Flavinated SDHA underlies the change in intrinsic optical properties of oral cancers

The molecular basis of reduced autofluorescence in oral squamous cell carcinoma (OSCC) cells relative to normal cells has been speculated to be due to lower levels of free flavin adenine dinucleotide (FAD). This speculation, along with differences in the intrinsic optical properties of extracellular collagen, lies at the foundation of the design of currently-used clinical optical detection devices. Here, we report that free FAD levels may not account for differences in autofluorescence of OSCC cells, but that the differences relate to FAD as a co-factor for flavination. Autofluorescence from a 70 kDa flavoprotein, succinate dehydrogenase A (SDHA), was found to be responsible for changes in optical properties within the FAD spectral region, with lower levels of flavinated SDHA in OSCC cells. Since flavinated SDHA is required for functional complexation with succinate dehydrogenase B (SDHB), decreased SDHB levels were observed in human OSCC tissue relative to normal tissues. Accordingly, the metabolism of OSCC cells was found to be significantly altered relative to normal cells, revealing vulnerabilities for both diagnosis and targeted therapy. Optimizing non-invasive tools based on optical and metabolic signatures of cancers will enable more precise and early diagnosis leading to improved outcomes in patients.

Flavinated SDHA Underlies the Change in Intrinsic Optical Properties of Oral Cancers

The molecular basis of reduced autofluorescence in oral squamous cell carcinoma (OSCC) cells relative to normal cells has been speculated to be due to lower levels of free flavin adenine dinucleotide (FAD). This speculation, along with differences in the intrinsic optical properties of extracellular collagen, lie at the foundation of the design of currently-used clinical optical detection devices. Here, we report that free FAD levels may not account for differences in autofluorescence of OSCC cells, but that the differences relate to FAD as a co-factor for flavination. Autofluorescence from a 70 kDa flavoprotein, succinate dehydrogenase A (SDHA), was found to be responsible for changes in optical properties within the FAD spectral region with lower levels of flavinated SDHA in OSCC cells. Since flavinated SDHA is required for functional complexation with succinate dehydrogenase B (SDHB), decreased SDHB levels were observed in human OSCC tissue relative to normal tissues. Accordingly, the metabolism of OSCC cells was found to be significantly altered relative to normal cells, revealing vulnerabilities for both diagnosis and targeted therapy. Optimizing non-invasive tools based on optical and metabolic signatures of cancers will enable more precise and early diagnosis leading to improved outcomes in patients.

Tranilast inhibits interleukin-1beta-induced monocyte chemoattractant protein-1 expression in rat mesangial cells

Monocyte chemoattractant protein-1 (MCP-1), a member of the CC subfamily of chemokines, plays a crucial role in the progression of glomerulonephritis by recruitment of monocytes. Tranilast, a clinically used anti-allergic drug, has been demonstrated to have various anti-inflammatory and anti-proliferative effects, and recently has been reported to prevent restenosis after percutaneous transluminal coronary angioplasty. In this study, we investigated whether tranilast inhibits MCP-1 secretion in mesangial cells. Tranilast inhibited interleukin-1beta-induced MCP-1 secretion and mRNA expression in a concentration-dependent manner. Luciferase assay showed that tranilast suppressed interleukin-1beta-induced nuclear factor-kappaB (NF-kappaB)-dependent transcription. Interleukin-1beta-induced Jun N-terminal kinase (JNK) activation was also suppressed selectively by tranilast. These results indicate that tranilast inhibits interleukin-1beta-induced MCP-1 production, at least in part, by inhibiting NF-kappaB activity and that suppression of JNK activation might be involved in the inhibition of MCP-1 production. Tranilast may serve as a new therapeutic agent for glomerulonephritis through anti-chemokine property.

[Anti-neutrophil cytoplasmic antibody--enzyme immunosorbent assay]

Enzyme immunosorbent assay(ELISA) is a very useful method to determine anti-neutrophil cytoplasmic antibody(ANCA), which is an important serological marker for pauci-immune type systemic vasculitis and necrotizing glomerulonephritis. A test was made using new myeloperoxidase(MPO)-ANCA ELISA(A), employing native MPO purified from the neutrophils in sputum as a liquid phase antigen. Furthermore, the ELISA(B) using MPO, composed of one large and one small subunit, was tested as solid phase antigen. The intra-assay and inter-assay CV of the new ELISA(A) were 3.92 to 6.75% and 5.0 to 8.1%, respectively. Close ANCA titer correlation was shown between the new MPO-ANCA ELISA(A) and the conventional ELISA, using native MPO from peripheral neutrophils as solid phase antigen. ELISA(B) showed low MPO-ANCA detection sensitivity compared to ELISA(A) and to conventional ELISA. ELISA using native MPO from neutrophils in sputum as liquid phase antigen is useful for MPO-ANCA detection. There might be an ANCA which recognizes only native form MPO.

