Regulation of calprotectin expression by interleukin-1? and transforming growth factor-? in human gingival keratinocytes

BACKGROUND AND OBJECTIVE

Calprotectin, a heterodimer of S100A8 and S100A9 with antimicrobial properties, is expressed in gingival keratinocytes and plays an important role in innate immunity. Because calprotectin expression is localized in the spinous cell layer of the gingival epithelium, we hypothesized that the expression of calprotectin in keratinocytes is related to the differentiation stage. The aim of the present study was to investigate the relationship between calprotectin expression and keratinocyte differentiation using some factors that regulated its differentiation.

MATERIAL AND METHODS

Normal human gingival keratinocytes were isolated from gingival tissues obtained at the extraction of wisdom teeth, and were cultured in serum-free keratinocyte medium supplemented with interleukin-1alpha or calcium, which promote keratinocyte differentiation, and transforming frowth factor-beta (TGF-beta) or retinoic acid, which suppress its differentiation. The expression of S100A8/A9 mRNA and the production of calprotectin in normal human gingival keratinocytes were examined by northern blotting and enzyme-linked immunosorbent assay, respectively. The expression of cytokeratin 14, involucrin and filaggrin (marker proteins of keratinocyte differentiation) was investigated by immunohistochemical staining, and the DNA-binding activity of CCAAT/enhancer binding protein alpha (C/EBPalpha), a transcription factor, was examined by electrophoretic mobility shift assay.

RESULTS

The expression of S100A8/A9 mRNA and the production of calprotectin were increased by interleukin-1alpha and calcium, but decreased by TGF-beta. RA inhibited the expression of S100A8/A9 and keratinocyte differentiation, which were induced by interleukin-1alpha. C/EBPalpha DNA-binding activity in normal human gingival keratinocytes was enhanced by interleukin-1alpha and calcium, but suppressed by TGF-beta.

CONCLUSION

The present study suggests that calprotectin expression is related to keratinocyte differentiation and that C/EBPalpha is a regulator of calprotectin expression in keratinocytes.

Shear stress facilitates tissue-engineered odontogenesis

Numerous studies have demonstrated the effect of shear stress on osteoblasts, but its effect on odontogenic cells has never been reported. In this study, we focused on the effect of shear stress on facilitating tissue-engineered odontogenesis by dissociated single cells. Cells were harvested from the porcine third molar tooth at the early stage of crown formation, and the isolated heterogeneous cells were seeded on a biodegradable polyglycolic acid fiber mesh. Then, cell-polymer constructs with and without exposure to shear stress were evaluated by in vitro and in vivo studies. In in vitro studies, the expression of both epithelial and mesenchymal odontogenic-related mRNAs was significantly enhanced by shear stress for 2 h. At 12 h after exposure to shear stress, the expression of amelogenin, bone sialoprotein and vimentin protein was significantly enhanced compared with that of control. Moreover, after 7 days, alkaline phosphatase activity exhibited a significant increase without any significant effect on cell proliferation in vitro. In vivo, enamel and dentin tissues formed after 15 weeks of in vivo implantation in constructs exposure to in vitro shear stress for 12 h. Such was not the case in controls. We concluded that shear stress facilitates odontogenic cell differentiation in vitro as well as the process of tooth tissue engineering in vivo.

Prostate cancer incidence varies among males from different Y-chromosome lineages

The incidence rate of prostate cancer in African-American males is two times higher than Caucasian men and ten times higher than Japanese men. The geographical specificity of Y haplogroups implies that males from different ethnic groups undoubtedly have various Y lineages with different Y-chromosomal characteristics that may affect their susceptibility or resistance to such a male-specific cancer. To confirm this hypothesis we studied the Y-chromosomal haplogroups of 92 Japanese prostate cancer patients comparing them with randomly selected 109 unrelated healthy Japanese male controls who were confirmed to be residents of the same geographical area. Males could be classified using three binary Y-chromosome markers (sex-determining region Y (SRY), YAP, 47z) into four haplogroups DE, O2b(*), O2b1, and untagged group. Our results confirmed that prostate cancer incidence varies among males from different Y-chromosome lineages. Males from DE and the untagged haplogroups are at a significantly higher risk to develop prostate cancer than O2b(*) and O2b1 haplogroups (P=0.01), odds ratio 2.17 and 95% confidence interval (1.16-4.07). Males from haplogroup DE are over-represented in the patient group showing a percentage of 41.3%. The underlying possible causes of susceptibility variations of different Y lineages for such a male-specific cancer tumorigenesis are discussed. These findings explain the lower incidence of prostate cancer in Japanese and other South East Asian males than other populations. To our knowledge, this is the first reliable study examining the association between prostate cancer and Y-chromosomal haplogroups, comparing prostate cancer patients with carefully selected matched controls.

