Hydrogen peroxide is an endothelium-derived hyperpolarizing factor in mice

The endothelium plays an important role in maintaining vascular homeostasis by synthesizing and releasing several endothelium-derived relaxing factors, such as prostacyclin, nitric oxide (NO), and the previously unidentified endothelium-derived hyperpolarizing factor (EDHF). In this study, we examined our hypothesis that hydrogen peroxide (H(2)O(2)) derived from endothelial NO synthase (eNOS) is an EDHF. EDHF-mediated relaxation and hyperpolarization in response to acetylcholine (ACh) were markedly attenuated in small mesenteric arteries from eNOS knockout (eNOS-KO) mice. In the eNOS-KO mice, vasodilating and hyperpolarizing responses of vascular smooth muscle per se were fairly well preserved, as was the increase in intracellular calcium in endothelial cells in response to ACh. Antihypertensive treatment with hydralazine failed to improve the EDHF-mediated relaxation. Catalase, which dismutates H(2)O(2) to form water and oxygen, inhibited EDHF-mediated relaxation and hyperpolarization, but it did not affect endothelium-independent relaxation following treatment with the K(+) channel opener levcromakalim. Exogenous H(2)O(2) elicited similar relaxation and hyperpolarization in endothelium-stripped arteries. Finally, laser confocal microscopic examination with peroxide-sensitive fluorescence dye demonstrated that the endothelium produced H(2)O(2) upon stimulation by ACh and that the H(2)O(2) production was markedly reduced in eNOS-KO mice. These results indicate that H(2)O(2) is an EDHF in mouse small mesenteric arteries and that eNOS is a major source of the reactive oxygen species.

Mouse Gli1 mutants are viable but have defects in SHH signaling in combination with a Gli2 mutation

The secreted factor Sonic hedgehog (SHH) is both required for and sufficient to induce multiple developmental processes, including ventralization of the CNS, branching morphogenesis of the lungs and anteroposterior patterning of the limbs. Based on analogy to the Drosophila Hh pathway, the multiple GLI transcription factors in vertebrates are likely to both transduce SHH signaling and repress Shh transcription. In order to discriminate between overlapping versus unique requirements for the three Gli genes in mice, we have produced a Gli1 mutant and analyzed the phenotypes of Gli1/Gli2 and Gli1/3 double mutants. Gli3(xt) mutants have polydactyly and dorsal CNS defects associated with ectopic Shh expression, indicating GLI3 plays a role in repressing Shh. In contrast, Gli2 mutants have five digits, but lack a floorplate, indicating that it is required to transduce SHH signaling in some tissues. Remarkably, mice homozygous for a Gli1(zfd)mutation that deletes the exons encoding the DNA-binding domain are viable and appear normal. Transgenic mice expressing a GLI1 protein lacking the zinc fingers can not induce SHH targets in the dorsal brain, indicating that the Gli1(zfd)allele contains a hypomorphic or null mutation. Interestingly, Gli1(zfd/zfd);Gli2(zfd/+), but not Gli1(zfd/zfd);Gli3(zfd/+) double mutants have a severe phenotype; most Gli1(zfd/zfd);Gli2(zfd/+) mice die soon after birth and all have multiple defects including a variable loss of ventral spinal cord cells and smaller lungs that are similar to, but less extreme than, Gli2(zfd/zfd) mutants. Gli1/Gli2 double homozygous mutants have more extreme CNS and lung defects than Gli1(zfd/zfd);Gli2(zfd/+) mutants, however, in contrast to Shh mutants, ventrolateral neurons develop in the CNS and the limbs have 5 digits with an extra postaxial nubbin. These studies demonstrate that the zinc-finger DNA-binding domain of GLI1 protein is not required for SHH signaling in mouse. Furthermore, Gli1 and Gli2, but not Gli1 and Gli3, have extensive overlapping functions that are likely downstream of SHH signaling.

Efficacy and safety of recombinant human soluble thrombomodulin (ART-123) in disseminated intravascular coagulation: results of a phase III, randomized, double-blind clinical trial

BACKGROUND

Soluble thrombomodulin is a promising therapeutic natural anticoagulant that is comparable to antithrombin, tissue factor pathway inhibitor and activated protein C.

OBJECTIVES

We conducted a multicenter, double-blind, randomized, parallel-group trial to compare the efficacy and safety of recombinant human soluble thrombomodulin (ART-123) to those of low-dose heparin for the treatment of disseminated intravascular coagulation (DIC) associated with hematologic malignancy or infection.

