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T Tamatani

Publications and source records attributed to T Tamatani.

At least 19 recordsLinked to original sources
PubMed2001

Effect of a mutant form of IkappaB-alpha on 5-fluorouracil-induced apoptosis in transformed human salivary gland cells.

Increasing evidence indicates that transcription factor NF-kappaB may play a role in cell survival, and that some chemotherapeutic agents activate NF-kappaB, while inhibition of NF-kappaB renders cells sensitive to these drugs. 5-Fluorouracil (5-FU) exerts its cytotoxic effect through the induction of apoptosis. However, it still remains uncertain whether 5-FU treatment in combination with the inhibition of NF-kappaB largely exerts an anti-proliferative effect on the growth of neoplastic human salivary gland cells. Thus, we investigated whether NF-kappaB suppression in transformed human salivary gland (NS-SV-AC) cells leads to a marked reduction in cell growth in response to 5-FU treatment. Our results demonstrated that under unstimulated conditions, the ability of cell growth in the super-repressor form of IkappaB-alpha (srIkappaB-alpha) cDNA-transfected cell clones (ACMT-6 and -7) was significantly lower than that in the empty vector-transfected cell clone (ACpRc-1). In addition, the growth inhibition caused by 5-FU was greatly enhanced in ACMT-6 and -7 as compared to ACpRc-1. Based on fractional inhibition analysis, this growth inhibition was due to an additive effect of both inhibitors. Electrophoretic mobility shift assay revealed that NF-kappaB activity in these cell clones was not affected by treatment with 5-FU. Accordingly, our data provide evidence that the combination of 5-FU and NF-kappaB suppression cooperatively functions in the growth inhibition of NS-SV-AC cells.

Antimetabolites, Antineoplastic↗
PubMed2000

P- and E-selectins recognize sialyl 6-sulfo Lewis X, the recently identified L-selectin ligand.

Recently we identified sialyl 6-sulfo Le(x) as a major L-selectin ligand on high endothelial venules of human peripheral lymph nodes. In this study we investigated the ligand activity of sialyl 6-sulfo Le(x) to E- and P-selectins and compared it with the binding activity of conventional sialyl Le(x), by using cultured human lymphoid cells expressing both carbohydrate determinants. The results of the recombinant selectin binding studies and the nonstatic monolayer cell adhesion assays indicated that both sialyl 6-sulfo Le(x) and conventional sialyl Le(x) served as ligand for E- and P-selectins, while L-selectin was quite specific to sialyl 6-sulfo Le(x). Anti-PSGL-1 antibodies as well as O-sialoglycoprotein endopeptidase treatment almost completely abrogated the binding of P-selectin but barely affected the binding of E-selectin, indicating that these carbohydrate determinants carried by O-glycans of PSGL-1 selectively serves as a ligand for P-selectin, while the ligand for E-selectin is not restricted to PSGL-1 nor to O-sialoglycoprotein endopeptidase-sensitive glycans. The binding of L-selectin was markedly reduced by O-sialoglycoprotein endopeptidase treatment but only minimally affected by anti-PSGL-1 antibodies, indicating that O-glycans carrying sialyl 6-sulfo Le(x) were the major L-selectin ligands, while PSGL-1 was only a minor core protein for L-selectin in these cells. These results indicated that each member of the selectin family has a distinct ligand binding specificity.

Animals↗
PubMed2000

Roles of P-selectin in inflammation, neointimal formation, and vascular remodeling in balloon-injured rat carotid arteries.

