ABSTRACT
It is well known that a patient in clinical remission of visceral leishmaniasis (VL) remains immune to reinfection, which provides a rationale for the feasibility of a vaccine against this deadly disease. In earlier studies, observation of significant cellular responses in treated Leishmania patients as well as in hamsters against leishmanial antigens from different fractions led to its further proteomic characterization, wherein S-adenosyl-L-homocysteine hydrolase (AdoHcy) was identified as a helper type 1 (Th1) stimulatory protein. The present study includes immunological characterization of this protein, its cellular responses [lymphoproliferation, nitric oxide (NO) production and cytokine responses] in treated Leishmania-infected hamsters and patients as well as prophylactic efficacy against Leishmania challenge in hamsters and the immune responses generated thereof. Significantly higher cellular responses were noticed against recombinant L. donovani S-adenosyl-L-homocysteine hydrolase (rLdAdoHcy) compared to soluble L. donovani antigen in treated samples. Moreover, stimulation of peripheral blood mononuclear cells with rLdAdoHcy up-regulated the levels of interferon (IFN)-γ, interleukin (IL)-12 and down-regulated IL-10. Furthermore, vaccination with rLdAdoHcy generated perceptible delayed-type hypersensitivity response and exerted considerably good prophylactic efficacy (â¼70% inhibition) against L. donovani challenge. The efficacy was confirmed by the increased expression levels of inducible NO synthase and Th1-type cytokines, IFN-γ and IL-12 and down-regulation of IL-4, IL-10 and transforming growth factor (TGF)-ß. The results indicate the potentiality of rLdAdoHcy protein as a suitable vaccine candidate against VL.
Subject(s)
Adenosylhomocysteinase/immunology , Adenosylhomocysteinase/metabolism , Leishmaniasis Vaccines/immunology , Leishmaniasis, Visceral/immunology , Th1 Cells/enzymology , Adenosylhomocysteinase/administration & dosage , Adenosylhomocysteinase/genetics , Adolescent , Adult , Animals , Antigens, Protozoan/immunology , Child , Child, Preschool , Cricetinae , Cytokines/genetics , Female , Humans , Leishmania donovani/immunology , Leishmania donovani/isolation & purification , Leishmaniasis, Visceral/prevention & control , Leukocytes, Mononuclear/immunology , Lymphocyte Activation , Male , Nitric Oxide/biosynthesis , Proteomics , Protozoan Proteins/immunology , Th1 Cells/immunology , Vaccination , Vaccines, Synthetic/immunology , Young AdultABSTRACT
Enterococcus faecalis is a natural inhabitant of the human gastrointestinal tract. This bacterial species is subdominant in a healthy physiological state of the gut microbiota (eubiosis) in adults, but can become dominant and cause infections when the intestinal homeostasis is disrupted (dysbiosis). The relatively high concentrations of bile acids deoxycholate (DCA) and taurocholate (TCA) hallmark eubiosis and dysbiosis, respectively. This study aimed to better understand how E. faecalis adapts to DCA and TCA. We showed that DCA impairs E. faecalis growth and possibly imposes a continuous adjustment in the expression of many essential genes, including a majority of ribosomal proteins. This may account for slow growth and low levels of E. faecalis in the gut. In contrast, TCA had no detectable growth effect. The evolving transcriptome upon TCA adaptation showed the early activation of an oligopeptide permease system (opp2) followed by the adjustment of amino acid and nucleotide metabolisms. We provide evidence that TCA favors the exploitation of oligopeptide resources to fuel amino acid needs in limiting oligopeptide conditions. Altogether, our data suggest that the combined effects of decreased DCA and increased TCA concentrations can contribute to the rise of E. faecalis population during dysbiosis.
