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1.
Sci Rep ; 14(1): 926, 2024 01 09.
Article in English | MEDLINE | ID: mdl-38195985

ABSTRACT

Although novel techniques for avoiding incontinence during robot-assisted radical prostatectomy have been developed, long-term oncological outcomes are unknown. The objective of this study was to determine the long-term oncological outcomes and functional outcomes of novel nerve-sparing robot-assisted radical prostatectomy with endopelvic fascia preservation for a single surgeon. Data from 100 patients who underwent structure-preserving prostatectomies performed by a single surgeon were retrospectively analyzed. The median console time was 123 min. Bilateral nerve-sparing was performed in 43% of patients underwent, and 57% underwent unilateral nerve-sparing surgery. Most patients (96%) reached complete pad-zero urinary continence by one year after surgery. Satisfactory erectile function was achieved in 97% of patients who underwent bilateral nerve-sparing surgery, and 80% of patients who underwent unilateral nerve-sparing surgery. The surgical margin was positive for 25% of patients, and the biochemical recurrence-free rate at 5 years was 77%. The cancer-specific survival rate was 100% during the median follow-up period of 4.5 years. Clavien-Dindo grade III complications occurred in 1% of cases. The outcomes for novel nerve-sparing robot-assisted radical prostatectomy with endopelvic fascia preservation were similar to previously reported oncological outcomes, with satisfactory functional outcomes. This operative method may be useful for patients who are eligible for nerve-sparing surgery.


Subject(s)
Robotics , Surgeons , Male , Humans , Retrospective Studies , Prostatectomy , Fascia
2.
J Mol Biol ; 432(19): 5378-5389, 2020 09 04.
Article in English | MEDLINE | ID: mdl-32795534

ABSTRACT

Rhodopsin is the photosensitive protein, which binds to 11-cis-retinal as its chromophore. In the dark, rhodopsin exists as a stable complex between the opsin moiety and 11-cis-retinal. The absorption of a light photon converts 11-cis-retinal to all-trans-retinal and initiates our vision. As a result, the increase in the rate of dark activation of rhodopsin reduces its photosensitivity resulting in night blindness. The mutations, G90D and T94I are night blindness-causing mutations that exhibit completely different physicochemical characteristics associated with the dark activation of rhodopsin, such as a high rate of thermal isomerization of 11-cis-retinal and a slow pigment regeneration. To elucidate the molecular mechanism by which G90D and T94I mutations affect rhodopsin dark activation and regeneration, we performed light-induced difference FTIR spectroscopy on dark and primary photo-intermediate states of G90D and T94I mutants. The FTIR spectra clearly show that both charged G90D and hydrophobic T94I mutants alter the H-bond network at the Schiff base region of the chromophore, which weakens the electrostatic interaction with Glu113 counterion. Our results further show an altered water-mediated H-bond network around the central transmembrane region of mutant rhodopsin, which is reminiscent of the active Meta-II state. This altered water-mediated H-bond network may cause thermal isomerization of the chromophore and facilitate rhodopsin dark activation.


Subject(s)
Night Blindness/genetics , Rhodopsin/genetics , Animals , Cattle , Hydrogen Bonding , Isomerism , Models, Molecular , Night Blindness/metabolism , Point Mutation , Protein Conformation , Retinaldehyde/chemistry , Retinaldehyde/genetics , Retinaldehyde/metabolism , Rhodopsin/chemistry , Rhodopsin/metabolism
3.
Breed Sci ; 66(3): 425-33, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27436953

ABSTRACT

Rice bran oil is a byproduct of the milling of rice (Oryza sativa L.). It offers various health benefits and has a beneficial fatty acid composition. To increase the amount of rice bran as a sink for triacylglycerol (TAG), we developed and characterized new breeding materials with giant embryos. To induce mutants, we treated fertilized egg cells of the high-yielding cultivar 'Mizuhochikara' with N-methyl-N-nitrosourea (MNU). By screening M2 seeds, we isolated four giant embryo mutant lines. Genetic analysis revealed that the causative loci in lines MGE12 and MGE13 were allelic to giant embryo (ge) on chromosome 7, and had base changes in the causal gene Os07g0603700. On the other hand, the causative loci in lines MGE8 and MGE14 were not allelic to ge, and both were newly mapped on chromosome 3. The TAG contents of all four mutant lines increased relative to their wild type, 'Mizuhochikara'. MGE13 was agronomically similar to 'Mizuhochikara' and would be useful for breeding for improved oil content.