METHODS

DIC patients (n = 234) were assigned to receive ART-123 (0.06 mg kg(-1) for 30 min, once daily) or heparin sodium (8 U kg(-1) h(-1) for 24 h) for 6 days, using a double-dummy method. The primary efficacy endpoint was DIC resolution rate. The secondary endpoints included clinical course of bleeding symptoms and mortality rate at 28 days.

RESULTS

DIC was resolved in 66.1% of the ART-123 group, as compared with 49.9% of the heparin group [difference 16.2%; 95% confidence interval (CI) 3.3-29.1]. Patients in the ART-123 group also showed more marked improvement in clinical course of bleeding symptoms (P = 0.0271). The incidence of bleeding-related adverse events up to 7 days after the start of infusion was lower in the ART-123 group than in the heparin group (43.1% vs. 56.5%, P = 0.0487).

CONCLUSIONS

When compared with heparin therapy, ART-123 therapy more significantly improves DIC and alleviates bleeding symptoms in DIC patients.

Dentin Regeneration by Dental Pulp Stem Cell Therapy with Recombinant Human Bone Morphogenetic Protein 2

Regenerative medicine is based on stem cells, signals, and scaffolds. Dental pulp tissue has the potential to regenerate dentin in response to noxious stimuli, such as caries. The progenitor/stem cells are responsible for this regeneration. Thus, stem cell therapy has considerable promise in dentin regeneration. Culture of porcine pulp cells, as a three-dimensional pellet, promoted odontoblast differentiation compared with monolayers. The expression of dentin sialophosphoprotein (Dspp) and enamelysin/matrix metalloproteinase 20 (MMP20) mRNA confirmed the differentiation of pulp cells into odontoblasts and was stimulated by the morphogenetic signal, bone morphogenetic protein 2 (BMP2). Based on the in vitro experiments, an in vivo evaluation of pulp progenitor/stem cells in the dog was performed. The autogenous transplantation of the BMP2-treated pellet culture onto the amputated pulp stimulated reparative dentin formation. In conclusion, BMP2 can direct pulp progenitor/stem cell differentiation into odontoblasts and result in dentin formation.

Pituitary tumor transforming gene (PTTG) expression in pituitary adenomas

We recently cloned a novel pituitary tumor transforming gene (PTTG). Here we report PTTG expression in human pituitary adenomas and in normal pituitary tissue. In situ hybridization revealed PTTG expression in nonfunctioning and in GH-secreting adenomas but not in normal pituitary tissue. Using a more sensitive detection method, RT-PCR, low level PTTG expression was detected in normal pituitary. However, when expression levels in normal pituitary tissue were compared with those in 54 pituitary tumors using comparative reverse transcription polymerase chain reaction (RT-PCR), we found that most tumor samples expressed higher levels of PTTG. More than 50% PTTG increases were observed in 23 of 30 nonfunctioning pituitary tumors, all 13 GH-producing tumors, 9 of 10 prolactinomas, and 1 ACTH-secreting tumor, with more than 10-fold increases evident in some tumors. Furthermore, higher PTTG expression (P = 0.03) was observed in hormone-secreting tumors that had invaded the sphenoid bone (stages III and IV; 95% CI 3.118-9.715) compared with hormone-secreting tumors that were confined to the pituitary fossa (stages I and II; 95% CI 1.681-3.051). Therefore, PTTG abundance is a molecular marker for invasiveness in hormone-secreting pituitary tumors. The ubiquitous and prevalent expression of pituitary adenoma PTTG suggests that PTTG plays a role in pituitary tumorigenesis and invasiveness.

Importance of endothelium-derived hyperpolarizing factor in human arteries

The endothelium plays an important role in maintaining the vascular homeostasis by releasing vasodilator substances, including prostacyclin (PGI2), nitric oxide (NO), and endothelium-derived hyperpolarizing factor (EDHF). Although the former two substances have been investigated extensively, the importance of EDHF still remains unclear, especially in human arteries. Thus we tested our hypothesis that EDHF plays an important role in human arteries, particularly with reference to the effect of vessel size, its vasodilating mechanism, and the influences of risk factors for atherosclerosis. Isometric tension and membrane potentials were recorded in isolated human gastroepiploic arteries and distal microvessels (100-150 microm in diameter). The contribution of PGI2, NO, and EDHF to endothelium-dependent relaxations was analyzed by inhibitory effects of indomethacin, NG-nitro- L-arginine, and KCl, respectively. The nature of and hyperpolarizing mechanism by EDHF were examined by the inhibitory effects of inhibitors of cytochrome P450 pathway and of various K channels. The effects of atherosclerosis risk factors on EDHF-mediated relaxations were also analyzed. The results showed that (a) the contribution of EDHF to endothelium-dependent relaxations is significantly larger in microvessels than in large arteries; (b) the nature of EDHF may not be a product of cytochrome P450 pathway, while EDHF-induced hyperpolarization is partially mediated by calcium-activated K channels; and (c) aging and hypercholesterolemia significantly impair EDHF-mediated relaxations. These results demonstrate that EDHF also plays an important role in human arteries.

