Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 131
Filter
2.
J Dent Res ; 102(9): 1047-1057, 2023 08.
Article in English | MEDLINE | ID: mdl-37249312

ABSTRACT

Tooth enamel is generated by ameloblasts. Any failure in amelogenesis results in defects in the enamel, a condition known as amelogenesis imperfecta. Here, we report that mice with deficient autophagy in epithelial-derived tissues (K14-Cre;Atg7F/F and K14-Cre;Atg3F/F conditional knockout mice) exhibit amelogenesis imperfecta. Micro-computed tomography imaging confirmed that enamel density and thickness were significantly reduced in the teeth of these mice. At the molecular level, ameloblast differentiation was compromised through ectopic accumulation and activation of NRF2, a specific substrate of autophagy. Through bioinformatic analyses, we identified Bcl11b, Dlx3, Klk4, Ltbp3, Nectin1, and Pax9 as candidate genes related to amelogenesis imperfecta and the NRF2-mediated pathway. To investigate the effects of the ectopic NRF2 pathway activation caused by the autophagy deficiency, we analyzed target gene expression and NRF2 binding to the promoter region of candidate target genes and found suppressed gene expression of Bcl11b, Dlx3, Klk4, and Nectin1 but not of Ltbp3 and Pax9. Taken together, our findings indicate that autophagy plays a crucial role in ameloblast differentiation and that its failure results in amelogenesis imperfecta through ectopic NRF2 activation.


Subject(s)
Ameloblasts , Amelogenesis Imperfecta , Mice , Animals , Ameloblasts/metabolism , Amelogenesis Imperfecta/genetics , X-Ray Microtomography , NF-E2-Related Factor 2/metabolism , Amelogenesis/genetics , Mice, Knockout , Tumor Suppressor Proteins/metabolism , Repressor Proteins/metabolism
3.
J Dent Res ; 101(11): 1289-1298, 2022 10.
Article in English | MEDLINE | ID: mdl-35912790

ABSTRACT

The FaceBase Consortium, funded by the National Institute of Dental and Craniofacial Research of the National Institutes of Health, was established in 2009 with the recognition that dental and craniofacial research are increasingly data-intensive disciplines. Data sharing is critical for the validation and reproducibility of results as well as to enable reuse of data. In service of these goals, data ought to be FAIR: Findable, Accessible, Interoperable, and Reusable. The FaceBase data repository and educational resources exemplify the FAIR principles and support a broad user community including researchers in craniofacial development, molecular genetics, and genomics. FaceBase demonstrates that a model in which researchers "self-curate" their data can be successful and scalable. We present the results of the first 2.5 y of FaceBase's operations as an open community and summarize the data sets published during this period. We then describe a research highlight from work on the identification of regulatory networks and noncoding RNAs involved in cleft lip with/without cleft palate that both used and in turn contributed new findings to publicly available FaceBase resources. Collectively, FaceBase serves as a dynamic and continuously evolving resource to facilitate data-intensive research, enhance data reproducibility, and perform deep phenotyping across multiple species in dental and craniofacial research.


Subject(s)
Cleft Palate , Genomics , Cleft Palate/genetics , Humans , National Institutes of Health (U.S.) , Publications , Reproducibility of Results , United States
4.
J Dent Res ; 101(11): 1398-1407, 2022 10.
Article in English | MEDLINE | ID: mdl-35774010

