Enhancement of apoptosis in developing chick neural retina cells by basic fibroblast growth factor

To evaluate the role of various growth factors in naturally occurring cell death during development of the neural retina, we examined the effects of such factors on the nuclear morphology and the size of DNA in cultured chick embryonic neural retina cells. Basic fibroblast growth factor (bFGF) increased internucleosomal cleavage of DNA and nuclear fragmentation in a time- and dose-dependent manner. The effect was inhibited by anti-bFGF antibody, suramin, and cycloheximide. Epidermal growth factor, platelet-derived growth factor, nerve growth factor, tumor necrosis factor-alpha, and dexamethasone had no effect. These results provide evidence that bFGF may eventually act as a lethal factor inducing apoptotic cell death during the development of the neural retina in chick embryo.

Integrin beta4 is involved in apoptotic signal transduction in endothelial cells

To clarify the signal transduction in vascular endothelial cells (VEC) apoptosis induced by deprivation of FGF and serum, we investigated the function of integrin beta4 by using the monoclonal antibody (mAb) of this integrin. We added anti-beta 4 integrin mAb at the concentration of 5 microg/ml to the cells deprived of FGF and serum, apoptosis of these cells were completely inhibited 24 h after the treatment. Furthermore we plated the cells onto untreated bacterial culture plates on which the cells cannot adhere and spread in MCDB medium without FGF and serum; however, when anti-beta 4 integrin mAb was present at 5 microg/ml in the seeding medium, the cells rapidly adhered and spread. Our results first demonstrated that integrin beta4 participated in apoptotic signaling in VEC, and our findings indicate that hemidesmosome structures and keratin filament system might be important in regulation of apoptotic signaling.

Inhibitors of phospholipase promote apoptosis of human endothelial cells

In order to understand the signal transduction system that regulates apoptosis of human umbilical vein endothelial cells (HUVEC), we investigated the effects of inhibitors of the activity of phospholipases. All three tested inhibitors of phospholipase A2 (PLA2), namely, manoalide, 3-(4-octadecyl)benzoylacrylic acid (OBAA), and oleyoxyethylphosphorylcholine (OOPC), induced apoptotic cell death of HUVEC. After 16 h of treatment, almost all of the cells had disintegrated into apoptotic bodies, and DNA ladders characteristic of apoptotic cell death were clearly observed upon analysis of DNA on agarose gels. The release of arachidonic acid from the cells that had been treated with manoalide, OBAA or OOPC (at the same concentrations as those at which these compounds induced apoptosis) was inhibited. We also studied the effects of two inhibitors of phosphatidylinositol-specific phospholipase C (PLC), U73122, and compound 48/80. Both compounds promoted the apoptosis of HUVEC. After 16 h of treatment, few cells remained intact, and DNA fragmentation was clearly detectable after only 12 h. Quantitation of inositol released from cells treated with U73122 and compound 48/80 showed that the release of inositol was blocked. By contrast, U73343, a similar aminosteroid that does not inactivate PLC, had no such effects. Our results suggest that PLA2 and phosphatidylinositol-specific PLC might be involved in the signaling pathway of apoptosis in HUVEC, and that the metabolism of arachidonic acid and of inositol might play important roles in the present apoptotic signal-transduction system.

Gestational age determination, variation of conception date, and external fetal development of sika deer (Cervus nippon yesoensis Heude, 1884) in eastern Hokkaido

The authors determined gestational age from fetal weight, examined the range in conception dates, and classified the external fetal development process in sika deer of eastern Hokkaido. Gestational age (T) can be estimated from fetal weight (W) with the equation: T = (3 square root of W + 2.730)/0.091. Conception date can then be calculated back from date of kill of pregnant female, using gestational age. Though estimated conception dates ranged from 7 October to 17 January, most of them were concentrated between mid October and early November. In late November and after, nine conceptions were observed and six out of the nine late cases occurred in yearling females. This phenomenon is probably due to the excellent nutritional condition of deer in the study areas, which allows yearling females to mature sexually even in early winter. In fetuses, periods of tactile hair development, appearance of white spots, and development of general hairs overlap very little. In addition, these developmental changes occur at specific fetal weights. Based on these external phases, the gestation period can be divided into four stages. These stages will be useful for simple determination of fetal age in various sika deer populations.

