAb and enhanced anti-tumor activity of anti-MUC1x(anti)-CD3 bispecific antibody when tested with lymphokine-activated killer cells with T cell phenotype. Thus, the anti-CD28 Fv fragment will be promising not only for the study of co-stimulation, but also for cancer immunotherapy.

Amino Acid Sequence↗

PubMed2000

Integrin-associated protein/CD47 regulates motile activity in human B-cell lines through CDC42.

Cell migration requires a dynamic interaction between the cell, its substrate, and the cytoskeleton-associated motile apparatus. Integrin-associated protein (IAP)/CD47 is a 50-kd cell surface protein that is physically associated with beta3 integrins and that modulates the functions of beta3 integrins in various cells. However, in B-lymphocytes that express beta1 integrins but few beta3 integrins, the roles of IAP/CD47 remain to be determined. Cross-linking of IAP/CD47 by the immobilized anti-IAP/CD47 monoclonal antibody (mAb) B6H12, but not 2D3, produced signals to promote polarization with lamellipodia, a characteristic morphology during leukocyte migration, in pre-B and mature B-cell lines (BALL, Nalm6, ONHL-1, Daudi), but not in myeloma cell lines (RPMI8226, OPM-2). In the presence of the immobilized fibronectin (FN), soluble B6H12 could increase the rate of the polarization and activate migratory activity of BALL cells to FN in a transwell filter assay. Furthermore, the dominant-negative form of CDC42 completely blocked B6H12-induced morphologic and functional changes without inhibiting phorbol 12-myristate 13-acetate-induced spreading on FN in BALL cells, whereas the dominant-negative form of Rac1 inhibited all these changes. These findings demonstrate that in B-lymphocytes, IAP/CD47 may transduce the signals to activate the migratory activity, in which CDC42 may be specifically involved, and that IAP/CD47 shows synergistic effect with alpha4beta1 on B-cell migration. These findings would provide new insight into the role of IAP/CD47 on B-cell function.

Antibodies, Monoclonal↗

PubMed2000

A possible role for Ca(2+)/calmodulin-dependent protein kinase IV during pancreatic acinar stimulus-secretion coupling.

Ca(2+)/calmodulin-dependent protein kinases (CaMKs) are important intracellular mediators in the mediation of stimulus-secretion coupling and excitation-contraction coupling in a wide variety of cell types. We attempted to identify and characterize the functional roles of CaMK in mediating pancreatic enzyme secretion. Immunoprecipitation and immunoblotting studies using a CaMKII or CaMKIV antibody showed that rat pancreatic acini expressed both CaMKII and CaMKIV. Phosphotransferase activities of CaMKs were measured by a radioenzyme assay (REA) using autocamtide II, peptide gamma and myosin P-light chain as substrates. Although CaMKII and CaMKIV use autocamtide II as a substrate, peptide gamma is more efficiently phosphorylated by CaMKIV than by CaMKII. Intact acini were stimulated with cholecystokinin (CCK)-8, carbachol (CCh) and the high-affinity CCK-A receptor agonist, CCK-OPE, and the cell lysates were used for REA. CCK-8, CCh and CCK-OPE caused a concentration-dependent increase in CaMKs activities. When autocamtide II was used, maximal increases were 1.5-1.8-fold over basal (20.2+/-2.0 pmol/min/mg protein), with peaks occurring at 20 min after cell stimulation. In separate studies that used peptide gamma, CCK-8, CCh and CCK-OPE dose-dependently increased CaMKIV activities. Maximal increases were 1.5-2.4-fold over basal (30.7+/-3. 2 pmol/min/mg protein) with peaks occurring at 20 min after cell stimulation. Peak increases after cell stimulation induced by peptide gamma were 1.8-2.8-fold higher than those induced by autocamtide II. CCK-8, CCh and CCK-OPE also significantly increased phosphotransferase activities of myosin light chain kinase (MLCK) substrate (basal: 4.4+/-0.7 pmol/min/mg protein). However, maximal increases induced by MLCK substrate were less than 10% of those occurring in peptide gamma. Characteristics of the phosphotransferase activity were also different between autocamtide II and peptide gamma. When autocamtide II was used, elimination of medium Ca(2+) in either cell lysates or intact cells resulted in a significant decrease in the activity, whereas it had no or little effect when peptide gamma was used. This suggests that Ca(2+) influx from the extracellular space is not fully required for CaMKIV activity and Ca(2+) is not a prerequisite for phosphotransferase activity once CaMKIV is activated by either intracellular Ca(2+) release or intracellular Ca(2+) oscillations. The specific CaMKII inhibitor KN-62 (50 microM) had no effect on the CaMKIV activity and pancreatic enzyme secretion elicited by CCK-8, CCh and CCK-OPE. The specific MLCK inhibitor, ML-9 (10 microM), also did not inhibit CCK-8-stimulated pancreatic amylase secretion. In contrast, wide spectrum CaMK inhibitors, K-252a (1 microM) and KT5926 (3 microM), significantly inhibited CaMKIV activities and enzyme secretion evoked by secretagogues. Thus, CaMKIV appears to be an important intracellular mediator during stimulus-secretion coupling of rat pancreatic acinar cells.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed2000