[Estimation of age from teeth using the racemization of aspartic acid (racemization method)]

We report a method for estimation of age from teeth using the racemization of amino acids (racemization method). This method is based on the characteristics of the constant age-related increase in the amount of D-aspartic acid in dentin. We estimated age by measuring the ratio of D-aspartic acid to L-aspartic acid, i.e. the ratio of racemization ¿ratio of D/L, ln[(1 + D/L)/(1 - D/L)]¿. Because different D/L ratios have been obtained from different teeth in the same individuals and from different sites of dentin in the same tooth, we usually prepare bucco-lingual longitudinal sections at the central part of each tooth, and prepare samples of powdered whole dentin. This powder is then mixed and used to measure the D/L ratio in the dentin. To accurately estimate age from forensic specimens, we simultaneously measured the D/L ratios in more than four control teeth of the same type obtained from subjects of known age. Use of control teeth is necessary because it is sometimes difficult to maintain constant running conditions for gas chromatography to obtain reproducible values in different runs. Therefore, for every measurement, we determined an equation for calculating age from the D/L ratios of control teeth, and estimated the age of the specimen tooth by substituting in its D/L ratio. The most reliable results were obtained using samples of lower incisors or premolars, which are single-rooted teeth with a relatively small volume of dentin. Thus sampling of the dentin is easier than for other teeth. It is better to keep control teeth desiccated because racemization does not proceed readily under such conditions. The deviation from the actual age in the cases we examined was less than 3 years. Thus, racemization of amino acids can be used for accurate estimation of age from teeth.

Significance of nitric oxide and peroxynitrite in permeability changes of the retinal microvascular endothelial cell monolayer induced by vascular endothelial growth factor

Reactive oxygen species (ROS) play an important role in signaling pathways stimulated by growth factors in vascular cells. We investigated whether vascular endothelial growth factor (VEGF), which is upregulated in diabetic retinopathy and atherosclerosis, is able to enhance production of ROS, and if so, whether ROS modulate endothelial permeability. ROS levels in bovine retinal microvascular endothelial cells (BMEC) were measured by the oxidation of 2', 7'-dichlorodihydrofluorescein (DCHF), and permeability was examined by monitoring the passage of albumin through BMEC monolayers. VEGF stimulated oxidation of DCHF in BMEC, an effect which was inhibited by superoxide dismutase (SOD) and the nitric oxide (NO) synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), but not by D-NAME. Urate, a scavenger of peroxynitrite, attenuated the VEGF-induced oxidation of DCHF. VEGF elicited a significant increase in the macromolecule permeability of BMEC monolayers within 30 min. SOD did not modify the basal or the VEGF-stimulated hyperpermeability, but the combination of SOD and VEGF induced a transient reduction in permeability after 10 min. L-NAME, but not D-NAME, enhanced VEGF-induced hyperpermeability without affecting basal values. Urate did not modify the VEGF-induced changes in permeability. In conclusion, VEGF stimulates oxidation of DCHF, which most likely represents peroxynitrite formation, and induces an increase in permeability of BMEC monolayers. Activation of NO synthase seems to counteract this stimulatory effect of VEGF on endothelial permeability.

Leptin induces oxidative stress in human endothelial cells

Human umbilical vein endothelial cells (HUVEC) express functional receptors to leptin, the product of the ob gene. As human obesity is associated with atherosclerosis and hyperleptinemia, we investigated whether leptin, in addition to its angiogenic properties, exerts atherogenic effects through the generation of oxidative stress in endothelial cells. In HUVEC leptin increased the accumulation of reactive oxygen species (ROS), as assessed by the oxidation of 2', 7'- dichlorodihydrofluorescein, in a time- and concentration-dependent manner. In addition, leptin activated the NH2-terminal c-Jun kinase/stress-activated protein kinase pathway as demonstrated by enhanced JNK activity and AP-1 DNA binding. Both effects were sensitive to antioxidant treatment with N-acetylcysteine. NF-kappaB, another redox-sensitive transcription factor, was also activated by leptin stimulation in an oxidant-dependent manner. Finally, activation of both AP-1 and NF-kappaB was associated with an enhanced expression of the monocyte chemoattractant protein-1 in HUVEC. These findings demonstrate that ROS are second messengers involved in leptin-induced signaling in endothelial cells. Thus, chronic oxidative stress in endothelial cells under hyperleptinemia may activate atherogenic processes and contribute to the development of vascular pathology.