Hemosiderin deposition in portal endothelial cells: a novel hepatic hemosiderosis frequent in chronic viral hepatitis B and C

We have recently noted a hitherto undescribed hepatic hemosiderosis confined to endothelial cells of the portal tract in chronic viral hepatitis. In this study, this lesion was surveyed in 156 liver biopsy specimens from patients with chronic hepatitis C and in 21 liver biopsy specimens from patients with chronic hepatitis B. As controls, we examined 110 liver biopsy specimens from patients with primary biliary cirrhosis (PBC), 36 from patients with alcoholic liver injury, nine from patients with autoimmune hepatitis (AIH), and five from patients with primary hemochromatosis. Hemosiderin deposition was found in the endothelial cells of venous vessels in portal tracts regardless of the presence or degree of hemosiderin deposition in hepatic parenchyma. This phenomenon was observed in 65 of 156 cases (42%) of chronic hepatitis C and in eight of 21 (38%) cases of chronic hepatitis B. In controls, this lesion was frequent in AIH (78%), but infrequent in PBC (8.1%) and alcoholic liver injury (11%). The incidence of this lesion showed significant differences between chronic hepatitis C, B, and AIH, and between PBC and alcoholic liver injury. There was a positive correlation between the progression of disease and the incidence of this feature in chronic viral hepatitis; the incidence was 18.3% and 11.1% in milder chronic hepatitis C and B, respectively, and 61.2% and 58.3%, respectively, in more severe cases. However, this correlation was not evident in either PBC or alcoholic liver injury. This hemosiderin deposition was positively correlated with the degree of piecemeal necrosis in chronic hepatitis C, and to a lesser degree, the positive correlation was shown in chronic hepatitis B. These findings suggest that the progression of chronic hepatitis and the piecemeal necrosis in chronic hepatitis C and B, followed by the release of hepatocellular iron to portal and periportal areas, are directly or indirectly responsible for endothelial hemosiderosis. Further studies focusing on this peculiar phenomenon in relation to choice of therapy and evaluation of chronicity of viral hepatitis are encouraged.

Age related decline in cytokine induced nitric oxide synthase activation and apoptosis in cultured endothelial cells: minimal involvement of nitric oxide in the apoptosis

Nitric oxide synthase (NOS) activity was enhanced in human umbilical vein endothelial cells (HUVECs) by the combined stimulation with IFN-gamma plus IL-1beta, TNF-alpha and LPS which was accompanied by cell death. DNA analysis of the NOS induced dead HUVECs showed that internucleosomal DNA fragmentation had occurred, suggesting that apoptosis was taken place. The enhanced NO production seemed to be associated with the death of HUVECs, however, both NG-methyl-L-arginine (L-NMMA) and nitro-L-arginine (N-arg), inhibitors of NOS, recovered the death of HUVECs by only 16%, suggesting that NO production was minimally involved in the cytokine induced apoptosis of HUVECs. Additional results demonstrated that both the induction of NOS activity and apoptosis in HUVECs declined with in vitro aging, i.e. declined with increasing PDLs of HUVECs, which may explain the decreased immunity during inflammation in aged people.