BACKGROUND: P-selectin plays key roles in mediating inflammation through promoting adherence of leukocytes to activated platelets and endothelium. This process is one of the initial events in atherosclerosis and restenosis after coronary angioplasty. METHODS AND RESULTS: Using a rat balloon-injury model, we examined the role of P-selectin in vascular inflammatory processes. In the acute phase, immunohistochemistry revealed that P-selectin was intensely expressed on both activated platelets covering the denuded segment and endothelial cells of the inflamed adventitial small vessels. Treatment with an anti-P-selectin monoclonal antibody (MAb) for 8 consecutive days significantly inhibited neointimal formation at day 14 (42% inhibition; P:<0.05), and this effect persisted at day 56 (40% inhibition; P:<0.01) compared with the control group. Vascular shrinking accompanying adventitial fibrosis was also attenuated at day 56. Inhibition of both neointimal formation and vascular shrinking resulted in the lumen area of the anti-P-selectin treatment group being approximately 3 times larger at day 56 than that of the control group. Accumulation of CD45-positive leukocytes in the developing neointima, media, and adventitia at day 8 was significantly inhibited by treatment with the anti-P-selectin MAb. Scanning electron microscopy demonstrated that anti-P-selectin treatment resulted in a less thrombogenic surface of the arterial intima, which featured a pseudoendothelial appearance at day 14 after injury. CONCLUSIONS: These results suggest that inhibition of P-selectin-mediated leukocyte recruitment prevents the development of neointimal formation, adventitial inflammation, and vascular shrinking and promotes pseudoendothelialization by luminal smooth muscle cells. This treatment thus beneficially affects vascular remodeling after balloon injury in rats.

Angioplasty, Balloon↗
PubMed2000

Identification and characterization of rat AILIM/ICOS, a novel T-cell costimulatory molecule, related to the CD28/CTLA4 family.

Activation-inducible lymphocyte immuno-mediatory molecule (AILIM) is an inducible cell surface glycoprotein expressed on thymocytes and activated lymphocytes. Specific monoclonal antibody to rat AILIM induced the cell aggregation of a rat thymoma cell line and ConA-activated splenocytes. In the present study, we identified the primary structure of two species of rat AILIM by expression cloning. We also cloned mouse and human AILIM homologues and the predicted amino acid sequences were identical to those of the inducible costimulator ICOS/CRP-1, which belongs to the CD28/CTLA4 family. Although the human and mouse AILIM/ICOS molecule is localized on T-cells, the major population of AILIM/ICOS-positive cells in rat splenocyte was CD45RA-positive B-cells. The expression level of AILIM/ICOS on T-cells was relatively low; however, its expression was drastically induced by the treatment with PMA plus Ca-ionophore or the engagement of CD3 and these costimulatory molecules. Almost all T-cells exhibited potency as to its expression. Functional analysis of AILIM/ICOS demonstrated that AILIM-mediated costimulation was relatively weak compared to that of human.

Abatacept↗
PubMed2000

5-Fluorouracil induces apoptosis through the suppression of NF-kappaB activity in human salivary gland cancer cells.

Activation of the transcription factor NF-kappaB results in protection against apoptosis, and the chemotherapeutic agent 5-Fluorouracil (5-FU) exerts its cytotoxic effect through the induction of apoptosis. Thus, we examined whether 5-FU could induce apoptosis through the suppression of NF-kappaB activity. We found that upon treatment of a human salivary gland cancer cell line (cl-1) with 5-FU, the NF-kappaB activity was suppressed in a time-dependent manner. This inhibition was mediated by a prevention of the degradation of the inhibitory IkappaB-alpha protein. In addition, the expression of TRAF-2 and cIAP-1, which are transcriptionally regulated by NF-kappaB and function as anti-apoptotic molecules through the interruption of caspase pathway, was also inhibited by 5-FU. Finally, the activity of caspase-8 and caspase-3 showed a significant increase in response to 5-FU. By flow cytometric analysis, 5-FU did not affect the expression level of Fas on the cell surface. Thus, our results suggest that one of the molecular mechanisms involved in 5-FU-induced apoptosis in cl-1 cells may be due to the suppression of NF-kappaB activity, resulting in the activation of the pro-apoptotic pathway.

Antimetabolites, Antineoplastic↗
PubMed2000

Immunoneutralization of glycoprotein Ibalpha attenuates endotoxin-induced interactions of platelets and leukocytes with rat venular endothelium in vivo.