Vascular endothelial growth factor activates nuclear factor-kappaB and induces monocyte chemoattractant protein-1 in bovine retinal endothelial cells

Vascular endothelial growth factor (VEGF) has been suggested to play a role in the pathogenesis of diabetic vascular complications. In the present study, we investigated whether expression of monocyte chemoattractant protein-1 (MCP-1), a chemokine that has been proposed to recruit leukocytes to sites of inflammation, neovascularization, and vascular injury, can be modulated by VEGF in bovine retinal microvascular endothelial cells (BRECs). VEGF induced expression of MCP-1 mRNA in BRECs in a concentration- and time-dependent manner. Secretion of MCP-1 into the culture medium of BRECs treated with VEGF for 24 h was increased by 2.2-fold compared with the control. Inhibitors of transcription factor NF-kappaB, N-alpha-tosyl-L-lysine chloromethylketone (TLCK) and N-acetylcysteine (NAC), as well as an inhibitor of the extracellular signal-regulated kinase (ERK) pathway, PD 98059, attenuated VEGF-induced expression of MCP-1 mRNA. Using electrophoretic gel mobility shift assay, we observed that VEGF stimulated binding activity of NF-kappaB. VEGF-induced NF-kappaB activation was inhibited by TLCK and NAC, but not by PD 98059. Binding activity of transcription factor AP-1, which is suggested to regulate induction of the MCP-1 gene together with NF-kappaB, was also stimulated by VEGF. PD 98059 inhibited the VEGF-induced activation of AP-1. These results indicate that VEGF induces MCP-1 expression in BRECs most likely by activating NF-kappaB and AP-1 via ERK-independent and -dependent pathways. Activation of NF-kappaB and induction of MCP-1 by VEGF in microvascular endothelial cells may contribute to the development of diabetic vascular complications.

Endothelin ET(A) receptor antagonist reverses the inhibitory effect of platelet-derived growth factor on cytokine-induced nitric oxide production

Cytokines and cytokine-induced nitric oxide (NO) play important roles in inflammatory glomerular diseases, and both platelet-derived growth factor and transforming growth factor-beta inhibit cytokine-induced NO production. In this study, we demonstrated that a selective endothelin ET(A) receptor antagonist, BQ-485 (Hexahydro-1H-azepinylcarbonyl-Leu-D-Trp-D-Trp-OH), reversed the inhibitory effect of platelet-derived growth factor on cytokine-induced NO production, but not that of transforming growth factor-beta. Our findings suggest a difference between the inhibitory mechanisms of platelet-derived growth factor and transforming growth factor-beta on cytokine-induced NO production.

Glucocorticoids inhibit superoxide anion production and p22 phox mRNA expression in human aortic smooth muscle cells

-Recent reports suggest that the increased production of reactive oxygen species (ROS) in the vascular wall may contribute to the functional and structural changes associated with hypertension and atherosclerosis. Although glucocorticoid therapy can promote atherosclerosis, protective effects of these compounds on vascular lesion formation have been reported. In the present study, we investigated whether ROS production in cultured human aortic smooth muscle cells (HSMCs) can be modulated by glucocorticoids. Pretreatment of HSMCs with dexamethasone for 24 hours attenuated the basal and platelet-derived growth factor (PDGF)-AB- and angiotensin II-induced superoxide anion (O2. -) production. PDGF-AB-stimulated O2. - production was also inhibited by prednisolone and hydrocortisone but not by other steroids, such as testosterone and norgestrel. Incubation of HSMCs with glucocorticoids for 24 hours decreased 2',7'-dichlorodihydrofluorescein (DCHF) oxidation, an indicator of intracellular ROS levels. Dexamethasone decreased the mRNA expression of p22 phox, one of the components of NADPH oxidase, but had no effect on the activity of superoxide dismutase. The effects of dexamethasone on DCHF oxidation, and p22 phox mRNA expression and PDGF-AB-stimulated O2. - production were inhibited by the glucocorticoid receptor antagonist RU486. These results indicate that glucocorticoids decrease O2. - production by HSMCs via a receptor-dependent pathway. This effect is likely to be mediated by a decrease in the generating system, such as downregulation of p22 phox mRNA, rather than an increased inactivation of O2. -. The inhibition of ROS production might contribute to the local protective effects that glucocorticoids have on vascular lesion formation.