4.
Am J Orthod Dentofacial Orthop ; 146(3): 355-63, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25172258

ABSTRACT

INTRODUCTION: Mandibular growth is believed to be strongly related to mastication. Furthermore, mandibular condylar cartilage is known to be derived from neural crest cells. We examined whether the degree of chewing affects condylar cartilage growth of the mandible. METHODS: Mice were fed diets with varying hardness. Genes specific to neural crest-derived cells were measured by real-time polymerase chain reaction to compare the expression changes between the mandibular and tibia cartilages. The mandibular condylar cartilage was then evaluated histologically, and proliferation was evaluated using proliferating cell nuclear antigen. Immunostaining was conducted for osteopontin, type X collagen, and Musashi1, and real-time polymerase chain reaction was used to assess the expression levels of osteopontin and type X collagen. RESULTS: Markers including P75, Wnt-1, Musashi1, and Nestin were upregulated in the mandibular condylar cartilage as compared with the tibial cartilage. Histologic assessment of the mandibular cartilage showed that the hypertrophic chondrocyte zone was statistically significantly thicker in mice fed a hard diet. Chondrocyte proliferation and Musashi1 expression were lower in mice fed a hard diet. After 4 weeks, numerous osteopontin and type X collagen-positive cells were observed in mice fed a mixed diet. CONCLUSIONS: Mastication affects the balance between differentiation and proliferation in the mandibular condylar cartilage. This phenomenon might be attributed to the presence of neural crest-derived cells.


Subject(s)
Cartilage, Articular/growth & development , Mandibular Condyle/growth & development , Mastication/genetics , Animal Feed/classification , Animals , Cartilage, Articular/anatomy & histology , Cell Differentiation/genetics , Cell Proliferation , Chondrocytes/cytology , Collagen Type X/analysis , Gene Expression/genetics , Hardness , Male , Mandibular Condyle/anatomy & histology , Menisci, Tibial/anatomy & histology , Menisci, Tibial/growth & development , Mice , Nerve Tissue Proteins/analysis , Nestin/analysis , Neural Crest/cytology , Neural Crest/metabolism , Osteopontin/analysis , Proliferating Cell Nuclear Antigen/analysis , RNA-Binding Proteins/analysis , Random Allocation , Real-Time Polymerase Chain Reaction , Receptors, Nerve Growth Factor/analysis , Time Factors , Up-Regulation , Wnt1 Protein/analysis
5.
Exp Dermatol ; 23(10): 764-6, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25056219

ABSTRACT

Different biomarkers are used to evaluate the severity of atopic dermatitis (AD); however, it remains difficult to determine the severity of localized skin lesions. MIF plays an essential role in the pathophysiology of skin inflammation. To establish whether the MIF level in the stratum corneum (SC) serves as a marker of the severity of AD lesions, we examined the SC MIF (scMIF) levels in AD patients. The SC of the cheek, neck and upper arm skin was collected using tape stripping, and the scMIF levels were measured. Consequently, the scMIF levels were found to be significantly higher in the involved skin lesions than the uninvolved areas within the same patient. Moreover, the scMIF levels were significantly correlated with the severity of local skin lesions. These findings suggest that the scMIF level can be used as an effective marker for evaluating the local severity of AD.