This study aimed to examine molecular mechanisms for endotoxin-induced adhesive changes in platelets in vivo. Platelets labeled with carboxyfluorescein diacetate succinimidyl ester were visualized in rat mesenteric venules through intravital microscopy assisted by a high-speed fluorescence video imager at 1000 frames per second or by a normal-speed intensifier under monitoring of erythrocyte velocity. Leukocyte rolling was examined by normal-speed transmission video images. The velocity of platelets traveling along the centerline of venules followed that of erythrocytes, whereas that measured at the periendothelial space was significantly smaller than the erythrocyte velocity; a majority of these cells exhibited transient but notable rolling with endothelium. Administration of endotoxin increased the density of periendothelial platelets and reduced the rolling velocities of platelets and leukocytes in venules: All events were attenuated by anti-rat P-selectin monoclonal antibody s789G or by anti-human glycoprotein (GP) Ibalpha monoclonal antibody GUR83/35, which blocks ristocetin-induced aggregation of rat platelets. Isolated rat platelets injected into endotoxin-pretreated rats were able to roll on the venules. This event was attenuated by pretreatment of platelets in vitro with GUR83/35 but not with s789G, suggesting involvement of endothelial P-selectin and platelet GP Ibalpha in the endotoxin-induced responses. Furthermore, isolated human platelets showed similar rolling interactions with endotoxin-preexposed rat venules, and pretreatment of the platelets with GUR83/35, but not with s789G, significantly reduced such interactions. Our results provide the first evidence for involvement of GP Ibalpha in endotoxin-induced microvascular rolling of platelets and leukocytes, and this system serves as a potentially useful tool to examine GP Ibalpha-associated function of human platelets in vivo.

Animals↗
PubMed2000

Suppression of tumor necrosis factor alpha-induced matrix metalloproteinase 9 production by the introduction of a super-repressor form of inhibitor of nuclear factor kappaBalpha complementary DNA into immortalized human salivary gland acinar cells. Prevention of the destruction of the acinar structure in Sjögren's syndrome salivary glands.

OBJECTIVE: We have previously shown that specific enhancement in acinar cells of proteolytic activity induced by tumor necrosis factor alpha (TNFalpha) may be responsible for the destruction of the acinar structure in the salivary glands of patients with Sjögren's syndrome. Because matrix metalloproteinase 9 (MMP-9) is regulated by nuclear factor kappaB (NF-kappaB), we investigated the effect of a super-repressor form of inhibitor of nuclear factor kappaBalpha (srIkappaBalpha) on the suppression of TNFalpha-induced MMP-9 production in acinar cells. METHODS: Two srIkappaBalpha complementary DNA (cDNA)-transfected acinar cell clones (ACMT-6 and ACMT-7) and 1 empty vector-transfected cell clone (ACpRc-1) were established. After treatment of cell clones with TNFalpha, the expression of MMP-9 was examined. In addition, the effect of TNFalpha on cell growth and the morphogenetic behavior of cell clones cultured on type IV collagen-coated dishes were examined. RESULTS: TNFalpha induced the production of MMP-9 in the ACpRc-1 cell clone, but greatly suppressed MMP-9 production in ACMT-6 and ACMT-7 clones. No apparent cytotoxic effect of TNFalpha treatment was observed in these cell clones. When ACpRc-1 cells were seeded on type IV collagen-coated dishes in the presence of both TNFalpha and plasmin, type IV collagen interaction with the cells was lost and the cells entered apoptosis. However, even when ACMT-6 and ACMT-7 cells were cultured under the same culture conditions as those for ACpRc-1, these cell clones attached to the substrate and grew consistently without showing apoptosis. Conclusion. These observations indicate that suppression of TNFalpha-induced MMP-9 production by the introduction of srIkappaBalpha cDNA corrected the aberrant in vitro morphogenesis of acinar cells grown on type IV collagen.

Blotting, Western↗
PubMed2000

Expression of cutaneous lymphocyte-associated antigen regulated by a set of glycosyltransferases in human T cells: involvement of alpha1, 3-fucosyltransferase VII and beta1,4-galactosyltransferase I.