Alpha 2 integrin +807 polymorphism in drug-induced gingival overgrowth

Alpha2 integrin on fibroblasts is reported to play an important role in the induction of drug-induced gingival overgrowth, which is characterized by excessive accumulation of type I collagen in gingival connective tissue. Silent polymorphism 807 T/C within the alpha2 integrin gene is associated with high/low alpha2 integrin expression. The aim of this study was to test the hypothesis that expression of alpha2 integrin 807 T/C polymorphism correlates with drug-induced gingival overgrowth. A case-control study comparing 136 subjects taking calcium channel blockers (72 with vs. 64 without drug-induced gingival overgrowth) demonstrated that the frequency of the +807 C allele was significantly higher in the case group than in the controls (odds ratio, 3.61; 95% confidence interval, 2.14 - 6.10; P < 0.05). The present findings suggest that the alpha2 +807 C allele is one of the genetic risk factors for drug-induced gingival overgrowth.

A novel culture system for porcine odontogenic epithelial cells using a feeder layer

The growth of cells in vitro can provide useful models for investigating their behaviour and improving our understanding of their function in vivo. Although the developmental regulation of enamel matrix formation has been comprehensively analysed, the detailed cellular characteristics of ameloblasts remain unclear because of the lack of a system of long-term in vitro culture. Therefore, the establishment of odontogenic epithelial cell lines has taken on a new significance. Here, we report on a novel porcine odontogenic epithelial cell-culture system, which has permitted serial culture of these cells. Epithelial cells were harvested from third molar tooth buds in the fresh mandibles of 6-month-old pigs, and seeded on dishes in D-MEM containing 10% FBS. Before the cells reached confluence, the medium was changed to LHC-9 to select the epithelial cells. When trypsinized epithelial cells were plated together with 3T3-J2 cells as a feeder layer, the epithelial cells grew from single cells into colonies. The colonies then expanded and became confluent, and could be sub-cultured for up to 20 passages. The long-term culture cells expressed mRNA for amelogenin and ameloblastin, as well as enamelysin (MMP-20), which is a tissue-specific gene product unique to ameloblasts. These results show that the system is capable of sustaining the multiplication of odontogenic epithelial cells with the characteristics of ameloblasts.

Replica multichannel polymer chips with a network of sacrificial channels sealed by adhesive printing method

Replica microchips for capillary array electrophoresis containing 10 separation channels (50 microm width, 50 microm depth and 100 microm pitch) and a network of sacrificial channels (100 microm width and 50 microm depth) were successfully fabricated on a poly(methyl methacrylate) (PMMA) substrate by injection molding. The strategy involved development of moving mask deep X-ray lithography to fabricate an array of channels with inclined channel sidewalls. A slight inclination of channel sidewalls, which can not be fabricated by conventional deep X-ray lithography, is highly required to ensure the release of replicated polymer chips from a mold. Moreover, the sealing of molded PMMA multichannel chips with a PMMA cover film was achieved by a novel bonding technique involving adhesive printing and a network of sacrificial channels. An adhesive printing process enables us to precisely control the thickness of an adhesive layer, and a network of sacrificial channels makes it possible to remove air bubbles and an excess adhesive, which are crucial to achieving perfect sealing of replica PMMA chips with well-defined channel and injection structures. A CCD camera equipped with an image intensifier was used to simultaneously monitor electrophoretic separations in ten micro-channels with laser-induced fluorescence detection. High-speed and high-throughput separations of a 100 bp DNA ladder and phi X174 Hae III DNA restriction fragments have been demonstrated using a 10-channel PMMA chip. The current work establishes the feasibility of mass production of PMMA multichannel chips at a cost-effective basis.