Analyses of the factors influencing bone graft infection after delayed cranioplasty

BACKGROUND

Several factors influencing bone graft infection after delayed cranioplasty are analyzed in order to reduce the occurrence of infection.

METHODS

For about 10 years, from March 1995 to February 2005, delayed cranioplasty was performed for 206 cases. The cases comprised 124 males and 82 females. Age distribution of the patients ranged from 6 months to 79 years old. The mean postoperative follow-up period was 1834 days. Autogenous bone, which was preserved in 100% ethanol at -20 degrees C and autoclaved before operation, was used in 54 patients. Polymethylmethacrylate (PMMA) was used in 55 patients. Custom-made PMMA was used in 3 patients. Custom-made titanium mesh was used in 77 patients. Custom-made ceramics (Alumina-ceramics 10 cases and hydroxyapatite 7 cases) was used in 17 patients.

FINDINGS

Autoclaved and autogenous bone graft and PMMA have a significantly high rate of graft infection. Titanium mesh has the significantly lowest rate of graft infection. Alumina-ceramic has a merit that it has sufficient strength, however the number of cases using custom-made ceramics including alumina-ceramic was relatively small, and thus we cannot find significant differences in infection rate compared with that of other materials. There was no statistically significant difference in the bone graft infection rate among four categories of preceding diseases; cerebrovascular diseases, head trauma, infectious diseases, and brain tumour.

CONCLUSION

Autoclaved and autogenous bone grafts and PMMA have a significantly higher rate of graft infection. Titanium mesh has the significantly lowest rate of graft infection.

Regulatory role of transforming growth factor-beta, bone morphogenetic protein-2, and protein-4 on gene expression of extracellular matrix proteins and differentiation of dental pulp cells

The expression of developmental stage-specific genes during pulp cell differentiation into preodontoblasts was examined in bovine adult pulp cell culture. When proliferation was down-regulated after 14 days of primary culture, expression of fibronectin and type I and type III collagen mRNAs was increased. Expression of alkaline phosphatase was gradually increased, and mRNA for osteocalcin, a marker of preodontoblast, appeared just before the onset of mineralization. Contrarily, in expanded culture, the expression of mRNA for the extracellular matrix proteins was gradually increased from the beginning of culture up to Day 28. Similarly, mRNA levels of alkaline phosphatase and osteocalcin were also increased gradually. Expression of TGF-beta 1 mRNA disappeared on Day 21 in the primary culture when expression of alkaline phosphatase mRNA was increased. BMP-4 mRNA was expressed on Day 14 when the expression of the extracellular matrix proteins was increased. BMP-2 mRNA was expressed on Day 28 when osteocalcin appeared. Recombinant TGF-beta 1 inhibited alkaline phosphatase activity, while BMP-2 and BMP-4 stimulated it. BMP-4 increased expression of alpha 1(I) collagen mRNA, and BMP-2 increased osteocalcin synthesis. These results demonstrate the regulatory role of these TGF-beta superfamily members on the gene expression of extracellular matrix proteins and the differentiation of pulp cells into preodontoblasts.

Induction of dentin formation on canine amputated pulp by recombinant human bone morphogenetic proteins (BMP)-2 and -4

Dental pulp cells have the potential to differentiate into odontoblasts. The molecular mechanisms underlying differentiation are not clear. Demineralized dentin matrix is osteoinductive and contains bone morphogenetic protein (BMP) activity. BMPs have been implicated in embryonic odontogenic differentiation and hence may play a role in the differentiation of adult pulp cells into odontoblasts during pulpal healing. This study examined the hypothesis that BMPs induce dentin formation on amputated canine pulp. Recombinant human BMP-2 and BMP-4 were capped with inactivated dentin matrix on amputated pulp. At two months, the amputated pulp was filled with tubular dentin in the lower part and osteodentin in the upper part. The amount of dentin formed was markedly diminished when dentin matrix alone was implanted. These findings imply that recombinant human BMP-2 and BMP-4 induce differentiation of adult pulp cells into odontoblasts. Thus, BMPs may have a role in dentistry as a bioactive pulp-capping agent to induce dentin formation.