Species difference in the resistibility of embryonic fibroblasts against oxygen-induced growth inhibition

The growth of fibroblasts, which were isolated from human, rabbit, rat, mouse, and chick embryos, was inhibited partially under 50% oxygen and nearly completely under 95% oxygen. There was species difference in the resistivity of these cells against oxygen-induced growth inhibition. The extent of the resistivity was in the following order: chick cells > rat cells > human cells > rabbit cells approximately mouse cells. The order of their ability to recover from oxygen-induced growth inhibition was similar to the above order of species. There was also species difference in their antioxidant enzyme activities, including superoxide dismutase, catalase, and glutathione peroxidase activities, and their reduced glutathione concentration. Chick cells, having the highest resistivity against oxygen-induced growth inhibition, were at the lowest activity levels of antioxidant enzymes and at the highest concentration level of reduced glutathione. The species difference in resistivity against oxygen-induced growth inhibition seems to depend on the reduced glutathione concentration, but not on the antioxidant enzyme activities.

Hepatitic bile duct injuries in chronic hepatitis C: histopathologic and immunohistochemical studies

Interlobular bile ducts are reported to be damaged in viral hepatitis. Such damages are called hepatitic duct injuries and mimic chronic nonsuppurative destructive cholangitis of primary biliary cirrhosis. In this study, hepatitic bile duct injuries were evaluated histopathologically and immunohistochemically in 149 needle liver biopsy specimens from patients with chronic hepatitis C and compared immunohistochemically with primary biliary cirrhosis. Fifty-one of the needle biopsies from patients with chronic hepatitis C (34.2%) showed hepatitic bile duct injuries which were distributed focally in the liver and showed variable epithelial damages such as cytoplasmic swelling, vacuolation and acidophilia, nuclear pleomorphism, and loss of nuclear polarity. Some of the injured bile ducts were embedded within lymphoid aggregates, whereas others were surrounded by lymphocytes as well as other inflammatory cells to varied degrees. The majority of lymphoid cells around hepatitic bile duct injury were B- and T-cells mixed in various proportions, and activated T-cells were occasionally found within the biliary epithelial layer. Histopathologic and serial section studies disclosed that bile duct loss was rare in chronic hepatitis C. Statistical analysis revealed that advancement of chronic hepatitis and the degree of necroinflammatory processes of the liver, particularly in the portal tracts, were positively correlated with the occurrence of hepatitic bile duct injuries. Immunohistochemical studies demonstrated that, whereas strong ectopic expression of HLA-DR and enhanced expression of HLA-A,B,C, and pyruvate dehydrogenase E2-complex in biliary epithelial cells were frequently observed in chronic nonsuppurative destructive cholangitis of primary biliary cirrhosis, such unusual expressions were generally absent or mild, even if present, in bile duct injuries in chronic hepatitis C.(ABSTRACT TRUNCATED AT 250 WORDS)

Classification of signals for blocking apoptosis in vascular endothelial cells

The survival and death of human umbilical vascular endothelial cells in culture are affected by several factors, such as fibroblast growth factor (FGF), serum, phorbol ester (TPA), and vanadate. In order to identify common aspects of the various signal-transduction processes during the course of apoptotic or programmed cell death, we designed experiments to distinguish between these factors in terms of the pathway that is responsible for the processing of each stimulus. We found, for example, that the effect of removal of FGF was specifically overcome by the addition of the phorbol ester. Our results indicated that two distinct pathways were operative, one specific for signal transduction initiated by FGF and phorbol ester and another specific for signal transduction initiated by serum and vanadate. These two pathways merged down-stream of the individual signal-processing pathways.

Activation of the alternative pathway of human complement by apoptotic human umbilical vein endothelial cells