Platelet-derived growth factor-stimulated superoxide anion production modulates activation of transcription factor NF-kappaB and expression of monocyte chemoattractant protein 1 in human aortic smooth muscle cells

BACKGROUND

Platelet-derived growth factor (PDGF) and superoxide anion (O2.-) have been implicated in vascular diseases. We investigated whether PDGF stimulates the production of O2.- in human aortic smooth muscle cells (HSMCs) and whether O2.- leads in this way to the activation of nuclear factor-kappaB (NF-kappaB) and induction of monocyte chemoattractant protein 1 (MCP-1) in PDGF-stimulated HSMCs.

METHODS AND RESULTS

PDGF-AB concentration- and time-dependently stimulated O2.- generation from HSMCs. The stimulatory effect of PDGF-AB was mimicked by PDGF-BB but not by PDGF-AA. The generation of O2.- by PDGF-AB was attenuated by the NAD(P)H oxidase inhibitor iodonium diphenyl, the specific protein kinase C (PKC) inhibitor Ro 31-8220, and the phosphatidylinositol 3-kinase inhibitor wortmannin. Allopurinol and nifedipine had no effect on PDGF-AB-induced O2.- release, whereas indomethacin potentiated this response. Gel mobility shift assay revealed that PDGF-AB increased the binding activity of NF-kappaB, which contained predominantly the p50/p65 heterodimer in nuclear extracts from HSMCs. Superoxide dismutase as well as iodonium diphenyl, Ro 31-8220, and wortmannin attenuated PDGF-AB-induced activation of NF-kappaB and expression of MCP-1 mRNA. In contrast, superoxide dismutase did not inhibit the interleukin-1beta-induced NF-kappaB activation.

CONCLUSIONS

The results demonstrate that PDGF stimulates O2.- generation in HSMCs via PKC-dependent and wortmannin-sensitive pathways involving flavoenzyme(s). This PDGF-induced O2.- production may be involved in vascular lesion formation by mediating, at least in part, NF-kappaB activation and MCP-1 induction.

Endothelin-1 inhibits induction of nitric oxide synthase and GTP cyclohydrolase I in rat mesangial cells

To investigate the interaction between endothelin (ET) and the nitric oxide system, we examined the effects of ET-1 and ET-3 on the induction of inducible nitric oxide synthase (iNOS) and guanosine triphosphate cyclohydrolase I (GTP:CHI), the rate-limiting enzyme of de novo synthesis of the cofactor tetrahydrobiopterin (BH4), in rat mesangial cells. ET-1 inhibited the nitrite accumulation induced by a combination of interleukin-1 beta, tumor necrosis factor-alpha, and lipopolysaccharide in a concentration-dependent manner. The inhibitory effect of ET-3 was less potent than that of ET-1. A selective ETA antagonist, BQ-485, and an ETA and ETB antagonist, TAK-044, abolished the inhibitory effects of ET-1, whereas the selective ETB antagonist BQ-788 had no effect on the inhibition produced by ET-1. These observations indicate that ET-1 inhibits cytokine-stimulated nitrite accumulation through the ETA receptor. Western blot analysis showed that the suppression of nitrite accumulation was accompanied by a decrease in iNOS protein. Northern blot analysis showed that ET-1 inhibited the expression of both iNOS and GTP:CHI mRNA. In conclusion, ET-1 inhibits cytokine-stimulated nitric oxide production through the ETA receptor by suppressing the expression of iNOS and GTP:CHI mRNA in rat mesangial cells.