Apoptotic protease activating factor 1 (Apaf-1)-independent cell death suppression by Bcl-2.

Reportedly, antiapoptotic Bcl-2 family proteins suppress apoptosis by binding to and inhibiting members of the CED-4 family of caspase activators. To explore this question, we used embryonic stem (ES) cells in which one (-/+) or both (-/-) copies of the gene encoding apoptotic protease activating factor 1 (Apaf-1), a CED-4 homologue, were disrupted by homologous recombination. Stable clones of heterozygous (-/+) and homozygous (-/-) Apaf-1 knockout ES cells that overexpressed Bcl-2 were generated. Withdrawal of serum growth factors or stimulation of heterozygous ES cells with staurosporine (STS), ultraviolet (UV)B irradiation, etoposide (VP16), or cisplatin induced apoptosis followed by cell death (determined by failure to exclude propidium iodide dye). These cell death stimuli also induced activation of several types of caspases and loss of mitochondrial membrane potential (DeltaPsi) in heterozygous (+/-) Apaf-1 knockout ES cells. In addition, overexpression of Bcl-2 protected against these events in Apaf-1-expressing ES cells. In contrast, STS, UVB, and VP16 induced little or no caspase activation and apoptosis in homozygous (-/-) Apaf-1 knockout ES cells. Nevertheless, Apaf-1-deficient ES cells subjected to these cell death stimuli or deprived of growth factors did eventually die through a nonapoptotic mechanism associated with loss of DeltaPsi. Moreover, Bcl-2 overprotection preserved DeltaPsi, reduced the percentage of Apaf-1(-/)- ES cells undergoing cell death, and increased clonigenic survival. The extent of Bcl-2-mediated cytoprotection was not significantly different for heterozygous (-/+) versus homozygous (-/-) Apaf-1 knockout cells. Furthermore, although Bcl-2 could be readily coimmunoprecipitated with Bax, associations with Apaf-1 were undetectable under conditions where Apaf-1 interactions with procaspase-9 were observed. We conclude that Bcl-2 has cytoprotective functions independent of Apaf-1, preserving mitochondrial function through a caspase-independent mechanism.

Amino Acid Sequence↗

PubMed2000

Dietary intake of rapeseed oil or soybean oil as the only fat nutrient in spontaneously hypertensive rats and Wistar Kyoto rats - blood pressure and pathophysiology.

Spontaneously hypertensive rats (SHR) and Wistar Kyoto (WKY) rats were fed a diet containing 10% rapeseed (canola) oil or soybean oil as dietary fat, and given drinking water containing 1% NaCl for 26 weeks. From the 10th week and later, systolic blood pressure in the canola oil group became higher than that in the soybean oil group in each strain. The 26-week feeding of canola oil increased plasma lipids and the neutrophil counts, and decreased the platelet counts. In the canola oil group the heart and kidney tended to become heavier with sporadically found histologic lesions. Acetylcholine- and nitroprusside-induced dilating responses of isolated aortic rings and norepinephrine- and veratridine-induced increases in vascular tone of isolated perfused mesenteric arteries were not different between the two groups in each strain. These results demonstrate that canola oil intake as the only dietary fat elevates blood pressure of the rat provided with drinking water containing 1% NaCl through mechanisms other than blunt dilating response of the blood vessel due to dysfunction of the endothelium or vascular smooth muscle, the augmented response to norepinephrine in the arteries and the increased amount of norepinephrine in the sympathetic nerve endings. The lesions in the heart and kidney in SHR may be related to a strain-specific peripheral vascular deterioration which was disclosed by the extremely high blood pressure in the canola oil group.

Acetylcholine↗