Energy metabolism and cerebral blood flow during cytotoxic brain edema induced by 6-aminonicotinamide

We investigated the progression of cytotoxic brain edema induced by 6-aminonicotinamide (6-ANA), a potent antimetabolite of nicotinamide, by measuring the time courses of changes in brain tissue water state (with MRI), histology (with H&E staining), energy metabolism (with 31P-NMR), brain hemoglobin concentration (with near-infrared spectroscopy; NIRS), cerebral blood flow and volume (CBF. CBV), mean arterial blood pressure (MABP), and brain activity (with EEG) up to 10 hours (h). Change in cerebrovascular autoregulation was also investigated. 6-ANA (120 mg/kg) was administered intraperitoneally to 30 male Wistar rats (250-350 g). After 10 h, the T2-weighted signal intensity was increased (p < 0.05), and H&E staining showed severe vacuolation of glial cells. ATP production/consumption and intracellular pH were well maintained up to 10 h, while the intensity of the phosphomonoesters (PME) signal was significantly increased (p < 0.05). Oxygen consumption gradually decreased from 4 to 10 h. CBF and MABP were all significantly increased (by 2.5-fold for CBF) (p < 0.05). Theta and delta wave amplitudes were reduced at 10 h. In summary, 6-ANA (120 mg/kg) induced cytotoxic brain edema from 4 to 10 h. Energy balance and brain activity were well maintained up to 10 h, though cerebrovascular autoregulation was impaired.

Distribution of ammonia-oxidizing bacteria in sewage activated sludge: analysis based on 16S rDNA sequence

This study carried out analysis of ammonia-oxidizing bacteria (AOB) communities in 12 sewage activated sludge systems standing in eight sewage treatment plants located in Tokyo. The systems were different in the treatment process configuration: anaerobic/anoxic/aerobic (A20), anaerobic/aerobic (AO), and conventional activated sludge (AS) processes. AOB communities were analyzed by sequences of 16S rDNA amplicons, which were separated by denaturing gradient gel eletrophoresis (DGGE) after specific polymerase chain reaction (PCR) amplification. The results demonstrated that low ammonium concentrations in the influents of the 12 sewage activated sludge systems resulted in the dominance of Nitrosomonas oligotropha-like sequences. Further, Nitrosomonas europaea- and Nitrosomonas cryotolerans-like sequences were recovered from only one A20 system of which the influent contained higher ammonium and chloride concentrations than those of other systems. Nitrosomonas communis-like sequences were found in every A20 and AO system, but mostly not found in every AS system. In summary, influent characteristics and treatment process configuration affected the AOB communities in the 12 sewage activated sludge systems.

Three TNFalpha single nucleotide polymorphisms in the Japanese population

BACKGROUND

Tumour necrosis factor-alpha (TNFalpha) is an essential regulator of immune responses and is implicated to relate to several types of disease susceptibilities. Population information on polymorphisms is essential for the study of genetic diseases.

AIM

To obtain accurate information about single nucleotide polymorphisms (SNPs) in the TNFalpha gene in the Japanese population.

SUBJECTS AND METHODS

The entire TNFalpha gene was screened for SNPs by directly sequencing 48 chromosomes derived from 24 unrelated Japanese individuals. Allele frequencies of each polymorphism were determined and compared with those previously reported in other populations.

RESULTS

Three SNPs, -308G/A at nt -308, IVS1 + 125G/A at nt 492 and IVS3 + 104G/A at nt 1359 were observed, of which one (IVS3 + 104G/A at nt 1359) was novel. In addition, allele frequencies of -308G/A were remarkably different from those presented in the NCBI dbSNP, indicating a significant ethnic difference.

CONCLUSIONS

The polymorphisms and allele frequencies obtained in this study will be useful for genetic studies of common diseases such as osteoporosis and rheumatoid arthritis in the Japanese population.