Structure, expression, and function of human pituitary tumor-transforming gene (PTTG)

Despite advances in characterizing the pathophysiology and genetics of pituitary tumors, molecular mechanisms of their pathogenesis are poorly understood. Recently, we isolated a transforming gene [pituitary tumor-transforming gene (PTTG)] from rat pituitary tumor cells. Here we describe the cloning of human PTTG, which is located on chromosome 5q33 and shares striking sequence homology with its rat counterpart. Northern analysis revealed PTTG expression in normal adult testis, thymus, colon, small intestine, brain, lung, and fetal liver, but most abundant levels of PTTG mRNA were observed in several carcinoma cell lines. Stable transfection of NIH 3T3 cells with human PTTG cDNA caused anchorage-independent transformation in vitro and induced in vivo tumor formation when transfectants were injected into athymic mice. Overexpression of PTTG in transfected NIH 3T3 cells also stimulated expression and secretion of basic fibroblast growth factor, a human pituitary tumor growth-regulating factor. A proline-rich region, which contains two PXXP motifs for the SH3 domain-binding site, was detected in the PTTG protein sequence. When these proline residues were changed by site-directed mutagenesis, PTTG in vitro transforming and in vivo tumor-inducing activity, as well as stimulation of basic fibroblast growth factor, was abrogated. These results indicate that human PTTG, a novel oncogene, may function through SH3-mediated signal transduction pathways and activation of growth factor(s).

Expression of growth/differentiation factor 11, a new member of the BMP/TGFbeta superfamily during mouse embryogenesis

We have cloned and characterized a new member of the bone morphogenetic protein/transforming growth factor beta (BMP/TGFbeta) superfamily, growth differentiation factor 11 (Gdf11), from rat incisor pulp RNA by reverse transcription-polymerase chain reaction using degenerate primers. The mature carboxyl-terminal domain encoded by Gdf11 is most closely related to Gdf8, being 90% identical to the mouse gene. Northern blot analysis revealed Gdf11 is expressed in adult dental pulp and brain. In situ hybridization of sections and whole-mount embryos demonstrated Gdf11 is first strongly expressed in restricted domains at 8.5 days post coitus (dpc) when it is highest in the tail bud. At 10.5 dpc, it is expressed in the branchial arches, limb bud, tail bud and posterior dorsal neural tube. Later, it is expressed in terminally-differentiated odontoblasts, the nasal epithelium, retina and specific regions of the brain.

Endothelium-dependent hyperpolarization caused by bradykinin in human coronary arteries

The present study was designed to determine whether bradykinin induces endothelium-dependent hyperpolarization of vascular smooth muscle in human coronary arteries, and if so, to define the contribution of this hyperpolarization to endothelium-dependent relaxations. The membrane potential of arterial smooth muscle cells (measured by glass microelectrodes) and changes in isometric force were recorded in tissues from six patients undergoing heart transplantation. In the presence of indomethacin and NG-nitro-L-arginine (NLA), the membrane potential was -48.3 +/- 0.6 and -46.9 +/- 0.6 mV, in preparations with and without endothelium, respectively, and was not affected by treatment with perindoprilat, an angiotensin-converting enzyme inhibitor. In the presence of both indomethacin and NLA, bradykinin evoked transient and concentration-dependent hyperpolarizations only in tissues with endothelium, which were augmented by perindoprilat and mimicked by the calcium ionophore A23187. Glibenclamide did not inhibit membrane hyperpolarization to bradykinin. In rings contracted with prostaglandin F2 alpha, the cumulative addition of bradykinin caused a concentration-dependent relaxation during contractions evoked by prostaglandin F2 alpha, which was not abolished by NLA and indomethacin. The present findings demonstrate the occurrence of endothelium-dependent hyperpolarization, and its contribution to endothelium-dependent relaxations, in the human coronary artery.

Inhibition of cell growth and induction of apoptotic cell death by the human tumor-associated antigen RCAS1

Tumor-associated antigens that can be recognized by the immune system include the MAGE-family, p53, MUC-1, HER2/neu and p21ras. Despite their expression of these distinct antigens, tumor elimination by the immune system is often inefficient. Postulated mechanisms include insufficient expression of co-stimulatory or adhesion molecules by tumor cells, or defective processing and presentation of antigens on their cell surfaces. Tumor cells may also evade immune attack by expressing CD95 (APO-1/Fas) ligand or other molecules that induce apoptosis in activated T cells. Here we describe RCAS1 (receptor-binding cancer antigen expressed on SiSo cells), a membrane molecule expressed on human cancer cells. RCAS1 acts as a ligand for a putative receptor present on various human cell lines and normal peripheral lymphocytes such as T, B and NK cells. The receptor expression was enhanced by activation of the lymphocytes. RCAS1 inhibited the in vitro growth of receptor-expressing cells and induced apoptotic cell death. Given these results, tumor cells may evade immune surveillance by expression of RCAS1, which would suppress clonal expansion and induce apoptosis in RCAS1 receptor-positive immune cells.