Subject(s)
Dermatitis, Atopic/metabolism , Intramolecular Oxidoreductases/metabolism , Macrophage Migration-Inhibitory Factors/metabolism , Adolescent , Adult , Biomarkers/blood , Biomarkers/metabolism , Case-Control Studies , Dermatitis, Atopic/blood , Dermatitis, Atopic/pathology , Epidermis/metabolism , Epidermis/pathology , Female , Humans , Intramolecular Oxidoreductases/blood , Macrophage Migration-Inhibitory Factors/blood , Male , Middle Aged , Young Adult
6.
Am J Pathol ; 178(2): 679-87, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21281800

ABSTRACT

UV radiation indirectly regulates melanogenesis in melanocytes through a paracrine regulatory mechanism involving keratinocytes. Protease-activated receptor (PAR)-2 activation induces melanosome transfer by increasing phagocytosis of melanosomes by keratinocytes. This study demonstrated that macrophage migration inhibitory factor (MIF) stimulated PAR-2 expression in human keratinocytes. In addition, we showed that MIF stimulated stem cell factor (SCF) release in keratinocytes; however, MIF had no effect on the release of endothelin-1 or prostaglandin E2 in keratinocytes. In addition, MIF had no direct effect on melanin and tyrosinase synthesis in cultured human melanocytes. The effect of MIF on melanogenesis was also examined using a three-dimensional reconstituted human epidermal culture model, which is a novel, commercially available, cultured human epidermis containing functional melanocytes. Migration inhibitory factor induced an increase in melanin content in the epidermis after a 9-day culture period. Moreover, melanin synthesis induced by UV-B stimulation was significantly down-regulated by anti-MIF antibody treatment. An in vivo study showed that the back skin of MIF transgenic mice had a higher melanin content than that of wild-type mice after 12 weeks of UV-B exposure. Therefore, MIF-mediated melanogenesis occurs mainly through the activation of PAR-2 and SCF expression in keratinocytes after exposure to UV-B radiation.


Subject(s)
Keratinocytes/metabolism , Macrophage Migration-Inhibitory Factors/pharmacology , Melanins/biosynthesis , Receptor, PAR-2/metabolism , Stem Cell Factor/metabolism , Ultraviolet Rays , Animals , Cell Survival/drug effects , Cell Survival/radiation effects , Cells, Cultured , Epidermis/drug effects , Epidermis/metabolism , Epidermis/radiation effects , Humans , Keratinocytes/drug effects , Keratinocytes/pathology , Keratinocytes/radiation effects , Melanocytes/drug effects , Melanocytes/enzymology , Melanocytes/pathology , Melanocytes/radiation effects , Mice , Mice, Transgenic , Models, Biological , Monophenol Monooxygenase/metabolism , Skin Pigmentation/drug effects , Skin Pigmentation/radiation effects , Time Factors , Tissue Culture Techniques
7.
J Periodontol ; 81(9): 1264-72, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20476887

ABSTRACT

BACKGROUND: In the clinical field of jawbone formation, the use of autogenous bone as the graft material is the gold standard. However, there are some problems with this technique, such as risk of infection on the donor side, the limited amount of available bone mass, and marked resorption of the grafted bone. We investigated the potential for using teeth as a bone graft material for jawbone formation because the dental pulp contains stem cells, including undifferentiated neural crest-derived cells. METHODS: Alveolar bone defects were created in Wistar rats, and the defects were filled with either tooth or iliac bone graft material, or left as controls. The potential for using teeth as a bone graft material for jawbone formation was measured using real-time polymerase chain reaction, microcomputed tomography, and histologic analysis. RESULTS: Polymerase chain reaction revealed that the expressions of P75, P0, nestin, and musashi-1 were significantly higher in teeth than in mandibular bone and iliac bone grafts. Hematoxylin and eosin staining and microcomputed tomography showed that at 8 weeks, tooth graft material produced a similar amount of new bone compared to iliac bone graft material. Osteopontin was expressed in both the tooth and iliac bone graft material at 6 and 8 weeks after surgery. Dentin sialoprotein was expressed in the tooth graft material in the new bone at 6 weeks only. CONCLUSION: These results indicate that teeth may be an alternative material to autogenous bone for treating alveolar bone defects by grafting.