Gait disorders and leg deformities in children

Gait disorders and leg deformities have become the most prevalent orthopedic problems in children in Japan. Usually, at the first visit to our outpatient clinics, there are many difficulties in fully determining the causes and prognoses of these problems. Several series of observations, carried out at intervals, will be required to ascertain whether these problems are really pathologic or whether they are actually within the normal range. In-toeing gait and bow-legged deformities were the most common complaints observed in each of the above problems. The conditions in the majority of such patients were observed to spontaneously improve with time. However, we must always focus on the patient's past history, beginning from infancy, and we must carry out some physical examinations so as not to overlook any actual disorders underlying the patient's present condition.

Distribution of brain oedema in the contralateral hemisphere after cerebral infarction: repeated MRI measurement in the rat

The appearance of local cerebral dysfunction at remote regions from the focus in the acute stage of stroke (diaschisis) is well known, but its mechanism has not been established. We have analysed serial MR images of the infarcted brain of rats to evaluate the distribution of oedema. Forty-seven Sprague-Dawley rats were anaesthetized with halothane, and the right middle cerebral artery (MCA) was permanently occluded via the intraluminal approach using a nylon 2-0 suture. At 3, 6, 9 and 24 hours after the occlusion, coronal T(2)-weighted MR images were taken and the signal intensity (SI) was computed at each region of the brain. After occlusion of the right MCA, SI increased diachronically up to 24 hours on the occluded side of the cortex (52.9+/-3.2 to 104.8+/-22.4) and striatum, which are within the perfusion territory of the MCA. SI increment was also observed at the hippocampus, alveus hippocampi and pyriform lobe, which are not within the territory of the MCA, and at some regions of the contralateral side (52.5+/-4.8 to 69.4+/-14.8 at the cortex). These changes were prominent in ischaemia-vulnerable portions, mild in the cortex, and minimal in the striatum. This contralateral side SI increment indicates remote oedema, which corresponds to diaschisis. We suggest that the mechanism of this remote contralateral oedema is the movement of extravasated protein from the lesion.

Natural history of infantile tibia vara

We have observed the natural history without treatment of 46 limbs in 29 patients with infantile tibia vara and a metaphyseal-diaphyseal angle (MDA) of more than 11 degrees. The femorotibial angle (FTA) and MDA were measured, and Langenskiöld's classification of radiological changes in the proximal medial metaphysis of the tibia was used. In 22 limbs which were not in Langenskiöld stages II to III the condition resolved spontaneously without treatment. Of the remaining 24 which were in stages II to III, in 18 it resolved spontaneously by the age of six years, but six showed little or no improvement at the latest follow-up. It was impossible to differentiate by measuring the FTA or MDA whether spontaneous resolution could be expected before the age of four years. There was no difference in the rate of resolution of the deformity between those patients who had been treated by a brace and those who had received no treatment. We advise no initial treatment but review at six-monthly intervals until the age of four years, even in patients with Langenskiöld stage-II to stage-III deformity. When a deformity persisted or progressed we carried out a corrective osteotomy after the age of four years.

Thirteen single-nucleotide polymorphisms in the human osteopontin gene identified by sequencing of the entire gene in Japanese individuals

Osteopontin (OPN) is one of the major noncollagenous bone matrix proteins produced by osteoblasts and osteoclasts. We systematically surveyed the entire structure of the OPN gene for single-nucleotide polymorphisms (SNPs) by directly sequencing 48 alleles derived from 24 unrelated Japanese individuals. We identified 13 SNPs in the OPN gene. Ten polymorphisms were identified in introns 1, 3, and 5; 2 in the coding region of exons 6 and 7; and 1 in the 3' untranslated region of exon 7. Allele frequencies for some of the polymorphisms were significantly different from those reported in the United States National Center for Biotechnology Information (NCBI) dbSNP database. These polymorphisms will be useful in genetic studies to evaluate the role of OPN proteins in bone metabolism.