Angiotensin I-converting enzyme inhibitory peptides in an alkaline protease hydrolyzate derived from sardine muscle

The ACE inhibitory activity of an alkaline protease hydrolyzate from sardine muscle did not change after being treated by gastrointestinal proteases (IC50 = 0.082 mg protein/ml). Eleven new ACE inhibitory peptides, constructed with 2 to 4 amino acid residues, were isolated from the hydrolyzate. The ACE inhibitory activity of each was mostly below 100 microM of IC50 value; the maximal inhibitory activity was observed for Lys-Trp (IC50 = 1.63 microM). The isolated peptides inhibited ACE competitively, except for Met-Tyr with non-competitive inhibition. As the result of sequence homology, Arg-Val-Tyr isolated from the hydrolyzate was found in the primary structure of angiotensins I, II, and III, and of des As[1]-angiotensin I.

Expression of pituitary-tumour transforming gene in colorectal tumours

BACKGROUND

Basic fibroblast growth factor promotes angiogenesis and mitogenesis in colon carcinomas. Pituitary-tumour transforming gene (PTTG1) causes in-vitro and in-vivo transformation, regulates secretion of basic fibroblast growth factor, and inhibits chromatid separation. Most normal tissues show little or no PTTG1 expression but cancer cells express the gene abundantly. We postulated that PTTG1 expression in colorectal tumours is related to tumour invasiveness.

METHODS

PTTG1 gene and protein expression were assessed in 68 colorectal tumours and compared with invasive characteristics, such as lymph-node invasion, evidence of metastases, tumour vessel density, and expression of basic fibroblast growth factor. PTTG1 expression is given in terms of the fold-increase over that in normal-adjacent colorectal tissue.

FINDINGS

PTTG1 was overexpressed in all of 48 colon carcinomas (median fold-increase 2.2 [IQR 1.8-3.3]) and in 19 of 20 colonic polyps (2.2 [1.6-3.1]) compared with normal colonic tissue. Invasion of surrounding lymph nodes was associated with higher PTTG1 expression than in carcinomas limited to the bowel wall (3.4 [2.1-5.9] vs 1.9 [1.7-2.4], p=0.007), and higher PTTG1 expression was seen in more vascular than in less vascular tumours (2.6 [1.9-5.1] vs 1.9 [1.8-2.5], p=0.04).

INTERPRETATION

Increased tumour PTTG1 expression may be a marker of invasive colorectal carcinoma and could represent a new therapeutic target.

Impact of the Clinical Frailty Scale on Outcomes After Transcatheter Aortic Valve Replacement

Background:

The semiquantitative Clinical Frailty Scale (CFS) is a simple tool to assess patients’ frailty and has been shown to correlate with mortality in elderly patients even when evaluated by nongeriatricians. The aim of the current study was to determine the prognostic value of CFS in patients who underwent transcatheter aortic valve replacement.

Methods:

We utilized the OCEAN (Optimized Catheter Valvular Intervention) Japanese multicenter registry to review data of 1215 patients who underwent transcatheter aortic valve replacement. Patients were categorized into 5 groups based on the CFS stages: CFS 1-3, CFS 4, CFS 5, CFS 6, and CFS ≥7. We subsequently evaluated the relationship between CFS grading and other indicators of frailty, including body mass index, serum albumin, gait speed, and mean hand grip. We also assessed differences in baseline characteristics, procedural outcomes, and early and midterm mortality among the 5 groups.

Results:

Patient distribution into the 5 CFS groups was as follows: 38.0% (CFS 1-3), 32.9% (CFS4), 15.1% (CFS 5), 10.0% (CFS 6), and 4.0% (CFS ≥7). The CFS grade showed significant correlation with body mass index (Spearman’s ρ=−0.077, P =0.007), albumin (ρ=−0.22, P <0.001), gait speed (ρ=−0.28, P <0.001), and grip strength (ρ=−0.26, P <0.001). Cumulative 1-year mortality increased with increasing CFS stage (7.2%, 8.6%. 15.7%, 16.9%, 44.1%, P <0.001). In a Cox regression multivariate analysis, the CFS (per 1 category increase) was an independent predictive factor of increased late cumulative mortality risk (hazard ratio, 1.28; 95% confidence interval, 1.10–1.49; P <0.001).

Conclusions:

In addition to reflecting the degree of frailty, the CFS was a useful marker for predicting late mortality in an elderly transcatheter aortic valve replacement cohort.