ABSTRACT

Craniofacial structures change dynamically in morphology during development through the coordinated regulation of various cellular molecules. However, it remains unclear how these complex mechanisms are regulated in a spatiotemporal manner. Here we applied natural cubic splines to model gene and microRNA (miRNA) expression from embryonic day (E) 10.5 to E14.5 in the proximal and distal regions of the maxillary processes to identify spatiotemporal patterns of gene and miRNA expression, followed by constructing corresponding regulatory networks. Three major groups of differentially expressed genes (DEGs) were identified, including 3,927 temporal, 314 spatial, and 494 spatiotemporal DEGs. Unsupervised clustering further resolved these spatiotemporal DEGs into 8 clusters with distinct expression patterns. Interestingly, we found 2 clusters of differentially expressed miRNAs: 1 had 80 miRNAs monotonically decreasing and the other had 97 increasing across developmental stages. To evaluate the phenotypic relevance of these DEGs during craniofacial development, we integrated data from the CleftGeneDB database and constructed the regulatory networks of genes related to orofacial clefts. Our analysis revealed 2 hub miRNAs, mmu-miR-325-3p and mmu-miR-384-5p, that repressed cleft-related genes Adamts3, Runx2, Fgfr2, Acvr1, and Edn2, while their expression increased over time. On the contrary, 2 hub miRNAs, mmu-miR-218-5p and mmu-miR-338-5p, repressed cleft-related genes Pbx2, Ermp1, Snai1, Tbx2, and Bmi1, while their expression decreased over time. Our experiments indicated that these miRNA mimics significantly inhibited cell proliferation in mouse embryonic palatal mesenchymal (MEPM) cells and O9-1 cells through the regulation of genes associated with cleft palate and validated the role of our regulatory networks in orofacial clefts. To facilitate interactive exploration of these data, we developed a user-friendly web tool to visualize the gene and miRNA expression patterns across developmental stages, as well as the regulatory networks (https://fyan.shinyapps.io/facebase_shiny/). Taken together, our results provide a valuable resource that serves as a reference map for future research in craniofacial development.


Subject(s)
Cleft Lip , Cleft Palate , MicroRNAs , Animals , Cleft Lip/genetics , Cleft Palate/genetics , Core Binding Factor Alpha 1 Subunit , Gene Expression , Gene Expression Profiling , Gene Regulatory Networks/genetics , Mice , MicroRNAs/genetics , MicroRNAs/metabolism
5.
Transl Psychiatry ; 7(8): e1191, 2017 Aug 01.
Article in English | MEDLINE | ID: mdl-28763061

ABSTRACT

This corrects the article DOI: 10.1038/tp.2017.142.

6.
Transl Psychiatry ; 7(7): e1164, 2017 07 04.
Article in English | MEDLINE | ID: mdl-28675392

ABSTRACT

Late-onset Alzheimer's disease (AD) remains a medical mystery. Recent studies have linked it to impaired repair of aged neurons. Potential involvement of interleukin33 (IL33) in AD has been reported. Here we show that IL33, which was expressed by up to 75% astrocytes in the aged brains, was critical for repair of aged neurons. Mice lacking Il33 gene (Il33-/-) developed AD-like disease after 60-80 weeks, which was characterized by tau abnormality and a heavy loss of neurons/neurites in the cerebral cortex and hippocampus accompanied with cognition/memory impairment. We detected an abrupt aging surge in the cortical and hippocampal neurons at middle age (40 weeks). To counter the aging surge, wild-type mice rapidly upregulated repair of DNA double-strand breaks (DSBs) and autophagic clearance of cellular wastes in these neurons. Il33-/- mice failed to do so, but instead went on to develop rapid accumulation of abnormal tau, massive DSBs and abnormal autophagic vacuoles in these neurons. Thus, uncontrolled neuronal aging surge at middle age due to lack of IL33 resulted in neurodegeneration and late-onset AD-like symptome in Il33-/- mice. Our study also suggests that the aging surge is a time to search for biomarkers for early diagnosis of AD before massive neuron loss.


Subject(s)
Aging , Alzheimer Disease/metabolism , Interleukin-33/metabolism , Neurons/metabolism , tau Proteins/metabolism , Alzheimer Disease/pathology , Animals , Astrocytes/metabolism , Autophagy , Behavior, Animal , Cerebral Cortex/metabolism , Cerebral Cortex/pathology , DNA Repair , Mice, Inbred C57BL , Mice, Knockout , Neurons/pathology
7.
Oral Dis ; 22(1): 33-8, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26096083

ABSTRACT

The temporomandibular joint (TMJ) is a synovial joint essential for hinge and sliding movements of the mammalian jaw. Temporomandibular joint disorders (TMD) are dysregulations of the muscles or the TMJ in structure, function, and physiology, and result in pain, limited mandibular mobility, and TMJ noise and clicking. Although approximately 40-70% adults in the USA have at least one sign of TMD, the etiology of TMD remains largely unknown. Here, we highlight recent advances in our understanding of TMD in mouse models.