Subject(s)
Alveolar Bone Loss/surgery , Guided Tissue Regeneration, Periodontal/methods , Tooth/transplantation , Animals , Bone Regeneration , Bone Substitutes , Bone Transplantation , Bone and Bones/metabolism , Extracellular Matrix Proteins/biosynthesis , Male , Mandible/surgery , Nerve Tissue Proteins/biosynthesis , Osteopontin/biosynthesis , Phosphoproteins/biosynthesis , Rats , Rats, Wistar , Sialoglycoproteins/biosynthesis , Tooth/metabolism
8.
Eur J Orthod ; 32(1): 66-70, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19648440

ABSTRACT

It is well known that mastication has a significant influence on mandibular growth and development, but the mechanism behind this effect has not yet been clarified. Furthermore, no studies have examined the effects of changes in mastication on the three-dimensional (3D) morphometry of the mandible. The aim of the present study was to investigate the influences of changes in mastication on mandibular growth and morphology. Twenty-five 3-week-old (at the time of weaning) imprinting control region mice were randomly divided into three groups: mice fed a hard diet (HD), mice fed a soft diet (SD), and mice alternately fed hard and soft diets (HSDs) every week for 4 weeks. The morphometry of the mandible was analysed using 3D microcomputed tomography (muCT). Statistical analysis was undertaken using a t-test. muCT analysis showed that the condylar width was significantly greater in the HD group than in the SD group after 1 week. After 4 weeks, mandibular length was significantly longer and ramus height was greater in the HSD group than in the other two groups. Bone volume was significantly less in the SD group than in the other two groups after 4 weeks. These findings suggest that changes in mastication markedly affect mandibular condylar cartilage growth and mandibular morphology. It is considered that dietary education at an early age is important in order to prevent disruption of the development of the mandible.


Subject(s)
Adaptation, Physiological , Mandible/growth & development , Mastication/physiology , Animal Feed , Animals , Genomic Imprinting , Hardness , Male , Mandible/diagnostic imaging , Mice , Mice, Transgenic , Random Allocation , Stress, Mechanical , Weight-Bearing , X-Ray Microtomography
9.
J Toxicol Sci ; 34(5): 527-39, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19797861

ABSTRACT

A 4-week repeated dose oral toxicity study of phenobarbital (PB) sodium was conducted in F344 rats of both sexes at PB doses of 0.8, 8, and 80 mg/kg/day to fully elucidate its general toxicity including hematological changes. Both sexes in the 80 mg/kg/day group showed staggering gait, lacrimation, and/or sedation, which were more evident in the early stage of treatment. The body weight gain and food consumption were greater in these animals than in controls. Hematology revealed a significant reduction in the hematocrit (Ht), hemoglobin concentration (Hb), and erythrocyte count (RBC) in both sexes at 80 mg/kg/day, which was accompanied by a decrease in the cell mean Hb (CHCM) in mature erythrocytes with an increase in unsaturated iron binding capacity. Female rats also showed reduction in the CHCM in reticulocytes, content of hemoglobin per reticulocyte, and transferrin saturation. PB prolonged the activated partial thromboplastin time and inversely increased the platelet count with no evidence of platelet activation. Well-known toxic effects of PB on the liver and thyroid were observed in a dose-dependent manner, along with altered lipid, glucose, and electrolyte metabolism. The serum levels of PB increased dose-dependently, when examined in females received 8 and 80 mg/kg/day on day 1 and 28; there were no difference in C(max) and AUC(0-24) values between day 1 and day 28. These results indicated that PB has the potential to elicit multiple organ toxicity including an effect on the hematopoietic system. The hematological analysis provided evidence for hypochromic anemia, plausibly caused by the impairment of iron utility.