Subject(s)
Bile Acids and Salts , Enterococcus faecalis , Amino Acids/metabolism , Bile Acids and Salts/metabolism , Deoxycholic Acid/metabolism , Deoxycholic Acid/pharmacology , Dysbiosis , Enterococcus faecalis/genetics , Humans , Taurocholic Acid/metabolism , Taurocholic Acid/pharmacologyABSTRACT
Cabbage is a rich source of a number of bioactive compounds such as flavonoids, glucosinolates and their breakdown products which may have antibacterial, antioxidant and anticancer properties. Outer green leaves of York cabbage were extracted with 60% methanol, ethanol or acetone. Antibacterial activities of vacuum dried crude extracts were estimated against a number of Gram-positive and Gram-negative food spoilage and food pathogenic bacteria. The crude extracts showed a broad spectrum of antibacterial activities but 60% methanol extract exhibited the highest antibacterial effect. Complete growth inhibition for Listeria monocytogenes was achieved with an extract concentration of 1.4%, whereas a two-fold concentration was required to achieve a reduction of 75% and 64% for Salmonella abony and Pseudomonas aeruginosa, respectively. For Enterococcus faecalis methanolic extract showed a weak inhibition only (31%). The lower concentrations of methanolic extract from York cabbage prolonged the lag phase and reduced both the exponential growth rate and final population densities of the culture. Survival of the micro-organisms in presence of methanolic extract was mathematically modeled using Baranyi model equations.
Subject(s)
Anti-Bacterial Agents/pharmacology , Brassica/chemistry , Food Preservatives/pharmacology , Models, Biological , Plant Extracts/pharmacology , Plant Leaves/chemistry , Anti-Bacterial Agents/chemistry , Colony Count, Microbial , Food Preservatives/chemistry , Gram-Negative Bacteria/drug effects , Gram-Negative Bacteria/growth & development , Gram-Negative Bacteria/isolation & purification , Gram-Positive Bacteria/drug effects , Gram-Positive Bacteria/growth & development , Gram-Positive Bacteria/isolation & purification , Ireland , Kinetics , Methanol/chemistry , Microbial Viability/drug effects , Plant Extracts/chemistry , Solvents/chemistryABSTRACT
Involvement of cranial nerves is not uncommon in leprosy with trigeminal and facial nerves being commonly affected. Other cranial nerves can also be involved especially in longstanding cases of leprosy towards the lepromatous pole. Herein, we report a case of leprosy with multiple cranial neuropathy mimicking Melkerson Rosenthal syndrome.
Subject(s)
Cranial Nerve Diseases/etiology , Cranial Nerve Diseases/physiopathology , Leprosy/complications , Leprosy/diagnosis , Melkersson-Rosenthal Syndrome/diagnosis , Adult , Aged , Antitubercular Agents/therapeutic use , Cranial Nerve Diseases/drug therapy , Cranial Nerve Diseases/pathology , Diagnosis, Differential , Facial Nerve/physiopathology , Glossopharyngeal Nerve/physiopathology , Humans , Leprosy/classification , Leprosy/drug therapy , Male , Middle Aged , Treatment Outcome , Trigeminal Nerve/physiopathologyABSTRACT
A 54-year-old male presented with the history of headache and vomiting. MRI of the head showed right posterior temporal mass which was surgically excised. Histopathological examination revealed features of glioblastoma with pigmented cells. The pigment was demonstrated to be melanin which was confirmed by special stains and immunohistochemistry. This is the first description of glioblastoma with melanotic differentiation reported in the literature. The relevant literature is briefly reviewed.
Subject(s)
Brain Neoplasms/metabolism , Cell Transformation, Neoplastic/metabolism , Glioblastoma/metabolism , Melanins/metabolism , Brain Neoplasms/pathology , Brain Neoplasms/surgery , Cell Transformation, Neoplastic/pathology , Glioblastoma/pathology , Glioblastoma/surgery , Humans , Male , Middle Aged , Treatment OutcomeABSTRACT
Lagophthalmos is one of the well known complications of leprosy due to involvement of the facial nerve. Herein, we report three cases of bilateral lagophthalmos due to leprosy which presented to us within a span of just three months. In all these cases, lagophthalmos was not the presenting complaint and it was detected by the treating doctor during examination. This report is being presented to highlight the importance of cranial nerve examination in all cases of leprosy as at times early changes of lagophthalmos may go unnoticed by the patient.