Tranilast restores cytokine-induced nitric oxide production against platelet-derived growth factor in vascular smooth muscle cells

Tranilast has been reported to reduce restenosis rate after angioplasty, but its mechanism is still unclear. We investigated the effect of tranilast against platelet-derived growth factor (PDGF) in PDGF's proliferative effect and PDGF's inhibitory effect on cytokine-induced nitric oxide (NO) production in vascular smooth muscle cells (VSMC). NO production was measured by Griess reaction. NO synthase (NOS) protein was evaluated by Western blot with monoclonal anti-rat inducible NOS antibody. A combination of interleukin-1 beta (IL-1 beta 1 ng/ml), tumor necrosis factor-alpha (TNF-alpha 2,000 U/ml), and lipopolysaccharide (100 ng/ml) significantly increased NO production and NOS protein, and tranilast significantly enhanced both in a dose-dependent manner. PDGF (100 ng/ml) significantly reduced both cytokine-induced NO production and NOS protein induction, but tranilast completely abolished these inhibitory effects. In the presence of cytokines, serum-stimulated cell proliferation was significantly inhibited by cytokine-induced NO, whereas PDGF-stimulated proliferation was not. On the other hand, tranilast not only inhibited the proliferative effect of PDGF directly, but also restored cytokine-induced NO production and its antiproliferative effect in the presence of PDGF.

Prospective study of chemoprevention of hepatocellular carcinoma with Sho-saiko-to (TJ-9)

BACKGROUND

Most hepatocellular carcinomas (HCC) arise in patients with cirrhosis, in whom its incidence is high. The prevention of HCC in patients with cirrhosis is important.

METHODS

A prospective, randomized, nonblind controlled study was performed to evaluate the preventive effect of Sho-saiko-to (TJ-9) on HCC development. TJ-9 is a Chinese herbal medicine that contains crude extracts of seven herbs; it has antitumor effects in experimental animals. Two hundred sixty patients with cirrhosis were randomly assigned to two groups, matched for age, sex, presence of hepatitis B surface antigen, and the severity of liver damage. The patients in the trial group were given TJ-9 at a daily oral dose of 7.5 g in addition to the conventional drugs given to the control patients. The patients were prospectively monitored for 60 months and the cumulative incidence of HCC and the survival rate in the two groups were calculated.

RESULTS

The cumulative incidence curve for 5 years of the trial group was lower than that of the control group (P = 0.071). For the patients without HBs antigen, the difference was significant (P = 0.024). The survival curve for 5 years of the trial group was higher than that of the control group (P = 0.053). For the patients without HBs antigen, the difference was significant (P = 0.043).

CONCLUSIONS

TJ-9 helped to prevent the development of HCC in patients with cirrhosis, particularly in patients without HBs antigen.

Prospective study of chemoprevention of hepatocellular carcinoma with Sho-saiko-to (TJ-9)

BACKGROUND

Most hepatocellular carcinomas (HCC) arise in patients with cirrhosis, in whom its incidence is high. The prevention of HCC in patients with cirrhosis is important.

METHODS

A prospective, randomized, nonblind controlled study was performed to evaluate the preventive effect of Sho-saiko-to (TJ-9) on HCC development. TJ-9 is a Chinese herbal medicine that contains crude extracts of seven herbs; it has antitumor effects in experimental animals. Two hundred sixty patients with cirrhosis were randomly assigned to two groups, matched for age, sex, presence of hepatitis B surface antigen, and the severity of liver damage. The patients in the trial group were given TJ-9 at a daily oral dose of 7.5 g in addition to the conventional drugs given to the control patients. The patients were prospectively monitored for 60 months and the cumulative incidence of HCC and the survival rate in the two groups were calculated.

RESULTS

The cumulative incidence curve for 5 years of the trial group was lower than that of the control group (P = 0.071). For the patients without HBs antigen, the difference was significant (P = 0.024). The survival curve for 5 years of the trial group was higher than that of the control group (P = 0.053). For the patients without HBs antigen, the difference was significant (P = 0.043).

CONCLUSIONS

TJ-9 helped to prevent the development of HCC in patients with cirrhosis, particularly in patients without HBs antigen.

Tranilast inhibits the effects of platelet-derived growth factor on cell proliferation and induction of nitric oxide

The effects of tranilast on DNA synthesis and cell proliferation in cultured rat mesangial cells, treated with platelet-derived growth factor (PDGF), were investigated. Tranilast significantly inhibited PDGF-stimulated DNA synthesis and cell proliferation in a dose-dependent manner. In the absence of PDGF, it also enhanced cytokine-induced nitric oxide (NO) production, PDGF significantly inhibited cytokine-induced NO production, but tranilast completely abolished this inhibitory effect of PDGF. These results show that tranilast inhibits PDGF-induced proliferation of mesangial cells under both normal and inflammatory conditions.

Prospective study of chemoprevention of hepatocellular carcinoma with Sho-saiko-to (TJ-9)

BACKGROUND

Most hepatocellular carcinomas (HCC) arise in patients with cirrhosis, in whom its incidence is high. The prevention of HCC in patients with cirrhosis is important.