Tissue-engineering-based strategies for regenerative endodontics

Stemming from in vitro and in vivo pre-clinical and human models, tissue-engineering-based strategies continue to demonstrate great potential for the regeneration of the pulp-dentin complex, particularly in necrotic, immature permanent teeth. Nanofibrous scaffolds, which closely resemble the native extracellular matrix, have been successfully synthesized by various techniques, including but not limited to electrospinning. A common goal in scaffold synthesis has been the notion of promoting cell guidance through the careful design and use of a collection of biochemical and physical cues capable of governing and stimulating specific events at the cellular and tissue levels. The latest advances in processing technologies allow for the fabrication of scaffolds where selected bioactive molecules can be delivered locally, thus increasing the possibilities for clinical success. Though electrospun scaffolds have not yet been tested in vivo in either human or animal pulpless models in immature permanent teeth, recent studies have highlighted their regenerative potential both from an in vitro and in vivo (i.e., subcutaneous model) standpoint. Possible applications for these bioactive scaffolds continue to evolve, with significant prospects related to the regeneration of both dentin and pulp tissue and, more recently, to root canal disinfection. Nonetheless, no single implantable scaffold can consistently guide the coordinated growth and development of the multiple tissue types involved in the functional regeneration of the pulp-dentin complex. The purpose of this review is to provide a comprehensive perspective on the latest discoveries related to the use of scaffolds and/or stem cells in regenerative endodontics. The authors focused this review on bioactive nanofibrous scaffolds, injectable scaffolds and stem cells, and pre-clinical findings using stem-cell-based strategies. These topics are discussed in detail in an attempt to provide future direction and to shed light on their potential translation to clinical settings.

Induction of dentine in amputated pulp of dogs by recombinant human bone morphogenetic proteins-2 and -4 with collagen matrix

Recombinant human bone morphogenetic protein (BMP)-2, BMP-4 and transforming growth factor (TGF)-beta 1 combined with collagen matrix as a carrier were examined for their effects on pulp regeneration and dentine formation. Seventy days after implantation of 2 micrograms of BMP-2, mineralized osteodentine-like tissue containing embedded osteodentinocytes was seen in the cavity. Unmineralized fibrous tissue and pulp-like loose connective tissue were also found in the same cavity. In teeth implanted with 660 ng of BMP-2 only unmineralized fibrous and pulp tissues were seen. In teeth with 220 ng of BMP-2 or collagen alone, pulp tissue was seen. It is therefore likely that the cavity fills with pulp tissue and that spindle-shaped cells elaborate extracellular matrix that mineralizes to be osteodentine in a dose-dependent manner. Similar osteodentine was seen in teeth implanted with 4 micrograms of BMP-4 and collagen. No distinct tubular dentine was formed, unlike an earlier experiment in which BMP-2 or -4 was implanted with enriched, inactivated dentine matrix. These findings suggest that both BMP-2 and -4 induce osteodentine formation if combined with collagen matrix; some other matrix component present in inactivated dentine matrix might be essential for further differentiation into odontoblasts. In teeth implanted with TGF-beta 1, the carrier collagen remained in the cavity and little pulp tissue proliferation was seen, suggesting a possible inhibitory effect of TGF-beta 1 in pulp regeneration. It is likely that the response to growth and differentiation factors is dependent on the state of differentiation of pulp cells.

Inhibition of angiotensin I-converting enzyme by Bacillus licheniformis alkaline protease hydrolyzates derived from sardine muscle

Hydrolyzates which inhibit the angiotensin I-converting enzyme (ACE) were prepared from sardine muscle by Bacillus licheniformis alkaline protease. Considering the practical application of preparations as a functional food material, the best proteolytic conditions with respect to taste, solubility and ACE inhibitory activity were a 0.3 wt% addition of the enzyme and 17-h proteolysis at 50 degrees C and pH 9.0. The preparations under these conditions had potent activity (IC50 = 0.26 mg protein/ml). Fractionation of the preparations on an ODS column with ethanol resulted in the production of more potent inhibitors. The most potent activity was obtained when eluting with 10% ethanol (IC50 = 0.015 mg protein/ml). This fraction was apparently rich in acidic amino acids, poor in hydrophobic ones, and effective for use as a physiologically functional food material by virtue of little bitterness, a fish odor and powerful ACE inhibitory activity.