Cutaneous lymphocyte-associated antigen (CLA), which plays a key part in skin homing of human CD4+ memory T cells via CLA/E-selectin binding, is upregulated by IL-12 and downregulated by IL-4. Although alpha1,3-fucosyltransferase VII is essential for synthesis of the CLA carbohydrate epitope, little is known about how the CLA expression is regulated by a number of glycosyltransferases. A 6 wk long-term culture for the in vitro differentiation of naïve Th cells to memory Th1 cells was employed. By repeated activation in the presence of IL-12, naïve T cells differentiated into memory Th1 cells, resulting in the upregulation of CLA expression. The switching of cytokine from IL-12 to IL-4 at three cycles resulted in a marked downregulation of CLA. The transcript levels of 16 glycosyltransferases and P-selectin glycoprotein ligand-1, all considered to be potentially involved in CLA synthesis, were determined after each cycle. The level of CLA expression was well correlated with the amounts of alpha1,3-fucosyltransferase VII and beta1,4-galactosyltransferase I. Both were upregulated by IL-12 and downregulated by IL-4. In particular, alpha1,3-fucosyltransferase VII levels decreased markedly in the presence of IL-4. P-selectin glycoprotein ligand-1 and Core 2 beta1, 6-N-acetylglucosaminyltransferase were progressively up-regulated by repeated IL-12 stimulation, but they were not downregulated by IL-4. The transcript levels of some genes examined were constitutive without any correlation to CLA expression. These results suggest that the level of CLA expression is determined by alpha1, 3-fucosyltransferase VII and beta1,4-galactosyltransferase I, the other enzymes merely participating in the synthesis of CLA. In peripheral blood mononuclear cells, IL-12 and IL-4 profoundly upregulated and downregulated the alpha1,3-fucosyltransferase VII transcripts, respectively, but not the beta1,4-galactosyltransferase I ones, within only 2 h of in vitro culture. This suggested that alpha1,3-fucosyltransferase VII is transcriptionally regulated directly by IL-12 and IL-4.

Antigens, Differentiation, T-Lymphocyte↗
PubMed2000

AILIM/ICOS: a novel lymphocyte adhesion molecule.

The adhesive interaction between T cells and antigen-presenting cells is required for the formation of the immunological synapse. Inducible co-stimulator (ICOS) is a third member of the CD28 family of co-stimulatory molecules. Here we describe a novel lymphocyte adhesion molecule, of relative molecular mass 47,000, designated AILIM, that is a rat homolog of ICOS. Rat AILIM was constitutively expressed on thymocytes and was induced on naive T cells after activation. Human thymoma cells bound to purified AILIM. Furthermore, cells transfected with the AILIM gene aggregated in an AILIM-dependent manner. These results suggest a novel function for AILIM/ICOS as an adhesion molecule, which plays an important role in T cell activation.

Animals↗
PubMed2000

Effects of CTGF/Hcs24, a product of a hypertrophic chondrocyte-specific gene, on the proliferation and differentiation of chondrocytes in culture.

Recently, we cloned a messenger RNA (mRNA) predominantly expressed in chondrocytes from a human chondrosarcoma-derived chondrocytic cell line, HCS-2/8, by differential display PCR and found that its gene, named hcs24, was identical with that of connective tissue growth factor (CTGF). Here we investigated CTGF/Hcs24 function in the chondrocytic cell line HCS-2/8 and rabbit growth cartilage (RGC) cells. HCS-2/8 cells transfected with recombinant adenoviruses that generate CTGF/Hcs24 sense RNA (mRNA) proliferated more rapidly than HCS-2/8 cells transfected with control adenoviruses. HCS-2/8 cells transfected with recombinant adenoviruses that generate CTGF/Hcs24 sense RNA expressed more mRNA of aggrecan and type X collagen than the control cells. To elucidate the direct action of CTGF/Hcs24 on the cells, we transfected HeLa cells with CTGF/Hcs24 expression vectors, obtained stable transfectants, and purified recombinant CTGF/Hcs24 protein from conditioned medium of the transfectants. The recombinant CTGF/Hcs24 effectively promoted the proliferation of HCS-2/8 cells and RGC cells in a dose-dependent manner and also dose dependently increased proteoglycan synthesis in these cells. In addition, these stimulatory effects of CTGF/Hcs24 were neutralized by the addition of anti-CTGF antibodies. Furthermore, the recombinant CTGF/Hcs24 effectively increased alkaline phosphatase activity in RGC cells in culture. Moreover, RT-PCR analysis revealed that the recombinant CTGF/Hcs24 stimulated gene expression of aggrecan and collagen types II and X in RGC cells in culture. These results indicate that CTGF/Hcs24 directly promotes the proliferation and differentiation of chondrocytes.