METHODS

A prospective, randomized, nonblind controlled study was performed to evaluate the preventive effect of Sho-saiko-to (TJ-9) on HCC development. TJ-9 is a Chinese herbal medicine that contains crude extracts of seven herbs; it has antitumor effects in experimental animals. Two hundred sixty patients with cirrhosis were randomly assigned to two groups, matched for age, sex, presence of hepatitis B surface antigen, and the severity of liver damage. The patients in the trial group were given TJ-9 at a daily oral dose of 7.5 g in addition to the conventional drugs given to the control patients. The patients were prospectively monitored for 60 months and the cumulative incidence of HCC and the survival rate in the two groups were calculated.

RESULTS

The cumulative incidence curve for 5 years of the trial group was lower than that of the control group (P = 0.071). For the patients without HBs antigen, the difference was significant (P = 0.024). The survival curve for 5 years of the trial group was higher than that of the control group (P = 0.053). For the patients without HBs antigen, the difference was significant (P = 0.043).

CONCLUSIONS

TJ-9 helped to prevent the development of HCC in patients with cirrhosis, particularly in patients without HBs antigen.

Natriuretic peptide-augmented induction of nitric oxide synthase through cyclic guanosine 3',5'-monophosphate elevation in vascular smooth muscle cells

To elucidate the role of natriuretic peptides in vascular remodeling, the effects of atrial natriuretic peptide, brain natriuretic peptide, and C-type natriuretic peptide (CNP) on the induction of inducible nitric oxide (NO) synthase (iNOS) in rat aortic smooth muscle cells were examined. Although none of the peptides when applied alone induced the production of nitrite, a stable end product of NO, each peptide dramatically enhanced nitrite production induced by a cytokine combination of interleukin-1 alpha and tumor necrosis factor-alpha. Each natriuretic peptide stimulated intracellular cGMP accumulation in a dose-dependent manner. Time-dependent nitrite production by the cytokines was increased by CNP cotreatment and inhibited by NG-methyl-L-arginine, indicating involvement of the L-arginine-NO pathway. Northern blot analysis showed that the augmented nitrite production was accompanied by an increase in iNOS messenger RNA. A cGMP analog, 8-bromo-cGMP, completely mimicked all of the effects of CNP described above. A cGMP-dependent protein kinase inhibitor, KT5823, paradoxically increased nitrite production and iNOS messenger RNA levels induced by the combination of 8-bromo-cGMP and both cytokines or by the two cytokines only. These data demonstrate the stimulatory effect of cGMP on cytokine-induced iNOS and imply that natriuretic peptides may play a regulatory role in vascular remodeling via the production of large amounts of NO.

Cyclosporin A inhibits nitric oxide synthase induction in vascular smooth muscle cells

The effect of cyclosporin A on induction of nitric oxide synthase in rat aortic smooth muscle cells was examined. A combination of interleukin-1 alpha (100 U/mL) and tumor necrosis factor--alpha (5000 U/mL) induced accumulation of nitrite/nitrate, the stable end products of nitric oxide, in culture media within 48 hours. Cyclosporin A inhibited this nitrite/nitrate accumulation in a concentration-dependent manner with an IC50 of 4 x 10(-7) mol/L when applied simultaneously with the cytokines. The expression of inducible nitric oxide synthase messenger RNA (mRNA) induced by the combination of interleukin-1 alpha and tumor necrosis factor-alpha was inhibited by the cyclosporin A cotreatment. Cyclosporin A did not decrease inducible nitric oxide synthase mRNA stability in the presence of transcription inhibitor actinomycin D (5 micrograms/mL). Induction of nitrite/nitrate production by the combination of tumor necrosis factor-alpha and bacterial lipopolysaccharide or that of interleukin-1 alpha and interferon gamma (100 U/mL) was also inhibited by cyclosporin A cotreatment. Another inhibitor of calcineurin, FK506 (up to 10(-6) mol/L), had no effect on the induction of nitrite/nitrate production, suggesting the possibility that the inhibitory effect of cyclosporin A may be exerted by means of a novel pathway other than inhibition of calcineurin. These results indicate that cyclosporin A inhibits inducible nitric oxide synthase induction at the mRNA level and that inducible nitric oxide synthase in vascular smooth muscle cells can be a target for cyclosporin A, providing a possible mechanism for the interference of the drug with the balance of vasoactive substances.