Subject(s)
Anemia, Hypochromic/chemically induced , Phenobarbital/toxicity , Administration, Oral , Animals , Body Weight/drug effects , Eating/drug effects , Female , Gait/drug effects , Iron/metabolism , Liver/drug effects , Liver/metabolism , Male , Organ Size/drug effects , Phenobarbital/administration & dosage , Phenobarbital/pharmacokinetics , Rats , Rats, Inbred F344 , Toxicity Tests , Urinalysis
10.
Bone ; 42(6): 1053-60, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18337200

ABSTRACT

Mandibular condylar cartilage can be distinguished from articular and growth cartilages of long bones based on several differences in morphology, physiology, and function between these structures. However, there is almost no information available on the types of genes that contribute to these differences. In this study, genes that were differentially expressed in mandibular condylar and growth cartilages in 1-week-old rats were investigated using fluorescent differential display (FDD) and laser microdissection (LMD). A number of genes were identified by FDD including chondromodulin-1 (ChM-1), which is known to be an angiogenesis inhibitor of endochondral ossification. ChM-1 expression was then compared with that of tenomodulin (TeM) in mandibular condylar and tibial cartilages of 1- and 5-week-old rats using real time PCR (RT-PCR), immunohistochemistry, and in situ hybridization. There was negligible detection of ChM-1 mRNA and protein in mandibular condylar cartilages compared to tibial cartilages of 1- and 5-week-old rats. On the other hand, TeM mRNA was more abundant in mandibular condylar cartilage than in tibial. These observations demonstrated that gene expression in mandibular condylar cartilage differed from other types of cartilage such as articular and growth ones.


Subject(s)
Cartilage, Articular/physiology , Gene Expression Regulation , Intercellular Signaling Peptides and Proteins/metabolism , Mandibular Condyle/anatomy & histology , Membrane Proteins/metabolism , Tibia/anatomy & histology , Animals , Cartilage, Articular/anatomy & histology , Gene Expression Profiling , In Situ Hybridization , Intercellular Signaling Peptides and Proteins/genetics , Lasers , Male , Mandibular Condyle/physiology , Membrane Proteins/genetics , Microdissection/methods , Rats , Rats, Sprague-Dawley , Tibia/physiology
11.
Carbohydr Res ; 343(4): 758-68, 2008 Mar 17.
Article in English | MEDLINE | ID: mdl-18179786

ABSTRACT

Despite the increasing attention being paid to the functions of glycoproteins, their structural analysis is still difficult and hinders functional investigations. Structural analysis of post-translationally modified proteins is thought to be achieved using methods frequently utilized in proteomics research; however, the same methods cannot be used for glycosylated proteins. One of the difficulties associated with the physiochemical properties of glycopeptides and peptides is that the detection of the former is considerably more difficult, because of the existence of glycoforms that increase molecular weight and reduces quantities of individual species. Thus, difficulties are often faced in finding glycopeptide(s) by using MS when analyzing peaks (or fractions) obtained after proteolytic digestion and HPLC. One simple yet difficult solution to this problem would be to develop a purification method that provides better resolution. Our intention has been to address this issue by using a combination of conventional methods. We found that a method consisting of a combination of rough fractionation using a reverse-phase cartridge column under acidic conditions and comparative RP-HPLC, where the two chromatograms obtained using phosphate and borate buffers under basic conditions were compared, is effective for MS-based structural analysis. The applicability of the method in glycoprotein analysis was examined using various samples including ribonuclease B (RNase B), IgG1, ovalbumin (OVA), and asialo fetuin (ASF). The results suggest that the method is useful in the analysis of glycoproteins.


Subject(s)
Chromatography, High Pressure Liquid/instrumentation , Chromatography, High Pressure Liquid/methods , Glycopeptides/analysis , Glycopeptides/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/instrumentation , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Acids/chemistry , Alkalies/chemistry , Amino Acid Sequence , Asialoglycoproteins/chemistry , Asialoglycoproteins/metabolism , Borates , Buffers , Fetuins , Humans , Hydrogen-Ion Concentration , Hydrophobic and Hydrophilic Interactions , Immunoglobulin G/chemistry , Immunoglobulin G/immunology , Molecular Sequence Data , Ovalbumin/chemistry , Ovalbumin/metabolism , Phosphates , Ribonucleases/chemistry , Ribonucleases/metabolism , Time Factors , Trypsin/metabolism , alpha-Fetoproteins/chemistry , alpha-Fetoproteins/metabolism
12.
J Nat Prod ; 67(12): 2070-2, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15620253