Subject(s)
Models, Animal , Models, Genetic , Temporomandibular Joint Disorders/genetics , Temporomandibular Joint/physiology , Animals , Disease Models, Animal , Facial Pain/physiopathology , Humans , Mandible , Mice , Range of Motion, Articular , Temporomandibular Joint/anatomy & histology , Temporomandibular Joint/physiopathology , Temporomandibular Joint Disorders/physiopathology , Transcription Factors
8.
Int J Oral Maxillofac Surg ; 43(7): 856-61, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24679852

ABSTRACT

The aim of this study was to determine whether mandibular setback by sagittal split ramus osteotomy (SSRO) influences swallowing function. The subjects were 14 patients with skeletal class III malocclusions who underwent setback surgery by SSRO. Morphological changes were studied on cephalograms, and swallowing function was evaluated by videofluorography before the operation (T0) and at 7-10 days (T1), 3 months (T2), and 6 months (T3) after surgery. The angle between nasion, sella, and hyoid bone (HSN) and the sella-hyoid distance had increased significantly at T1. The hyoid bone returned to the preoperative position at T2. There were no significant changes in the oropharyngeal space at any time. On videofluorographic assessment, lingual movement, soft palate movement, and epiglottic movement had decreased at T1, but all patients recovered at T2. The oral transit time was significantly longer at T1 than at T0. Our results confirm that SSRO influences swallowing function. Swallowing function appears to stabilize by 3 months after surgery.


Subject(s)
Deglutition/physiology , Malocclusion, Angle Class III/physiopathology , Malocclusion, Angle Class III/surgery , Osteotomy, Sagittal Split Ramus , Adult , Bone Plates , Cephalometry , Female , Fluoroscopy , Humans , Male , Malocclusion, Angle Class III/diagnostic imaging , Maxillofacial Abnormalities/diagnostic imaging , Maxillofacial Abnormalities/surgery , Orthodontics, Corrective , Treatment Outcome , Video Recording
9.
J Chem Phys ; 137(22): 22A527, 2012 Dec 14.
Article in English | MEDLINE | ID: mdl-23249064

ABSTRACT

The time-dependent density functional theory (TDDFT) is the leading computationally feasible theory to treat excitations by strong electromagnetic fields. Here the theory is applied to coherent optical phonon generation produced by intense laser pulses. We examine the process in the crystalline semimetal antimony (Sb), where nonadiabatic coupling is very important. This material is of particular interest because it exhibits strong phonon coupling and optical phonons of different symmetries can be observed. The TDDFT is able to account for a number of qualitative features of the observed coherent phonons, despite its unsatisfactory performance on reproducing the observed dielectric functions of Sb. A simple dielectric model for nonadiabatic coherent phonon generation is also examined and compared with the TDDFT calculations.

10.
J Dent Res ; 90(8): 981-7, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21593251

ABSTRACT

Programmed cell death, or apoptosis, is one of the fates of the medial edge epithelium (MEE) during palatal fusion. Transforming growth factor ß (Tgf-ß) signaling (such as Tgf-ß3) is required for the disappearance of the MEE, but the relationship between Tgf-ß3 and apoptosis remains unclear. Here we show that the Fas ligand (FasL)-Fas-Caspase extrinsic apoptosis pathway functions during palatal fusion in wild-type mice, but is not detectable in mice lacking Tgf-ß3 (Tgf-ß3 (-/-) ) or Tgfßr2 in the MEE (K14-Cre;Tgfbr2 (fl/fl)). Inhibition of the FasL-Fas system results in persistence of the midline epithelial seam (MES) and inhibition of caspase activity during palatal organ culture. Moreover, ectopic FasL protein induces apoptosis in MES of K14-Cre;Tgfbr2 (fl/fl) mice. Thus, we conclude that the FasL-Fas-caspase extrinsic apoptosis pathway is regulated by the Tgf-ß3 signaling cascade and is essential for palatal fusion during craniofacial development.