Up-regulation of nitric oxide synthase by estradiol in human aortic endothelial cells

We have examined the effects of sex hormones on calcium-dependent NO production and protein levels of NO synthase in cultured human aortic endothelial cells, which were treated with various doses of 17 beta-estradiol and testosterone for 8-48 h. Treatment with 17 beta-estradiol enhanced calcium-dependent NO production, but testosterone had exerted no effect. Western blot using monoclonal anti-human endothelial NO synthase antibody clarified that increased NO production by 17 beta-estradiol treatment was accompanied by increased NO synthase protein. Our results provide evidence that human endothelial NO synthase can be regulated by estrogens.

Pressure enhances endothelin-1 release from cultured human endothelial cells

The effect of pure pressure without shear stress or stretch on the release of endothelin-1 was investigated. Elevation of pressure significantly enhanced endothelin-1 release from cultured human umbilical vein endothelial cells. A calcium channel blocker, nifedipine, and a putative stretch-activated channel blocker, gadolinium, did not affect the pressure-induced endothelin-1 increase. On the other hand, a phospholipase C inhibitor, 2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate, and protein kinase C inhibitors, 1-5-(isoquinolinylsulfonyl)-2-methylpiperazine and chelerythrine, significantly inhibited the pressure-induced endothelin-1 increase. Moreover, pure pressure reduced basal nitric oxide release, while pretreatment with a nitric oxide synthase inhibitor, NG-monomethyl-L-arginine, had no effect on the pressure-induced endothelin-1 increase. In conclusion, our results show for the first time that pressure enhances endothelin-1 release partially through activation of phospholipase C and protein kinase.

Pressure promotes DNA synthesis in rat cultured vascular smooth muscle cells

High blood pressure is one of the major risk factors for atherosclerosis. In this study, we examined the effects of pressure on cell proliferation and DNA synthesis in cultured rat vascular smooth muscle cells. Pressure without shear stress and stretch promotes cell proliferation and DNA synthesis in a pressure-dependent manner. Pressure-induced DNA synthesis was inhibited significantly by the phospholipase C (PLC) inhibitor 2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate, the protein kinase C inhibitor H-7, 1-(5-isoquinolinylsulfonyl)-2-methyl-piperazine, staurosporine, and the tyrosine kinase inhibitor ([3,4,5-trihydroxyphenyl]methylene)propanedinitrile. To clarify whether activation of PLC and calcium mobilization are involved in pressure-induced DNA synthesis, production of 1,4,5-inositol trisphosphate (IP3) and intracellular Ca2+ was measured. Pure pressure increased IP3 and intracellular Ca2+ in a pressure-dependent manner. The increases in both IP3 and intracellular Ca2+ were inhibited significantly by 2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate. This study demonstrates a novel cellular mechanism whereby pressure regulates DNA synthesis in vascular smooth muscle cells, possibly via activation of PLC and protein kinase C.

Dexamethasone inhibits nitric oxide synthase mRNA induction by interleukin-1 alpha and tumor necrosis factor-alpha in vascular smooth muscle cells

The effects of interleukin-1 alpha, tumor necrosis factor-alpha and dexamethasone on the induction of nitric oxide synthase mRNA in rat aortic smooth muscle cells were studied. Neither interleukin-1 alpha (up to 100 U/ml) nor tumor necrosis factor-alpha (up to 5000 U/ml) was capable of inducing nitrite/nitrate production and nitric oxide synthase mRNA in smooth muscle cells. In contrast, treatment for 12 hr or longer with a combination of the two synergistically induced nitrite/nitrate and cyclic GMP production in cell culture media and nitric oxide synthase mRNA, both of which were prevented by dexamethasone. Contamination with bacterial lipopolysaccharide, which may affect the induction of nitric oxide synthase, was below 30 pg/ml in all experiments. Our findings show that dexamethasone and these cytokines regulate the induction of nitric oxide synthase at the mRNA level in vascular smooth muscle cells.