Linkage disequilibrium and haplotype analysis among ten single-nucleotide polymorphisms of interleukin 11 identified by sequencing of the gene

Interleukin (IL11) is a member of the interleukin 6 (IL6)-related cytokine subfamily, which stimulates T cell-dependent development of immunoglobulin-producing B cells. IL11 is also an important paracrine regulator of bone metabolism that induces formation of osteoclasts. In the work reported here, we sequenced the entire IL11 structural gene of 48 alleles in a Japanese test population. These experiments identified ten single-nucleotide polymorphisms (SNPs) and determined their allelic frequencies. One polymorphism was identified upstream of exon 1, one in exon 3, four in intron 4 and four in the 3' untranslated region (3'UTR) of exon 5. Based on the genotype data, we constructed six haplotypes in the tested population. Two-way comparisons of SNPs revealed two combinations in complete linkage disequilibrium, one with SNPs at nucleotide positions 2753, 3644, 5154, and 5568, and another with SNPs at positions 3686, 5141, and 5734. These results will be useful in disease-association studies where a contribution of the human IL11 gene has been suspected, especially in disorders affecting immune response and bone metabolism.

Pharmacokinetic studies of methionine in rats using deuterium-labeled methionine quantitative assessment of remethylation

The pharmacokinetics of methionine has been studied in rats by means of stable isotope methodology. After the i.v. bolus injection of [2H7]methionine (5 mg/kg body wt.), the plasma concentrations of [2H7]methionine, demethylated [2H4]homocysteine and remethylated [2H4]methionine were determined simultaneously with endogenous methionine and homocysteine by gas chromatography-mass spectrometry. The half-life for [2H7]methionine were 35.0 +/- 6.9 min. The appearance of the metabolites, [2H4]homocysteine and [2H4]methionine, in the plasma was very rapid. The fraction of [2H7]methionine that remethylated to [2H4]methionine through [2H4]homocysteine were 0.185 +/- 0.028. The administered [2H7]methionine did not influence the plasma levels of endogenous methionine and homocysteine. The present stable isotope methodology has made it possible to evaluate the pharmacokinetics of methionine, including the estimation of remethylation.

Unprecedented sugar-dependent in vivo antitumor activity of carbohydrate-pendant cis-diamminedichloroplatinum(II) complexes

Eight carbohydrate-pendant platinum(II) complexes have been synthesized from carbohydrate-diamine conjugates. D-Glucose, D-mannose, D-galactose, D-xylose, and L-glucose are attached to the dichloroplatinum(II) moiety by 1,3- or 1,2-diaminopropane chelates through with an O-glycoside bond. All the carbohydrate moieties reduced the toxicity inherent with platinum(II) complexes.

Quantitative studies on the nuclear transport of plasmid DNA and gene expression employing nonviral vectors

The nuclear membrane is the main barrier to nonviral gene delivery. Thus, in the case of nondividing cells, a device for nuclear delivery of exogenous DNA is necessary. In addition, to precisely evaluate the efficacy of various plasmid modifications and/or nonviral vectors, it is necessary to measure, not only gene expression but also the amount of delivered plasmid DNA into the subcellular compartment, particularly the nucleus. Moreover, it is also necessary to examine effects of the state of the plasmid DNA in the nucleus or various modifications of the plasmid DNA on the process after nuclear transport, i.e., transcription. Here, we address the issues of (1) the efficient delivery of genetic materials using a nuclear localization signal (NLS), (2) the quantitative evaluation of plasmid DNA delivered to the nucleus and the relationship between the amount of plasmid DNA delivered into the nucleus and gene expression, and (3) methods for evaluating of the effect of the state of plasmid DNA on transcription in vitro.

Effects of food intake and age on the pharmacokinetics of AS-924, a novel ester-type cephem antibiotic. Comparison with cefpodoxime proxetil

The effects of food intake and age on intestinal absorption of AS-924, a novel prodrug-type cephem antibiotic, were examined in 16 healthy adult volunteers (eight young volunteers and eight elderly volunteers) by the cross-over method, using cefpodoxime proxetil (CPOD-PR) as the control drug. The gastrointestinal absorption of AS-924 and CPOD-PR was increased slightly by food intake and the extent of increase was slightly greater after administration of CPOD-PR. The absorption of AS-924 was not affected by age, whereas intestinal absorption of CPOD-PR increased with age. In conclusion, these results confirmed that AS-924 has the unique characteristics as a novel prodrug and that its absorption is less likely to be affected by food intake and age.