Subject(s)
Apoptosis/physiology , Caspases/metabolism , Fas Ligand Protein/metabolism , Palate, Hard/embryology , Transforming Growth Factor beta3/physiology , fas Receptor/metabolism , Animals , Caspase 3/metabolism , Caspase 8/metabolism , Cleft Palate/embryology , Epithelial Cells/metabolism , Epithelium/embryology , Gene Expression Regulation, Developmental , Mice , Mice, Knockout , Signal Transduction
11.
Oral Dis ; 17(8): 733-44, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21395922

ABSTRACT

Cleft palate, a malformation of the secondary palate development, is one of the most common human congenital birth defects. Palate formation is a complex process resulting in the separation of the oral and nasal cavities that involves multiple events, including palatal growth, elevation, and fusion. Recent findings show that transforming growth factor beta (TGF-ß) signaling plays crucial roles in regulating palate development in both the palatal epithelium and mesenchyme. Here, we highlight recent advances in our understanding of TGF-ß signaling during palate development.


Subject(s)
Palate/embryology , Signal Transduction/physiology , Transforming Growth Factor beta/physiology , Cleft Lip/embryology , Cleft Palate/embryology , Epithelium/embryology , Gene Expression/genetics , Humans , Mesoderm/embryology , Smad Proteins/physiology
12.
J Phys Condens Matter ; 22(38): 384212, 2010 Sep 29.
Article in English | MEDLINE | ID: mdl-21386546

ABSTRACT

We report a first-principles description for coherent phonon generation in diamond based on the time-dependent density functional theory. The time-dependent Kohn-Sham equation is solved in real time in order to calculate the electron dynamics in periodic solid exposed to an ultrashort laser pulse. We find that the calculated forces acting on ions are consistent with measurements as regards the selection rule and the dependence on the laser intensity.

13.
J Phys Condens Matter ; 21(6): 064224, 2009 Feb 11.
Article in English | MEDLINE | ID: mdl-21715926

ABSTRACT

We present a first-principles description for electron dynamics in crystalline SiO(2) induced by an optical field in both weak and intense regimes. We rely upon the time-dependent density-functional theory with the adiabatic local-density approximation, and a real-space and real-time method is employed to solve the time-dependent Kohn-Sham equation. The response calculation to a weak field provides us with information on the dielectric function, while the response to an intense field shows the optical dielectric breakdown. We discuss the critical threshold for the dielectric breakdown of crystalline SiO(2), in comparison with the results for diamond.

14.
Acta Neurochir (Wien) ; 144(3): 255-62; discussion 262-3, 2002 Mar.
Article in English | MEDLINE | ID: mdl-11956938

ABSTRACT

The efficacy of cerebrospinal fluid (CSF) shunting surgery for normal pressure hydrocephalus (NPH) is difficult to predict. The CSF removal test is useful but quantification of the results is difficult. A method to quantitatively measure cerebral blood flow (CBF) by single photon emission computed tomography twice within 30 min after double injection of N-isopropyl-p-[(123)I] iodoamphetamine using a background subtraction method to correct for the temporal profile was utilized in tandem with CSF removal via a lumbar spinal tube in 22 patients of NPH to produce maps of baseline CBF and quantitative CBF change after CSF removal. All 22 patients with NPH underwent ventriculoperitoneal shunting surgery and were divided into two groups according to improvement in clinical symptoms and signs (responder group, N=15; nonresponder group, N=7). Baseline clinical characteristics and baseline CBF values were not significantly different between the two groups. Regional and whole brain CBF changes in the responder group (range 98-105%, whole brain 101+/-39%) were significantly higher than those in the nonresponder group (range 41-48%, whole brain 46+/-40%) (P<0.01). Discrimination analysis showed that an increase of more than 80% in CBF after CSF removal was predictive of response to shunt surgery with 77% accuracy. This new quantitative CSF removal test could be useful for selecting good candidates for CSF shunting surgery among patients with NPH.


Subject(s)
Brain/blood supply , Hydrocephalus, Normal Pressure/surgery , Postoperative Complications/diagnostic imaging , Tomography, Emission-Computed, Single-Photon , Ventriculoperitoneal Shunt , Aged , Female , Humans , Hydrocephalus, Normal Pressure/diagnostic imaging , Hydrocephalus, Normal Pressure/physiopathology , Image Processing, Computer-Assisted , Iofetamine , Male , Middle Aged , Neurologic Examination , Patient Selection , Postoperative Complications/physiopathology , Prognosis , Regional Blood Flow/physiology , Spinal Puncture
15.
J Vet Med Sci ; 63(10): 1097-101, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11714025