Adenoviridae↗
PubMed2000

Serum levels of connective tissue growth factor are elevated in patients with systemic sclerosis: association with extent of skin sclerosis and severity of pulmonary fibrosis.

OBJECTIVE: To determine the serum levels and clinical correlation of connective tissue growth factors (CTGF) in patients with systemic sclerosis (SSc). METHODS: Serum samples from patients with limited cutaneous SSc (lSSc, n = 32), diffuse cutaneous SSc (dSSc, n = 28), systemic lupus erythematosus (SLE, n = 30), polymyositis/dermatomyositis (PM/DM, n = 20), and healthy control subjects (n = 30) were examined by ELISA for detection of CTGF. RESULTS: Serum CTGF levels in patients with SSc were significantly higher than those in patients with SLE or PM/DM, and in controls. CTGF levels in patients with dSSc were significantly higher than those in patients with lSSc. As for clinical correlation of CTGF, SSc patients with elevated CTGF had pulmonary fibrosis, decreased DLCO, and decreased vital capacity more frequently than those with normal CTGF levels. Further, DLCO and vital capacity were inversely and directly correlated with serum CTGF levels in patients with SSc. The dSSc patients with disease duration of 1-3 years had significantly elevated levels of CTGF compared with dSSc patients with duration < 1 year or more than 3 years. CONCLUSION: Serum CTGF levels were increased in patients with SSc, and correlated with the extent of skin sclerosis and the severity of pulmonary fibrosis. In addition, it appears that production of CTGF is involved in the development or maintenance of fibrosis rather than in initiation of fibrosis in SSc. These data suggest that CTGF plays a critical role in the development of fibrosis in SSc.

Adolescent↗
PubMed1999

Induction of heme oxygenase-1 suppresses venular leukocyte adhesion elicited by oxidative stress: role of bilirubin generated by the enzyme.

This study aimed to examine whether an elevated activity of heme oxygenase (HO)-1 in the tissue attenuates endothelial cell-leukocyte interactions microvessels in vivo. When rats were pretreated with an intraperitoneal injection of hemin, an HO-1 inducer, mesenteric tissues, including their microvessels, displayed a marked induction of HO-1 concurrent with an increase in plasma concentrations of bilirubin-IXalpha, the product of HO-catalyzed degradation of protoheme IX. In these rats, oxidative stress such as superfusion with H(2)O(2) and ischemia-reperfusion of the tissues neither induced rolling nor exhibited adherent responses of leukocytes in venules. In contrast, the oxidative stresses evoked marked rolling and adhesion of leukocytes in the control rats without HO-1 induction. The HO-1 induction also downregulated leukocyte adhesion elicited by other pro-oxidant stimuli such as N(omega)-nitro-L-arginine methyl ester. The decreases in the oxidant-elicited leukocyte adhesive responses under HO-1-inducing conditions were restored by perfusion with zinc protoporphyrin-IX, an HO inhibitor, but not with copper protoporphyrin-IX, which did not inhibit the enzyme. Furthermore, the effects of zinc protoporphyrin-IX were repressed by superfusion with bilirubin or biliverdin at the micromolar level, but not by the same concentration of carbon monoxide, another product of HO. These results indicate that induction of the HO-1 activity serves as a potential stratagem to prevent oxidant-induced microvascular leukocyte adhesion through the action of bilirubin, a product of HO reaction.

Animals↗
PubMed1999

Reconstitution of functional L-selectin ligands on a cultured human endothelial cell line by cotransfection of alpha1-->3 fucosyltransferase VII and newly cloned GlcNAcbeta:6-sulfotransferase cDNA.