Subject(s)
Ectropion/etiology , Leprosy, Borderline/complications , Leprosy, Tuberculoid/complications , Adult , Aged , Bell Palsy/complications , Bell Palsy/diagnosis , Ectropion/diagnosis , Facial Nerve/physiopathology , Humans , Leprosy, Borderline/diagnosis , Leprosy, Tuberculoid/diagnosis , Male , Middle AgedABSTRACT
BACKGROUND: Pharmacotherapy plays important role in the management of paediatric dental patients in the department of paediatric dentistry. Many children at their early age suffer from different kinds of dental conditions such as acute and chronic irreversible pulpitis, acute and chronic alveolar abscesses, dentoalveolar and vestibular abscesses, etc along with physiological tooth movement that requires professional help for dental treatment. Treatment of such conditions most frequently requires pharmacotherapy as an either adjunct to dental therapeutic procedure or as a monotherapy. OBJECTIVE: To assess the prescribing patterns vis-a-vis generic or trade name, generic class, dosage form, route, frequency, duration, number of drugs per patient, cost and indication of drug therapy, patterns of dental treatment and Frankl's behavioral rating. MATERIALS AND METHODS: Prescriptions of 200 paediatric dental patients undergoing dental treatment in the department of paediatric dentistry were analyzed prospectively for a period of six months in a dental teaching hospital. RESULTS: 133 (56.5%) patients were males and 87 (43.5%) females and age group 6-10 years was the most frequent group (70%, P = 0.0000000) and all the patients received pharmacotherapy. Total numbers of 357 drugs were prescribed. Out of them, 212 (59.4%, P = 0.0000008) were analgesic agents, 133 (37.3%) antimicrobial agents (AMAs) and 12 (3.3%) other drugs. Extended spectrum Penicillins were the most commonly prescribed (90.2%) AMA followed by Metronidazole (9.8%). 247 drugs (69.2%, P = 0.0000000) were prescribed by trade names. 60% (P = 0.0000002) drugs were prescribed in the form of tablet or capsule followed by syrup 37% and administered entirely through oral route. Percentage of patients receiving three drugs, two drugs and one drug was 13.5%, 56.5% (P = 0.0000000) and 30% respectively and one patient received on average 1.78 medicines. 133 patients (56.5%, P = 0.0000000) received both AMA and analgesic agent. Minimum to maximum number of days for pharmacotherapy were 2 to 15 and highest frequency was up to four times a day. Cost of medicines was in the range of 10-150 Nepalese Rupees. Chronic irreversible pulpitis was the commonest diagnosis (28%) and extraction (92.5%) was the commonest dental procedure. Frankl's behaviour rating showed that 78.5% (P = 0.0000000) patients had positive attitude towards the dental procedures. CONCLUSION: Findings of the study suggest that pharmacotherapy is the mainstay in therapy to treat the paediatric dental patients along with dental procedures either to control the dental pain or odontogenic infection. Age group 6-10 years, chronic irreversible pulpitis and dental extraction are the commonest age group, diagnosis and dental procedure respectively in the department of paediatric dentistry. Analgesic (non-steroidal anti-inflammatory drugs- Nimesulide, Ibuprofen and Paracetamol) and Amoxicillin are the most frequently prescribed drugs mostly in the solid dosage forms in trade names via oral route. Duration of pharmacotherapy ranges from 2 to 15 days with highest frequency being up to 4 times a day. Majority of the patients are manageable without any behavioural modification technique- physical or pharmacological.
Subject(s)
Drug Prescriptions/statistics & numerical data , Pediatric Dentistry , Practice Patterns, Physicians'/statistics & numerical data , Child , Drug Costs , Drug Prescriptions/economics , Female , Humans , Male , Nepal , Prospective StudiesABSTRACT
Iridate oxides display exotic physical properties that arise from the interplay between a large spin-orbit coupling and electron correlations. Here, we present a comprehensive study of the effects of hydrostatic pressure on the electronic transport properties of SrIrO3 (SIO), a system that has recently attracted a lot of attention as potential correlated Dirac semimetal. Our investigations on untwinned thin films of SIO reveal that the electrical resistivity of this material is intrinsically anisotropic and controlled by the orthorhombic distortion of the perovskite unit cell. These effects provide another evidence for the strong coupling between the electronic and lattice degrees of freedom in this class of compounds. Upon increasing pressure, a systematic increase of the transport anisotropies is observed. The anomalous pressure-induced changes of the resistivity cannot be accounted for by the pressure dependence of the density of the electron charge carriers, as inferred from Hall effect measurements. Moreover, pressure-induced rotations of the IrO6 octahedra likely occur within the distorted perovskite unit cell and affect electron mobility of this system.