Regulation of pancreatic PC1 and PC2 associated with increased glucagon-like peptide 1 in diabetic rats

The pancreatic processing enzymes, PC1 and PC2, convert proinsulin to insulin and convert proglucagon to glucagon and glucagon-like peptide 1 (GLP-1). We examined the effect of streptozotocin (STZ) treatment on the regulation of these enzymes and the production of insulin, glucagon, and GLP-1 in the rat. Pancreatic PC1 and PC2 mRNA increased >2-fold and >4-fold, respectively, in rats receiving intraperitoneal STZ (50 mg/kg) daily for 5 days. Immunocytochemistry revealed that, although pancreatic islet cells in the STZ-treated rats were sparse and atrophic PC1, PC2, glucagon, and GLP-1 immunoreactivity increased dramatically in the remaining islet cells. Heightened PC1 and PC2 expression was seen in cells expressing glucagon but not in insulin-expressing cells. Furthermore, in STZ-treated rats, bioactive GLP-1(7-36 amide) accumulated in pancreatic extracts and serum 3- and 2.5-fold, respectively, over control animals. This treatment also caused a 2-fold increase in the ratio of amidated forms of GLP-1 immunoreactivity to total glucagon immunoreactivity in the pancreas but did not affect the ratio of proinsulin to insulin. We conclude that hyperglycemic rats have an increased expression of prohormone converting enzymes in islet alpha cells, leading to an increase in amidated GLP-1, which can then exert an insulinotropic effect on the remaining beta cells.

Lung fibroblasts from patients with emphysema show markers of senescence in vitro

BACKGROUND

The loss of alveolar walls is a hallmark of emphysema. As fibroblasts play an important role in the maintenance of alveolar structure, a change in fibroblast phenotype could be involved in the pathogenesis of this disease. In a previous study we found a reduced in vitro proliferation rate and number of population doublings of parenchymal lung fibroblasts from patients with emphysema and we hypothesized that these findings could be related to a premature cellular aging of these cells. In this study, we therefore compared cellular senescence markers and expression of respective genes between lung fibroblasts from patients with emphysema and control patients without COPD.

METHODS

Primary lung fibroblasts were obtained from 13 patients with moderate to severe lung emphysema (E) and 15 controls (C) undergoing surgery for lung tumor resection or volume reduction (n = 2). Fibroblasts (8E/9C) were stained for senescence-associated beta-galactosidase (SA-beta-Gal). In independent cultures, DNA from lung fibroblasts (7E/8C) was assessed for mean telomere length. Two exploratory 12 k cDNA microarrays were used to assess gene expression in pooled fibroblasts (3E/3C). Subsequently, expression of selected genes was evaluated by quantitative PCR (qPCR) in fibroblasts of individual patients (10E/9C) and protein concentration was analyzed in the cell culture supernatant.

RESULTS

The median (quartiles) percentage of fibroblasts positive for SA-beta-Gal was 4.4 (3.2;4.7) % in controls and 16.0 (10.0;24.8) % in emphysema (p = 0.001), while telomere length was not different. Among the candidates for differentially expressed genes in the array (factor > or = 3), 15 were upregulated and 121 downregulated in emphysema. qPCR confirmed the upregulation of insulin-like growth factor-binding protein (IGFBP)-3 and IGFBP-rP1 (p = 0.029, p = 0.0002), while expression of IGFBP-5, -rP2 (CTGF), -rP4 (Cyr61), FOSL1, LOXL2, OAZ1 and CDK4 was not different between groups. In line with the gene expression we found increased cell culture supernatant concentrations of IGFBP-3 (p = 0.006) in emphysema.

CONCLUSION

These data support the hypothesis that premature aging of lung fibroblasts occurs in emphysema, via a telomere-independent mechanism. The upregulation of the senescence-associated IGFBP-3 and -rP1 in emphysema suggests that inhibition of the action of insulin and insulin-like growth factors could be involved in the reduced in vitro-proliferation rate.

Primary Sjögren's syndrome with antibodies to HTLV-I: clinical and laboratory features

The prevalence of antibodies to human T lymphotropic virus type I (HTLV-I) was studied in patients with primary Sjögren's syndrome. Thirteen of 36 serum samples were positive by enzyme linked immunosorbent assay (ELISA) and particle agglutination assay for antibodies to HTLV-I and were confirmed by western blotting. The presence of antibodies to HTLV-I may signify an HTLV-I carrier state. These patients had a high occurrence of extraglandular manifestations such as uveitis, myopathy, and recurrent high fever compared with patients who did not have antibodies to HTLV-I. Patients with antibodies to HTLV-I had an increased spontaneous proliferation of peripheral blood mononuclear cells compared with those without the antibodies. The proportions of activated and memory T cells (HLA-DR+ CD3+, CD25+ CD3+, and CD29+ CD4+ cells) were higher in HTLV-I carriers than in non-carriers. The presence of antibodies to HTLV-I in some patients with primary Sjögren's syndrome suggests that HTLV-I may cause primary Sjögren's syndrome or its extraglandular manifestations, or both.