ABSTRACT

In order to confirm the effects of matching of expressed feline major histocompatibility complex (FLA) class II DRB genotype on transplantation immunity in cats, skin-allogeneic transplantation was carried out between cats, in which DRB genes expressed were genotyped by the RT-PCR-RFLP method using group-specific primers. Duration until grafts were rejected was 14.63 +/- 1.69 days (mean +/- standard deviation) in the pairs that had the same type of subgroups, 7.25 +/- 0.71 days in the pairs that had one different type of subgroup and 6.88 +/- 0.35 days in the pairs that had two different types of subgroups. The duration of graft survival in the pairs with the same type of subgroups was significantly longer (P<0.01) than those in the pairs with different types. Although FLA components involved in transplantation immunity should not only be DRB genes, it was suggested that the expressed FLA-DRB genotype might associate with feline transplantation immunity, and that typing and matching of expressed FLA-DRB genes might be one of the important factors in the control of feline transplantation immunity.


Subject(s)
Cats/immunology , Genes, MHC Class II/immunology , Major Histocompatibility Complex/immunology , Skin Transplantation/immunology , Transplantation, Homologous/immunology , Animals , Cats/genetics , DNA, Complementary/chemistry , Female , Genes, MHC Class II/genetics , Genotype , Graft Rejection/genetics , Graft Rejection/immunology , Major Histocompatibility Complex/genetics , Male , Polymorphism, Restriction Fragment Length , RNA/chemistry , RNA/isolation & purification , Reverse Transcriptase Polymerase Chain Reaction/veterinary
16.
J Am Osteopath Assoc ; 101(9): 517-23, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11575038

ABSTRACT

The authors assessed the impact of osteopathic manipulative treatment (OMT) as an adjunct to standard psychiatric treatment of women with depression. Premenopausal women with newly diagnosed depression were randomly assigned to either control (osteopathic structural examination only; n = 9) or treatment group (OMT; n = 8). Both groups received conventional therapy consisting of the antidepressant paroxetine (Paxil) hydrochloride plus weekly psychotherapy for 8 weeks. Attending psychiatrists and psychologists were blinded to group assignments. No significant differences existed between groups for age or severity of disease. After 8 weeks, 100% of the OMT treatment group and 33% of the control group tested normal by psychometric evaluation. No significant differences or trends were observed between groups in levels of cytokine production (IL-1, IL-10, IL-2, IL-4, and IL-6) or in levels of anti-HSV-1, anti-HSV-2, and anti-EBV antibody. There was no pattern to the osteopathic manipulative structural dysfunctions recorded. The findings of this pilot study indicate that OMT may be a useful adjunctive treatment for alleviating depression in women.


Subject(s)
Depression/rehabilitation , Manipulation, Orthopedic/methods , Osteopathic Medicine/methods , Adult , Antidepressive Agents, Second-Generation/therapeutic use , Depression/classification , Depression/drug therapy , Depression/immunology , Double-Blind Method , Female , Humans , Middle Aged , Paroxetine/therapeutic use , Physical Examination/methods , Pilot Projects , Prospective Studies , Psychometrics , Psychotherapy , Treatment Outcome
17.
Am J Pathol ; 158(2): 663-72, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11159203

ABSTRACT

Previously we cloned and mapped a B120 gene to human chromosome 1p35-36.1 where possible suppressor genes for various neuroendocrine tumors including neuroblastoma have been mapped. Very recently, B120 was identified as a truncated form of p270, a putative human counterpart of SWI1. In the present study, expression of the B120 gene product was immunohistochemically investigated in 23 neuroblastomas. We also examined B120 expression in neural stem cells in developing brain and intact adrenal medulla. Four of 23 neuroblastomas strongly expressed B120 gene product in both cytoplasm and nucleus. The other neuroblastomas expressed B120 gene product in the nucleus; however, the intensity of staining was much weaker and equivalent to that in developing human brain stem cells in the subventricular region. B120 gene product was less strongly expressed in intact adrenal medulla. Subsequently, we performed loss of heterozygosity studies on 19 neuroblastomas using the polymorphic markers D1S195 and D1S511 located near the B120 gene. Loss of heterozygosity was observed in three of 19 tumors that abundantly expressed B120 protein. Furthermore, neuroblastoma cells were transfected with B120 expression vector. These transfected neuroblastoma cells adhered to each other and aggregated. Differential display experiments followed by reverse transcriptase-polymerase chain reaction and Northern blot analysis were performed and three molecules with altered expression in B120-transfected neuroblastoma cells were identified. One of three genes seemed to be a proliferation-related and cell cycle-related nucleolar protein, p120, encoding gene. We further characterized the genomic structure of B120. B120 appeared to be encoded by 17 exons in more than 20-kbp genomic DNA. The present findings contribute to understanding of the B120 gene, a truncated form of human SWII1, an approved term for which is SMARCF1, in normal cells and neuroblastomas.