ABSTRACT
Induction of cytochrome P1-450 has been linked to susceptibility to certain chemically induced cancers in mouse and man. Treatment of the human cell line MCF-7 with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) results in high levels of aryl hydrocarbon (benzo[a]pyrene) hydroxylase (P1-450) activity. This cell line was used to isolate a human P1-450 full-length complementary DNA (cDNA) clone. The cDNA is 2566 nucleotides in length, encodes a polyadenylated messenger RNA (2.8 kilobases in length), and has a continuous reading frame producing a protein with 512 residues (molecular weight, 58,151). The human P1-450 cDNA and protein are 63 percent and 80 percent similar to mouse P1-450 cDNA and protein, respectively. Whereas the mouse TCDD-inducible P-450 gene subfamily has two members (P1-450 and P3-450), the human TCDD-inducible gene subfamily appears to have only one gene (P1-450).
Subject(s)
Cytochrome P-450 Enzyme System/genetics , DNA/genetics , Dioxins/pharmacology , Polychlorinated Dibenzodioxins/pharmacology , Amino Acid Sequence , Animals , Base Sequence , Carcinogens/pharmacology , Cell Line , Cricetinae , Enzyme Induction , Humans , Mice , Nucleic Acid Hybridization , RabbitsABSTRACT
Roads are considered a sign of development bringing colossal benefits to community as socioeconomic and logistic facilitator. Yet, growth of road network has brought road crashes leading to civic pain from premature deaths of productive age group. In 2017, 16 citizens were killed and 53 injured every hour on Indian roads as per officially reported data, while a fair number go unreported. This is unacceptably high when compared with international standards. Risk correlates of road traffic injuries (RTIs) need to be redefined so as to form a continuum with other confounding factors that impact to take lives on road. Risk factors impacting RTIs vary from human components to the roles and responsibilities of healthcare stakeholders. We should have made roads safer for all citizens because a large percentage of population - children, pedestrians, cyclists, motorcyclists, and the elderly - are most vulnerable. A taskforce was set up by the Academy of Family Physicians of India to scientifically analyze the literature available to assess risks and put forward appropriate recommendations.
ABSTRACT
This corrects the article DOI: 10.1038/onc.2011.600.
ABSTRACT
This corrects the article DOI: 10.1038/onc.2010.491.
ABSTRACT
BACKGROUND: The phase II enzyme NAD(P)H :quinone oxidoreductase 1 (NQO1) catalyzes quinone detoxification, protecting cells from redox cycling, oxidative stress, mutagenicity, and cytotoxicity induced by quinones and its precursors. We have used NQO1(-/-) C57BL/6 mice to show that NQO1 protects them from skin cancer induced by the polycyclic aromatic hydrocarbon benzo[a]pyrene. Herein, we used NQO1(-/-) mice to investigate whether NQO1 also protects them against 7,12-dimethylbenz[a]anthracene (DMBA), where methyl substituents diminish primary quinone formation. METHODS: Dorsal skin of NQO1(-/-) or wild-type C57BL/6 mice was shaved. When tested as a complete carcinogen, DMBA (500 or 750 microg in 100 microL of acetone) alone was applied to the shaved area. When tested as a tumor initiator, DMBA (200 or 400 nmol in 100 microL of acetone) was applied to the shaved area; 1 week later, twice-weekly applications of phorbol 12-myristate 13-acetate (PMA)-10 microg dissolved in 200 microL of acetone-to the same area began and were continued for 20 weeks. Tumor development was monitored in all mice (12-15 per group). All statistical tests were two-sided. RESULTS: When DMBA (750 microg) was tested as a complete carcinogen, about 50% of the DMBA-treated NQO1(-/-) mice but no DMBA-treated wild-type mouse developed skin tumors. When DMBA (both concentrations) was used as a tumor initiator, NQO1(-/-) mice developed larger tumors at a greater frequency than their wild-type littermates. Twenty-three weeks after the first PMA treatment in the tumor initiator test, all 30 NQO1(-/-) mice given 400 nmol of DMBA had developed skin tumors, compared with 33% (10 of 30) of treated wild-type mice (P<.001). CONCLUSIONS: NQO1(-/-) mice are more susceptible to DMBA-induced skin cancer than are their wild-type littermates, suggesting that NQO1 may protect cells from DMBA carcinogenesis.