ABSTRACT

Derivatives of bufogenin isolated from the skin of the Chinese toad, Bufo bufo gargarizans Cantor ("Ch'an Su"), and several semisynthetic derivatives of 20beta,21beta-epoxy-resibufogenin (13) have been evaluated for interleukin-6 (IL-6) antagonistic activity due to their growth-inhibitory activities on IL-6-dependent MH-60 cells. Among the naturally derived compounds (1-17), 20S,21-epoxy-resibufogenin formate (1) showed potent inhibitory activity on the IL-6-dependent growth of MH-60 cells. Epoxide groups at both the C-14, C-15 and C-20, C-21 positions are required to exhibit this type of activity. Compounds acetylated at the C-16 position (7 and 9-11) showed a loss of activity. An oxo group at the C-3 position (8, 14, and 15) resulted in cytotoxicity for both cell lines. Stereochemistry is important for selectivity on suppression of IL-6 activity. Among the semisynthetic derivatives (18-25) of 13, compound 19, with an acetyl group introduced at the C-3 position in comparison to 13, demonstrated considerable growth inhibition of IL-6-dependent MH-60 cells.


Subject(s)
Bufanolides , Interleukin-6/antagonists & inhibitors , Animals , Bufanolides/chemistry , Bufanolides/isolation & purification , Bufanolides/pharmacology , Bufo bufo , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Mice , Molecular Structure , Stereoisomerism , Tumor Cells, Cultured
13.
Biochem Biophys Res Commun ; 323(3): 1096-102, 2004 Oct 22.
Article in English | MEDLINE | ID: mdl-15381112

ABSTRACT

While screening for novel IL-6 inhibitors, we synthesized 20S,21-epoxy-resibufogenin-3-acetate (ERBA). ERBA dose-dependently suppressed IL-6-induced cell growth with an IC(50) value of 5.3 microM and caused a parallel rightward shift of dose-response curves to IL-6. Analysis of data yields a pA2 of 5.83 and a slope of 0.99. ERBA did not affect IL-2-, IL-3-, and GCSF-dependent cell growth, or tumor necrosis factor alpha-induced growth suppression, nor did ERBA affect osteoclast formation induced by IL-11, leukemia inhibitory factor, and 1alpha,25-dihydroxyvitamin D(3). Receptor assay showed that ERBA dose-dependently suppressed IL-6 binding to IL-6 receptor (IL-6R). Furthermore, no band existing at the position of IL-6R in Western blots of ERBA-treated cells when stimulated with IL-6:ERBA suppresses IL-6 activity by blocking the binding of IL-6 to IL-6R. In an experimental model of colon 26-induced cancer cachexia, ERBA markedly inhibited body weight loss. ERBA is a specific small molecule with IL-6R-antagonist activity.


Subject(s)
Bone Marrow Cells/metabolism , Bufanolides/administration & dosage , Cachexia/drug therapy , Colonic Neoplasms/drug therapy , Receptors, Interleukin-6/antagonists & inhibitors , Receptors, Interleukin-6/metabolism , Skull/metabolism , Animals , Antineoplastic Agents/administration & dosage , Body Weight/drug effects , Bone Marrow Cells/cytology , Bone Marrow Cells/drug effects , Cachexia/etiology , Cachexia/pathology , Cell Line , Cell Line, Tumor , Coculture Techniques , Colonic Neoplasms/complications , Colonic Neoplasms/pathology , Female , Interleukin-6/pharmacology , Mice , Mice, Inbred BALB C , Skull/cytology , Skull/drug effects , Treatment Outcome
14.
DNA Res ; 10(1): 1-8, 2003 Feb 28.
Article in English | MEDLINE | ID: mdl-12693549

ABSTRACT

Gene regulatory networks elucidated from strategic, genome-wide experimental data can aid in the discovery of novel gene function information and expression regulation events from observation of transcriptional regulation among genes of known and unknown biological function. To create a reliable and comprehensive data set for the elucidation of transcription regulation networks, we conducted systematic genome-wide disruption expression experiments of yeast on 118 genes with known involvement in transcription regulation. We report several novel regulatory relationships between known transcription factors and other genes with previously unknown biological function discovered with this expression library. Here we report the downstream regulatory subnetworks for UME6 and MET28. The elucidated network topology among these genes demonstrates MET28's role as a nodal point between genes involved in cell division and those involved in DNA repair mechanisms.