Subject(s)
Neuroblastoma/genetics , Nuclear Proteins , Proteins/genetics , Transcription Factors/genetics , Base Sequence , Blotting, Northern , Blotting, Western , DNA, Complementary/chemistry , DNA, Complementary/genetics , DNA, Neoplasm/chemistry , DNA, Neoplasm/genetics , DNA, Recombinant , DNA-Binding Proteins , Exons , Female , Gene Expression Regulation, Neoplastic , Genes/genetics , Humans , Immunohistochemistry , Introns , Loss of Heterozygosity , Male , Molecular Sequence Data , Neuroblastoma/metabolism , Neuroblastoma/pathology , Plasmids/genetics , Proteins/analysis , RNA, Messenger/genetics , RNA, Messenger/metabolism , Radiation Hybrid Mapping , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNA , Tissue Distribution , Transfection , Tumor Cells, Cultured
18.
Pathol Res Pract ; 196(5): 293-8, 2000.
Article in English | MEDLINE | ID: mdl-10834385

ABSTRACT

Multinucleated giant cells (MGC) detected in the submucosal layer of human urinary bladder mainly associated with transitional cell carcinoma were examined immunohistochemically and ultrastructurally. The cases examined totaled 29, namely 14 cases with transitional cell carcinoma and another 15 cases mostly with malignancy in other organs. Histologically, MGC were smooth, irregular or dendritic in shape, and tended to increase in number in the vicinity of cancer or marked inflammation. They were consistently positive for not only vimentin, but also MB-2, and CD34, and were mostly positive for proliferating cell nuclear antigen (PCNA), but not MIB-1 (Ki-67) and HLA-DRalpha antigens. On occasion, antibodies to alpha-smooth muscle actin (alpha-SMA), muscle actin (M-actin), CD68 (KP-1) and alpha subunit of S-100 protein also yielded positive reactions. Interestingly, aggregated short bulbous processes were ultrastructurally observed on their surface in parts. These findings suggested that MGC in the submucosal layer of human urinary bladder were MB-2 and CD34-positive multipotential mesenchymal cells with no mitotic activity expressing fibroblastic (vimentin), myofibroblastic (alpha-SMA), or histiocytic (CD68) markers mostly in the vicinity of malignancy, and that these MGC were formed by fusion of mononuclear cells expressing identical markers with those of MGC. Further investigations are needed to clarify the exact function of MGC in human urinary bladder.


Subject(s)
Carcinoma, Transitional Cell/ultrastructure , Giant Cells/ultrastructure , Urinary Bladder Neoplasms/ultrastructure , Urinary Bladder/ultrastructure , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/analysis , Carcinoma, Transitional Cell/chemistry , Cell Nucleus/ultrastructure , Female , Giant Cells/chemistry , Humans , Immunoenzyme Techniques , Male , Microscopy, Electron , Middle Aged , Mucous Membrane/ultrastructure , Neoplasm Proteins/analysis , Organelles/ultrastructure , Urinary Bladder Neoplasms/chemistry
19.
Virchows Arch ; 436(4): 370-6, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10834541