Complement activation generally does not occur on homologous cells. We observed C3 deposition on cultured human umbilical vein endothelial cells (HUVEC) when those which had died of apoptosis were treated with human serum. The C3 deposition on apoptotic HUVEC required Mg2+ but not Ca2+. In addition, the incubation of apoptotic HUVEC with purified C3, B, and D in the presence of Mg2+ resulted in C3 deposition. These results indicated that the C3 deposition on apoptotic HUVEC is mediated by the activation of the alternative complement pathway. C3 contains an intrachain thioester bond in the alpha chain (110 kDa) and upon activation to C3b, binds with membrane molecules by forming an ester or amide bond. Western blotting of reduced C3b-membrane molecule complexes, isolated from serum-treated apoptotic HUVEC by immunoprecipitation with anti-C3, revealed the covalent binding of C3b to several membrane molecules. Most of the C3b-membrane molecule complexes were cleaved by hydroxylamine, suggesting covalent binding via an ester bond. The molecular mass of the major alpha chain fragment released by hydroxylamine treatment was not 105 kDa but 68 kDa, which corresponds to the alpha 1 fragment of iC3b. These results indicate that most of the C3b on HUVEC was cleaved at its alpha' chain to yield iC3b, which consists of three disulfide-linked polypeptide chains and is a ligand of the complement receptor type 3 (CR3) of phagocytes. These results suggest that apoptotic HUVEC can activate the alternative pathway of the homologous complement and that the complement is related to the clearance of apoptotic cells by phagocytes.

Increased expression of nucleoside diphosphate kinases/nm23 in human diploid fibroblasts transformed by SV40 large T antigen or 60Co irradiation

When the expression levels of nucleoside diphosphate (NDP) kinase/nm23 were examined in four human normal diploid fibroblast cell lines in comparison with their corresponding immortalized cells transformed by SV40 large T antigen or 60Co irradiation, mRNA levels of the two isoforms (NDP kinase A/nm23-H1, NDP kinase B/nm23-H2) were increased in the immortalized cell lines. The increase was found to be associated with increased translation products. Furthermore, the cell extracts prepared from these immortalized cell lines demonstrated slightly higher enzyme activity than those from their normal counterparts. Neither the growth state nor the in vitro aging largely affected their expression in a normal cell line (TIG-3) examined. The results suggest possible involvement of NDP kinases/nm23 in acquiring an infinite growth property of these cells.

A novel human gene that is preferentially transcribed in heart muscle

We have cloned a human cDNA fragment for a gene that is expressed primarily in the heart. To explore its biological function, we have isolated full-length cDNA clones of the gene. DNA sequencing of the 2.7-kb cDNA revealed a 2274-bp ORF. Close to the N terminus of the deduced amino acid sequence is a possible ATP-binding domain that has been assembled by a fusion of B- and A-type adenine nucleotide-binding motifs. In the middle of the sequence is a long stretch of alpha-helical residues that could form a coiled-coil. These features imply that this is a sequence encoding a new human motor protein.

[Autoimmune hepatitis with hepatitis C virus markers (anti HCV antibody or HCV-RNA) and interferon therapy]

Autoimmune hepatitis (AIH) with hepatitis C virus (HCV) markers are seen frequently after the establishment of the method to detect HCV markers. According to the mechanism of the liver injury, we divide these cases of AIH with HCV markers to three groups; 1) the cases of AIH with HCV infection incidentally, 2) the cases of AIH triggered by HCV infection, and 3) the cases of chronic hepatitis C with immunological abnormalities. As far as we don't have any markers to differentiate these cases, we now think we should treat such cases with steroids at first before administering interferon, when we are not sure about the mechanism of the liver injury, because interferon is thought to be more risky than steroid for the cases who may have immunological abnormalities.

Frequent occurrence of hepatocellular carcinoma in cirrhotic livers after surgical resection of atypical adenomatous hyperplasia (borderline hepatocellular lesion): a follow-up study

OBJECTIVES

Adenomatous hyperplasia (AH) of the liver occurs in chronic advanced liver diseases, and has been suspected to be a precancerous lesions in human hepatocarcinogenesis.

METHODS

In this study, the incidence of hepatocellular carcinoma (HCC) after surgical resection of AH was evaluated in 24 patients with cirrhosis and AH in the absence of HCC (mean follow-up period, 31.4 months; range, 12-77 months). AH were classified as ordinary AH lacking hepatocellular atypia (OAH), atypical AH with structural and cellular atypia insufficient for carcinoma (AAH), and atypical AH with focal malignancy containing areas of HCC (FM).