Subject(s)
Genes, Regulator , Genomic Library , Transcription, Genetic , Algorithms , Oligonucleotide Array Sequence Analysis
15.
Toxicol Pathol ; 31(1): 87-98, 2003.
Article in English | MEDLINE | ID: mdl-12597452

ABSTRACT

Time-related changes in potential factors involved in hepatocarcinogenesis by DDT were investigated in a 4-week and a 2-year feeding studies of p,p'-DDT with F344 rats. In the 4-week study with males at doses of 50, 160, and 500 ppm, cell proliferation and gap junctional intercellular communication (GJIC) were examined after 1, 2, 3, 7, 14, and 28 days. Cell proliferation was enhanced within 3 days at any dose level, but returned to normal after 7 days, whereas GJIC was inhibited throughout the study. In the 2-year study with both sexes at doses of 5, 50, and 500 ppm, cell proliferation, GJIC, enzyme induction, and oxidative stress were investigated after 26, 52, 78, and 104 weeks. Males and females showed an inhibition of GJIC and increases in P450 isozymes (CYP2B1 and CYP3A2) in a dose-dependent manner at all time points, but no significant change in cell proliferation. Lipid peroxide for males at 50 and 500 ppm and 8-hydroxydeoxyguanosine for both sexes at 500 ppm were elevated throughout the study. Histologically, eosinophilic foci and hepatocellular adenomas increased in males at 50 ppm and both sexes at 500 ppm. Hepatocellular carcinomas also developed in males at 500 ppm. These results indicate that DDT may induce eosinophilic foci as a result of oxidative DNA damage and leads them to neoplasms in combination with its mitogenic activity and inhibitory effect on GJIC. Oxidative stress could be a key factor in hepatocarcinogenesis by DDT.


Subject(s)
DDT/toxicity , Liver Neoplasms, Experimental/chemically induced , Liver/drug effects , Precancerous Conditions/chemically induced , Animals , Carcinogenicity Tests , Cell Division/drug effects , Cytochrome P-450 Enzyme System/metabolism , Disease Progression , Dose-Response Relationship, Drug , Female , Gap Junctions/drug effects , Liver/enzymology , Liver/metabolism , Liver/pathology , Liver Neoplasms, Experimental/metabolism , Male , Oxidative Stress/drug effects , Precancerous Conditions/metabolism , Rats , Rats, Inbred F344
16.
Proc Natl Acad Sci U S A ; 99(23): 14728-33, 2002 Nov 12.
Article in English | MEDLINE | ID: mdl-12417753

ABSTRACT

IL-6 is a multifunctional cytokine involved in regulation of differentiation, antibody production, and growth of certain types of tumor cells. Its excessive production plays a major role in pathogenesis of multiple myeloma and postmenopausal osteoporosis. In the course of a screening program aimed at IL-6 inhibitor from microbial products, we found madindoline A (MDL-A) and madindoline B, which have a fuloindoline structure with diketocyclopentene bound to the methyl group. MDL-A has no cytotoxic activities. It inhibited only activities of both IL-6 and IL-11 without affecting the IL-6-specific signal transduction cascade, JAK2/STAT3. In a dose-dependent manner [(3)H]MDL-A binds to gp130, which is a signal transducing 130-kDa glycoprotein, but formation of the trimeric complex IL-6/IL-6 receptor/gp130 was not inhibited, suggesting that MDL-A suppresses dimerization of trimeric complexes. Not only did MDL-A markedly inhibit IL-6- and IL-11-induced osteoclastogenesis in vitro, but it also inhibited IL-6-stimulated serum amyloid A production and bone resorption in an experimental model of postmenopausal osteoporosis in vivo by a different mechanism from that of 17beta-estradiol. Here we show that MDL-A has a highly selective inhibitory effect on IL-6 and IL-11 activities by inhibiting a gp130 activity while suppressing bone loss in ovariectomized mice. MDL-A is anticipated as a lead compound for treatment of hormone-dependent postmenopausal osteoporosis, which has no serious side effects, and as a new mechanism of action, gp130 blocking.