Single- and multiple-dose pharmacokinetics of AM-1155, a new 6-fluoro-8-methoxy quinolone, in humans

The pharmacokinetics of AM-1155, a new 6-fluoro-8-methoxy quinolone, was examined in healthy male volunteers after the oral administration of a single dose of 100, 200, 400, or 600 mg and multiple doses of 300 mg twice daily for 6.5 days (13 total doses). Throughout the whole study period, AM-1155 was well tolerated in every subject. In the single-dose study, the concentrations in serum reached a peak between 1 and 2 h, and the peak concentrations were 0.873, 1.71, 3.35, and 5.41 micrograms/ml at the doses of 100, 200, 400, and 600 mg, respectively. The elimination half-life was 7 to 8 h, independently of the doses. The unchanged drug was excreted mainly in the urine, with 82 to 88% of the doses appearing for 72 h. The fecal recovery of the unchanged drug amounted to 5.7% for 72 h after a single oral administration of a 400-mg dose. Urinary excretion of metabolites was minimal. The serum protein binding was 20%, independently of the concentrations in serum. The concentrations in saliva were approximately 80% of those in serum. The intake of food had no effect on the pharmacokinetic parameters and urinary excretion of AM-1155 except the slight decrease in area under the concentration-time curve. The concurrent administration of probenecid prolonged the elimination half-life, increased the area under the concentration-time curve, and decreased the apparent total body clearance, renal clearance, urinary recovery of unchanged drug, and the excretion ratio (intrinsic renal clearance of AM-1155/creatinine clearance). This indicated that the tubular secretion contributed to the renal excretion of AM-1155. In the multiple-dose study, the concentrations of AM-1155 in serum and urine reached a steady state within 2 to 3 days. The measured concentrations in serum fitted well the simulation curve, which reflected the persistence of linear pharmacokinetics of AM-1155. In conclusion, AM-1155 is expected to be clinically useful because of its potent antibacterial activity and favorable pharmacokinetics.

Pilot study of the uricosuric effect of DuP-753, a new angiotensin II receptor antagonist, in healthy subjects

The uricosuric effect of DuP-753, a novel, specific angiotensin II receptor antagonist, has been explored in a healthy male Japanese volunteers, given single oral doses of 25, 50, 100 or 200 mg (n = 6), or 100 mg (n = 6) or placebo (n = 3) once daily for 7 consecutive days. In the single-dose study, serum uric acid measured at 4 h after dosing showed a dose dependent decrease; the reductions from the corresponding pre-dose values were: 0.32 (25 mg), 0.77 (50 mg), 1.25 (100 mg) and 1.33 mg.dl-1 (200 mg). The urinary excretion of uric acid within the first 4 h after treatment was also increased in a dose-dependent manner, whereas the urinary excretion of creatinine remained unchanged. In the multiple-dose study, DuP-753 significantly decreased the serum uric acid concentration measured 4 h both after the first (pre-dose value: 5.68 vs 4 h after: 4.48 mg.dl-1) and last administrations (4.42 mg.dl-1). Simultaneously, the ratio of urinary uric acid to creatinine excretion was significantly increased within the first 4 h both after the first (DuP-753: 1.190 vs placebo: 0.576) and last administrations (1.02 vs 0.576). The findings suggest that DuP-753 possesses a uricosuric effect both after single and multiple doses in healthy subjects. The effect should be further examined in hypertensive patients.

Targeting Excessive EZH1 and EZH2 Activities for Abnormal Histone Methylation and Transcription Network in Malignant Lymphomas

Although global H3K27me3 reprogramming is a hallmark of cancer, no effective therapeutic strategy for H3K27me3-high malignancies harboring EZH2^WT/WT has yet been established. We explore epigenome and transcriptome in EZH2^WT/WT and EZH2^WT/Mu aggressive lymphomas and show that mutual interference and compensatory function of co-expressed EZH1 and EZH2 rearrange their own genome-wide distribution, thereby establishing restricted chromatin and gene expression signatures. Direct comparison of leading compounds introduces potency and a mechanism of action of the EZH1/2 dual inhibitor (valemetostat). The synthetic lethality is observed in all lymphoma models and primary adult T cell leukemia-lymphoma (ATL) cells. Opposing actions of EZH1/2-polycomb and SWI/SNF complexes are required for facultative heterochromatin formation. Inactivation of chromatin-associated genes (ARID1A, SMARCA4/BRG1, SMARCB1/SNF5, KDM6A/UTX, BAP1, KMT2D/MLL2) and oncovirus infection (HTLV-1, EBV) trigger EZH1/2 perturbation and H3K27me3 deposition. Our study provides the mechanism-based rationale for chemical dual targeting of EZH1/2 in cancer epigenome.