RESULTS

HCC was noted in a few years (follow-up period range, 12-77 months; mean, 31.4 months) in all 3 patients whose resected nodules were classified as FM, in 4 (36%) of 11 with AAH resected nodules, and none of 10 with OAH resected nodules. The incidence of HCC in the patients with FM or AAH nodules was significantly higher than that in those with OAH nodules.

CONCLUSIONS

These results suggest that our classification of AH is useful in the assessment of the risk of HCC in patients with cirrhosis and AH, and that those with AAH or FM resected nodules must be followed up more frequently than those with OAH nodules, because of their higher risk of HCC. The frequent occurrence of HCC after resection of FM or AAH nodules may imply that HCC is of multicentric origin.

Increase in production of hepatocyte growth factor by human embryonic lung fibroblasts in the process of aging in culture

It was determined whether human hepatocyte growth factor (hHGF)-producing ability would change in the human embryonic lung fibroblast cell strains (MRC-5 and IMR-90) until the cells senesced in culture. The effects of phorbol 12-myristate 13-acetate (PMA), dexamethasone, and transforming growth factor-beta 1 (TGF-beta 1) on hHGF production were also studied in these cell strains. For stimulation of DNA synthesis of adult rat hepatocytes in primary culture, hHGF secreted by MRC-5 cells at 39.9 and 69.8 population doubling levels (PDLs) showed almost the same activity as recombinant hHGF. Secretion of hHGF by MRC-5 cells increased about threefold between 37.3 and 67.8 PDLs. IMR-90 cells also showed about a threefold increase in hHGF secretion with increased passage from 37.8 to 66.0 PDL. Both cell strains showed almost the same ratio of hHGF amount in the cell extracts to that secreted into the medium around 40 and 70 PDLs. Northern blot analysis showed that the transcriptional level of the hHGF gene in MRC-5 cells increased about three-fold from 42.0 to 73.6 PDL in culture. These findings indicated that hHGF production increased in both cell strains with aging in culture. Production of hHGF in both cell strains was remarkably stimulated by treatment with 10 nM PMA. On the other hand, hHGF production in both cell strains was slightly suppressed by treatment with 1 microM dexamethasone. TGF-beta at a concentration of 5 ng/ml prominently inhibited hHGF production in both cell strains. The response of both cell strains to these regulators for hHGF production was almost the same around 40 and 70 PDLs in culture.

Protection of linoleic acid hydroperoxide-induced cytotoxicity by phenolic antioxidants

The protective effects of phenolic antioxidants on linoleic acid hydroperoxide (LOOH)-induced toxicity to cultured human umbilical vein endothelial cells were examined. Our previous results were confirmed that for tocopherol homologs, lipophilicity and the presence of a phenolic hydroxyl group and two alkyl groups at its ortho positions are critical for protection against LOOH-induced cytotoxicity. Probucol and butylated hydroxytoluene (BHT) were more effective than other simple alkylated phenols. It was found that the protective effects of alkylated phenols were depended on by the presence of two alkyl groups; in particular, two tert-butyl groups, at positions ortho to a hydroxyl group and an alkyl group at the para position. Among alpha-tocopherol, 2,2,5,7,8-pentamethylchroman-6-ol, and BHT, the relative effectiveness of protection against the cytotoxicity (1.0:0.86:0.58, respectively) was inconsistent with the previously reported, relative antioxidant activity in homogeneous solution (1.0:1.2:0.004, respectively). Probably, the effectiveness of protection by phenolic antioxidants against the cytotoxicity depend primarily on their incorporation rate into cells due to their lipophilicity, secondly on their antioxidant activity, and thirdly on their orientation in biomembranes.