Subject(s)
Bone Resorption/prevention & control , Bridged Bicyclo Compounds, Heterocyclic/pharmacology , Cytokines/pharmacology , Indoles/pharmacology , Receptors, Cytokine/antagonists & inhibitors , Animals , Cell Line , DNA-Binding Proteins/metabolism , Female , Growth Inhibitors/pharmacology , Humans , Interleukin-2/pharmacology , Interleukin-3/pharmacology , Interleukin-4/pharmacology , Interleukin-6/pharmacology , Interleukin-8 , Leukemia Inhibitory Factor , Lymphokines/pharmacology , Macrophages/drug effects , Macrophages/physiology , Mice , Mice, Inbred C3H , Mice, Inbred Strains , Nerve Growth Factor/pharmacology , Recombinant Proteins/pharmacology , STAT3 Transcription Factor , Signal Transduction/drug effects , Signal Transduction/physiology , Stereoisomerism , Trans-Activators/metabolism , Tumor Necrosis Factor-alpha/pharmacology
17.
J Pharmacol Exp Ther ; 303(1): 104-9, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12235239

ABSTRACT

Interleukin (IL)-6 is a key mediator in the regulation and coordination of the immune response and participates in pathogenesis of cancer cachexia, autoimmune disease, and postmenopausal osteoporosis. In the course of a screening program aimed at IL-6 inhibitor from natural products, we isolated 20S,21-epoxy-resibufogenin-3-formate (ERBF) from bufadienolide and examined the effect of ERBF on activities of various cytokines. ERBF dose dependently suppressed IL-6 activity and caused a parallel rightward shift of dose-response curves to IL-6 at concentrations of 0.03 to 10 ng/ml. Analysis of data yields a pA(2) of 5.12 and a slope of 0.99. Selectivity of ERBF on activity of cytokines was examined using cytokine-dependent cell lines. ERBF did not affect IL-2-dependent growth of CTLL-2 cells, IL-3-dependent growth of Baf3 cells, or tumor necrosis factor (TNF)alpha-induced growth suppression in TNFalpha-sensitive L929 cells. ERBF also did not affect IL-4-stimulated expression of FcepsilonR II receptor (CD23) in U-937 cells, the IL-8-induced chemotaxis of human neutrophils, or nerve growth factor-stimulated neuronal differentiation in PC-12 cells. In contrast, ERBF dose dependently suppressed IL-6-induced neuronal differentiation in PC-12 cells. Furthermore, ERBF suppressed only IL-6-induced osteoclast formation without affecting osteoclast formation induced by IL-11, leukemia inhibitory factor, and 1alpha,25-dihydroxyvitamin D(3). In receptor binding assay, unbound (free) IL-6 was increased in a dose-dependent manner by pretreatment with ERBF on IL-6 receptor (IL-6R), suggesting that ERBF suppresses binding of IL-6 to IL-6R. These results clearly indicate that ERBF is a novel specific small molecule to show IL-6 receptor antagonist activity.


Subject(s)
Bufanolides/pharmacology , Chemotaxis, Leukocyte/drug effects , Receptors, Interleukin-6/antagonists & inhibitors , Animals , Bone Marrow Cells/cytology , Bone Marrow Cells/drug effects , Cell Differentiation , Cell Division/drug effects , Cell Line , Coculture Techniques , Cytokines/pharmacology , Humans , Mice , Molecular Structure , Neurons/cytology , Neurons/drug effects , Osteoclasts/cytology , Osteoclasts/drug effects , PC12 Cells , Pheochromocytoma , Rats , Recombinant Proteins/antagonists & inhibitors , U937 Cells
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