Recently, we proposed sialyl 6-sulfo Lewis X as a major carbohydrate-capping group of the L-selectin ligands on high endothelial venules in human lymph nodes. In this study we succeeded in reconstituting functional L-selectin ligands on a cultured human endothelial cell line, ECV304, by transfecting the alpha1-->3fucosyltranseferase VII (Fuc-T VII) and newly cloned GlcNAcbeta:6-sulfotransferase (6-Sul-T) cDNAs. The ECV304 cells transfected with Fuc-T VII cDNA expressed conventional sialyl Lewis X detected with specific antibodies including 2H5, whereas the cells transfected with 6-Sul-T cDNA expressed sialyl 6-sulfo lactosamine as well as MECA-79-defined carbohydrate determinants, but these singly transfected cells failed to express sialyl 6-sulfo Lewis X, as detected with the antisialyl 6-sulfo Lewis X mAb G152. Sialyl 6-sulfo Lewis X appeared only on the cells that were cotransfected with both 6-Sul-T and Fuc-T VII cDNAs. Significant adhesion of L-selectin-expressing cells was seen only to the doubly transfected ECV304 cells and was inhibited by G152. No adhesion was observed to the cells transfected either with 6-Sul-T or with Fuc-T VII cDNA alone. The mRNAs of the two enzymes were expressed or were inducible upon interleukin 1 stimulation in human endothelial cells. These results indicate that a set of carbohydrate determinants synthesized by the concerted action of the two enzymes, as typically represented by the sialyl 6-sulfo Lewis X-capping group, serves as an essential component of the ligand for L-selectin and that the reagents 2H5 and MECA-79, utilized in earlier studies to detect L-selectin ligand on high endothelial venules, recognize two different aspects of the same set of synthetic products.

Antibodies, Monoclonal↗
PubMed1999

Serum IFN-inducible protein-10: a new clinical prognostic predictor of hepatocyte death in biliary atresia.

PURPOSE: The aim of this study was to determine whether chemokines such as serum IP-10 levels in patients with biliary atresia (BA) correlate with liver function and histology and assess its value as a medium to long-term prediction of prognosis in postoperative BA patients. METHODS: Thirty postoperative BA patients (mean age, 10.8+/-3.5 years) and eight normal controls (mean age, 10.3+/-3.3 years) were studied. The BA patients were divided into three groups according to liver function. Group I (n = 8) was jaundice free, had normal liver function and no evidence of severe cholangitis or portal hypertension. Group II (n = 12) had moderate liver dysfunction. Group III (n = 10), had severe liver dysfunction. Hepatic histology was assessed using conventional needle biopsy. Serum IP-10 levels were determined using a specific enzyme-linked immunosorbent assay (ELISA). RESULTS: Serum levels of IP-10 in group III (458.0+/-240.0 pg/mL) were significantly higher than those in group II (233.6+/-126.9 pg/mL; P < .0001). Levels in group II were also significantly higher than those in group I (144.8+/-23.4 pg/mL; P < .05), but there was no significant difference between group I and controls (107.9+/-34.0 pg/mL). Liver biopsy findings showed a progression of fibrosis and mononuclear cell infiltration from group I to group III. There was intimal hyperplasia and swelling of endothelial cells of branches of the hepatic artery in the portal area in group III. CONCLUSION: Because IP-10 levels correlate closely with histological findings in postoperative BA patients, it would appear to play a specific role in hepatocyte death and hepatic artery changes, thus providing important information about progressive fibrosis in BA patients that facilitates treatment decision making and prediction of prognosis.

Biliary Atresia↗
PubMed1999

Hepatocyte growth factor is an invasion/migration factor of rat urothelial carcinoma cells in vitro.