Decay-accelerating factor on human umbilical vein endothelial cells. Its histamine-induced expression and spontaneous rapid shedding from the cell surface

Decay-accelerating factor (DAF) is a membrane protein that protects host cells from attack by its own complement. Although DAF expression on endothelial cells is thought to increase pathophysiologically, little is known about the natural mediators that modulate DAF expression on endothelial cells. In this study, we evaluated the effect of histamine on DAF expression on human umbilical vein cells (HUVEC). HUVEC were cultured with histamine, and DAF expression on HUVEC was determined by flow cytometry after immunostaining with a mAb to DAF. DAF expression on HUVEC was increased at 10 microM histamine, and the final level was increased time-dependently by 150% to 200% after a 24-h incubation with 100 microM histamine. The histamine-induced DAF expression was inhibited by actinomycin D and cycloheximide and accompanied by an increase in the DAF mRNA level, indicating that both transcription and translation are required. In addition, the histamine-induced DAF expression was inhibited by pyrilamine, an H1 blocker, but not by cimetidine, an H2 blocker, indicating that histamine induces the DAF expression through H1 receptors. We also demonstrated that the turnover of DAF is faster than that of MCP and CD59, and DAF is released into the culture supernatant. DAF is a glycosylphosphatidylinositol-linked protein that is released from HUVEC by a phosphatidylinositol-specific phospholipase C. Although HUVEC also contain the glycosylphosphatidylinositol-anchored complement inhibitor CD59, this was not released during a 24-h incubation, suggesting that the shedding of DAF from HUVEC is not caused by PI-PLC but by other enzymes, possibly proteinases. These results suggest that histamine, which is released from mast cells and basophils by complement-derived anaphylatoxins, increases the complement defense ability of endothelial cells by increasing their levels of DAF expression.

Decay-accelerating factor on human umbilical vein endothelial cells. Its histamine-induced expression and spontaneous rapid shedding from the cell surface

Decay-accelerating factor (DAF) is a membrane protein that protects host cells from attack by its own complement. Although DAF expression on endothelial cells is thought to increase pathophysiologically, little is known about the natural mediators that modulate DAF expression on endothelial cells. In this study, we evaluated the effect of histamine on DAF expression on human umbilical vein cells (HUVEC). HUVEC were cultured with histamine, and DAF expression on HUVEC was determined by flow cytometry after immunostaining with a mAb to DAF. DAF expression on HUVEC was increased at 10 microM histamine, and the final level was increased time-dependently by 150% to 200% after a 24-h incubation with 100 microM histamine. The histamine-induced DAF expression was inhibited by actinomycin D and cycloheximide and accompanied by an increase in the DAF mRNA level, indicating that both transcription and translation are required. In addition, the histamine-induced DAF expression was inhibited by pyrilamine, an H1 blocker, but not by cimetidine, an H2 blocker, indicating that histamine induces the DAF expression through H1 receptors. We also demonstrated that the turnover of DAF is faster than that of MCP and CD59, and DAF is released into the culture supernatant. DAF is a glycosylphosphatidylinositol-linked protein that is released from HUVEC by a phosphatidylinositol-specific phospholipase C. Although HUVEC also contain the glycosylphosphatidylinositol-anchored complement inhibitor CD59, this was not released during a 24-h incubation, suggesting that the shedding of DAF from HUVEC is not caused by PI-PLC but by other enzymes, possibly proteinases. These results suggest that histamine, which is released from mast cells and basophils by complement-derived anaphylatoxins, increases the complement defense ability of endothelial cells by increasing their levels of DAF expression.

Programmed cell death in response to alkyllysophospholipids in endothelial cells

Addition of the alkyllysophospholipid ET16-OMe, a putative antitumor drug, to the culture medium of human vascular endothelial cells resulted in apoptotic cell death. The death was characterized as programmed cell death since the process was inhibited by the addition of an inhibitor of protein synthesis. The mechanism responsible for apoptosis induced by alkyllysophospholipid has unique characteristics, as compared to those of apoptosis induced by other antitumor drugs, since the drug caused fragmentation of dying cells and its effect could be overcome by the presence of a survival factor, namely, fibroblast growth factor.