Nitric oxide synthase mRNA in endothelial cells: synergistic induction by interferon-gamma, tumor necrosis factor-alpha and lipopolysaccharide and inhibition by dexamethasone

Regulation of nitric oxide synthase mRNA by interferon-gamma, tumor necrosis factor-alpha, bacterial lipopolysaccharide (LPS) and dexamethasone in rat aortic endothelial cells was examined. The combination of interferon-gamma (100 U/ml) and tumor necrosis factor-alpha (5000 U/ml) evoked a time-dependent increase in nitric oxide synthase mRNA and nitrite/nitrate production, both of which were inhibited by dexamethasone. Neither interferon-gamma (100 U/ml), tumor necrosis factor-alpha (5000 U/ml) nor LPS (100 ng/ml) alone was capable of increasing nitric oxide synthase mRNA and nitrite/nitrate production in these cells. However, combinations of two of the three agents synergistically increased both nitric oxide synthase mRNA and nitrite/nitrate production. When the three agents were applied simultaneously, nitric oxide synthase mRNA and nitrite/nitrate production were both markedly increased. LPS contamination, which may affect the induction of nitric oxide synthase, was below 20 pg/ml in all experiments unless LPS was added exogenously, namely, the effects observed were those of the cytokines themselves. Our results suggest that in endothelial cells, these cytokines regulate the production of nitric oxide at the level of nitric oxide synthase mRNA induction.

[Age estimation by amino acid racemization in dentin--application of fractionation and extraction]

This study was made to improve the validity of age estimation from teeth using amino acid racemization. The correlation between actual age and the D/L ratio of aspartic acid was investigated by analyzing not only total amino acid but its fractionated substances, insoluble collagen and soluble peptide. The coefficient values of correlation between the D/L ratio and actual age in lower central incisors were 0.996 (sigma = 1.0 years) for total amino acid, 0.998 (sigma = +/- 1.8 years) for insoluble collagen, and 0.997 (sigma = +/- 0.9 years) for soluble peptide. The corresponding figures in upper and lower first premolars were 0.991 (sigma = +/- 1.6 years), 0.989 (sigma = +/- 1.9 years), and 0.994 (sigma = +/- 1.4 years), respectively. The reactive velocity of aspartic acid racemization was highest for soluble peptide both in lower central incisors and upper and lower first premolars, approximately three times as rapid as that for total amino acid. The velocity for insoluble collagen was slightly lower than that for total amino acid. Age estimation was attempted from the teeth of an unknown body. As a result, age estimated from the analysis of soluble peptide was most accurate. These results suggest that the analysis not only of total amino acid in dentin but its fractionated and extracted substances can lead to higher reliability in age estimation. Soluble peptide, in particular, has been found to be most effective.

[Two cases of age estimation from teeth of burned body using amino acid racemization]

Age estimation of 2 bodies were attempted, using the D/L ratio of aspartic acid in teeth. In case one, the oral cavity had been exposed to air with protruded anterior teeth. Seventeen teeth were extracted and put to examination. From anterior , especially those with darkly incinerated surfaces, estimated ages were far advanced than the actual one. However, from molars whose surfaces were similar in appearance to those of the living teeth, estimations of +/- 3 years error were achieved. In case two, the oral cavity had been closed, stuffed with the tongue and no teeth had been exposed. In all the 15 teeth examined, age estimations of +/- 3 years were achieved. This leads us to conclude that as for the teeth from a burned body, the method of age estimation through racemization is quite possible and valid, provided that the surfaces of the teeth maintained the tint of the living teeth.

A comparison of transcatheter arterial embolization with one shot therapy for the patients with hepatic cell carcinoma

It has been confirmed gradually that transcatheter arterial embolization is the most effective, conservative therapy for the treatment of unresectable hepatic cell carcinoma (hepatoma). Embolization or one shot therapy was carried out in a clinical trial involving 41 patients with unresectable hepatoma visiting our department. Embolization group (emboli G): 19 cases. 1 to 6 embolizations in each case. One shot group (one shot G): 22 cases. Medications: Mitomycin C 10-40 mg and others. Disappearance rate of icterus after treatment was 50% (emboli G) and 25% (one shot G). Decrease in size of hepatomegaly or tumor was seen in 84% (emboli G) and 32% (one shot G) which was statistically significant (less than 1%). Serum AFP titer after embolization decreased in all cases but in only 5 of 12 cases (ca 41%) after one shot (less than 1%). Effective cases measured by Karnofsky's method were 18 out of 19 cases (95%) in emboli G, but in one shot G only 10 out of 22 cases (ca 45%)(less than 0.1%). Survival rate after each therapy was 67% (emboli G) and 38% (one shot G) after 6 months, and 59% (emboli G) and 19% (one shot G) at 1 year respectively. One study showed that transcatheter arterial embolization therapy was much more effective than one shot therapy.