Hepatocyte growth factor (HGF) plays an important role in the growth, progression and angiogenesis of various tumors. It is reported that patients with urinary bladder cancer have elevated levels of HGF in urine and that bladder cancer tissue contains an increased amount of HGF. Thus, the data suggest a functional role of HGF in urinary bladder cancer. We evaluated the mechanistic role of HGF in urinary bladder carcinoma in vitro using the rat urothelial cell lines MYP3 (anchorage-dependent and non-tumorigenic in athymic nude mice), LMC19, MYU3L, T6 and AS-HTB1 (anchorage-independent and tumorigenic). The HGF receptor c-met was expressed by all of the cell lines, as determined by northern blot. In MYP3 cells, HGF strongly stimulated anchorage-dependent growth, but not migration, invasion or secretion of matrix metalloproteinases (MMPs). In LMC19, T6 and AS-HTB1 cells, HGF stimulated migration, invasion and secretion of MMPs. Anchorage-dependent growth stimulation was limited to AS-HTB1 cells. MYU3L cells were refractory to HGF in both growth and invasion assays. However, a neutralizing antibody and an anti-sense oligonucleotide to HGF partially inhibited the growth only of MYU3L cells, the finding being indicative of an autocrine stimulatory mechanism. HGF mRNA expression and protein synthesis were induced in bladder stromal cells by the conditioned medium of carcinoma cell lines, and IL-1beta and basic fibroblast growth factor were identified as cancer cell-derived HGF-releasing factors. These results suggest that HGF acts as a mitogen in a non-tumorigenic cell line, whereas in tumorigenic cell lines it acts as an invasion and migration factor by either a paracrine or an autocrine mechanism.

Animals↗
PubMed1999

Connective tissue growth factor induces the proliferation, migration, and tube formation of vascular endothelial cells in vitro, and angiogenesis in vivo.

Connective tissue growth factor (CTGF) is a novel cysteine-rich, secreted protein. Recently, we found that inhibition of the endogenous expression of CTGF by its antisense oligonucleotide and antisense RNA suppresses the proliferation and migration of vascular endothelial cells. In the present study, the following observations demonstrated the angiogenic function of CTGF in vitro and in vivo: (i) purified recombinant CTGF (rCTGF) promoted the adhesion, proliferation and migration of vascular endothelial cells in a dose-dependent manner under serum-free conditions, and these effects were inhibited by anti-CTGF antibodies; (ii) rCTGF markedly induced the tube formation of vascular endothelial cells, and this effect was stronger than that of basic fibroblast growth factor or vascular endothelial growth factor; (iii) application of rCTGF to the chicken chorioallantoic membrane resulted in a gross angiogenic response, and this effect was also inhibited by anti-CTGF antibodies. (iv) rCTGF injected with collagen gel into the backs of mice induced strong angiogenesis in vivo. These findings indicate that CTGF is a novel, potent angiogenesis factor which functions in multi-stages in this process.

Allantois↗
PubMed1999

Tumorigenic conversion of a rat urothelial cell line by human polymorphonuclear leukocytes activated by lipopolysaccharide.

Chronic inflammation is a significant risk factor for the development of urinary bladder cancer. We have shown that inflammation induced by killed Escherichia coli and also by its lipopolysaccharide (LPS) strikingly enhances N-methyl-N-nitrosourea (MNU)-initiated rat bladder carcinogenesis. Aspirates from the bladder lumen contained a large quantity of hydrogen peroxide (H2O2) and several cytokines. In this study, we tested the hypothesis that reactive oxygen intermediates (ROI) released from activated polymorphonuclear leukocytes (PMN) are involved in inflammation-associated bladder carcinogenesis. Using an immortalized nontumorigenic rat urothelial cell line, MYP3, we examined the effect of LPS-activated PMN on malignant transformation. MYP3 cells pretreated with or without MNU were exposed daily to LPS-activated PMN for one week and were then tested for growth in soft agar. In contrast to no colony formation by the parental cells, a varying number of colonies developed from cells treated with LPS-activated PMN. Although combined treatment with MNU and PMN was most effective (P<0.01), cells treated with LPS-activated PMN alone also formed a small number of colonies. Addition of catalase, which decomposes H2O2, and/or an antioxidant, alpha-tocopherol, reduced the number of colonies induced by LPS-activated PMN (P<0.05). Cells derived from colonies were tumorigenic in athymic nude mice. However, tumorigenicity in mice was greater with cells treated with both MNU and PMN than with cells treated with PMN alone. Our results suggest that ROI released from LPS-activated PMN may be one of the mechanisms involved in the carcinogenesis associated with active urinary tract infection.

8-Hydroxy-2'-Deoxyguanosine↗