ABSTRACT

Although the overexpression of cyclin D1 has been believed to play important roles in neoplastic transformation of some tumors, little is known about the function of cyclin D1 protein in carcinogenesis in human skin. A total of 307 patients with nonmelanocytic skin cancer, being 46 with Bowen's disease (BOD), 134 with squamous cell carcinoma (SCC) and 127 with basal cell carcinoma (BCC), were investigated immunohistochemically using monoclonal antibody to cyclin D1 by the LSAB method, to assess the expression of cyclin D1 in skin cancer including its precursors. The positive rates of cyclin D1 immunostaining in BOD, SCC and BCC were 63.0%, 69.4% and 54.3%, respectively. The positive rates in dysplasia adjoining BOD, SCC and BCC were 43.6%, 67.9% and 59.8%, respectively. In morphologically normal skin, however, only 2 cases, 1 of SCC and 1 of BCC, exhibited positive staining. These findings suggested that overexpression of cyclin D1 is an early event in dysplastic lesions of skin. Overexpression of cyclin D1 was related to sun exposure, especially in dysplasia of SCC. The score for cyclin D1 expression in dysplasia of BCC was correlated with age. Expression of cyclin D1 markedly increased from normal skin through dysplasia to BOD, but was not significantly related to the degree of SCC differentiation. These findings demonstrate that the effect of cyclin D1 overexpression is restricted to proliferation of cells, so that they gain a growth advantage, but their differentiation is not increased. Comparison with the results for p53 protein expression in these tumors, a significant correlation with cyclin D1 expression was found in dysplasia in BOD and SCC, and in patients with BCC who were less than 74 years old. These findings suggested the hypothesis that prior aberrant p53 expression may affect or regulate the overexpression of cyclin D1.


Subject(s)
Cyclin D1/metabolism , Skin Neoplasms/metabolism , Adult , Aged , Aged, 80 and over , Aging/metabolism , Bowen's Disease/metabolism , Bowen's Disease/pathology , Carcinoma, Basal Cell/metabolism , Carcinoma, Basal Cell/pathology , Carcinoma, Squamous Cell/metabolism , Carcinoma, Squamous Cell/pathology , Female , Humans , Immunohistochemistry/methods , Male , Middle Aged , Skin Neoplasms/pathology , Staining and Labeling , Sunlight
20.
Eur J Biochem ; 267(9): 2538-46, 2000 May.
Article in English | MEDLINE | ID: mdl-10785373

ABSTRACT

Some natural acetogenins are the most potent inhibitors of mitochondrial complex I. These compounds are characterized by two functional units [i.e. hydroxylated tetrahydrofuran (THF) and alpha, beta-unsaturated gamma-lactone ring moieties] separated by a long alkyl spacer. To elucidate which structural factors of acetogenins, including their active conformation, are crucial for the potent inhibitory activity we synthesized a novel bis-acetogenin and its analogues possessing two gamma-lactone rings connected to bis-THF rings by flexible alkyl spacers. The inhibitory potency of the bis-acetogenin with bovine heart mitochondrial complex I was identical to that of bullatacin, one of the most potent natural acetogenins. This result indicated that one molecule of the bis-acetogenin does not work as two reactive inhibitors, suggesting that a gamma-lactone and the THF ring moieties act in a cooperative manner on the enzyme. In support of this, either of the two ring moieties synthesized individually showed no or very weak inhibitory effects. Moreover, combined use of the two ring moieties at various molar ratios exhibited no synergistic enhancement of the inhibitory potency. These observations indicate that both functional units work efficiently only when they are directly linked by a flexible alkyl spacer. Therefore, some specific conformation of the spacer must be important for optimal positioning of the two units in the enzyme. Furthermore, the alpha,beta-unsaturated gamma-lactone, the 4-OH group in the spacer region, the long alkyl tail attached to the THF unit and the stereochemistry surrounding the hydroxylated bis-THF rings were not crucial for the activity, although these are the most common structural features of natural acetogenins. The present study provided useful guiding principles not only for simplification of complicated acetogenin structure, but also for further wide structural modifications of these molecules.


Subject(s)
Enzyme Inhibitors/pharmacology , Furans/pharmacology , Lactones/pharmacology , Mitochondria, Heart/drug effects , NADH, NADPH Oxidoreductases/antagonists & inhibitors , Oxygen/blood , Animals , Cattle , Drug Design , Electron Transport Complex I , Furans/chemical synthesis , Lactones/chemical synthesis , Magnetic Resonance Spectroscopy , Mass Spectrometry , Mitochondria, Heart/enzymology , Molecular Mimicry
SELECTION OF CITATIONS
SEARCH DETAIL