Subject(s)
Quinone Reductases/deficiency , Skin Neoplasms/enzymology , 9,10-Dimethyl-1,2-benzanthracene , Animals , Carcinogens , Disease Susceptibility/enzymology , Female , Male , Mice , Mice, Inbred C57BL , Skin Neoplasms/chemically inducedABSTRACT
Caffeic acid phenethyl ester (CAPE) is a phenolic antioxidant derived from the propolis of honeybee hives. CAPE was shown to inhibit the formation of intracellular hydrogen peroxide and oxidized bases in DNA of 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated HeLa cells and was also found to induce a redox change that correlated with differential growth effects in transformed cells but not the nontumorigenic parental ones. Mediated via the electrophile or human antioxidant response element (hARE), induction of the expression of NAD(P)H quinone oxidoreductase (NQO1) and glutathione S-transferase Ya subunit genes by certain phenolic antioxidants has been correlated with the chemopreventive properties of these agents. Here, we determined by Northern analysis that CAPE treatment of hepatoma cells stimulates NQO1 gene expression in cultured human hepatoma cells (HepG2), and we characterized the effects of CAPE treatment on the expression of a reporter gene either containing or lacking the hARE or carrying a mutant version of this element in rodent hepatoma (Hepa-1) transfectants. A dose-dependent transactivation of human hARE-mediated chloramphenicol acetyltransferase (cat) gene expression was observed upon treatments of the Hepa-1 transfectants with TPA, a known inducer, as well as with CAPE. The combined treatments resulted in an apparent additive stimulation of the reporter expression. To learn whether this activation of cat gene expression was effected by protein kinase C in CAPE-treated cells, a comparison was made of cat gene activity after addition of calphostin, a protein kinase C inhibitor. Calphostin reduced the cat gene induction by TPA but not by CAPE, suggesting that stimulation of gene expression in this system by these agents proceeds via distinct mechanisms. Band-shift experiments to examine binding of transactivator proteins from nuclear extracts of treated and untreated cells to a hARE DNA probe showed that TPA exposure increased the binding level. In contrast, binding of factors to this probe was inhibited after either in vivo treatment of cells with CAPE or in vitro addition of this compound to the nuclear extract. In view of the clear stimulation by CAPE of gene expression mediated by hARE, possible explanations of this result are discussed.
Subject(s)
Antioxidants/pharmacology , Caffeic Acids/pharmacology , Phenylethyl Alcohol/analogs & derivatives , Quinone Reductases/genetics , DNA/metabolism , Humans , Phenylethyl Alcohol/pharmacology , Tetradecanoylphorbol Acetate/pharmacology , Transcription Factor AP-1/metabolismABSTRACT
NAD(P)H:quinone oxidoreductase 1 (NQO1) is a flavoprotein that catalyzes the metabolic detoxification of quinones and their derivatives. This protects cells against quinone-induced oxidative stress, cytotoxicity, and mutagenicity. C57BL6 NQO1-/- mice, deficient in NQO1 RNA and protein, were generated in our laboratory. To investigate the role of NQO1 in chemical carcinogenesis, the dorsal skin of NQO1-deficient (NQO1-/-) and wild-type (NQO1+/+) mice were treated with a single dose of benzo(a)pyrene, followed by twice weekly applications of phorbol-12-myristate-13-acetate. The NQO1-/- mice showed a much higher frequency of skin tumor development when compared with their wild-type littermates. Interestingly, the male NQO1-/- mice were slower to develop skin tumors than their NQO1-/- female littermates. Histological analysis of the NQO1-/- tumors showed proliferative activity. These results demonstrate that NQO1 acts as an endogenous factor in protection against benzo(a)pyrene carcinogenicity.
Subject(s)
Benzo(a)pyrene/toxicity , Carcinogens/toxicity , Cocarcinogenesis , NAD(P)H Dehydrogenase (Quinone)/deficiency , Skin Neoplasms/chemically induced , Skin Neoplasms/enzymology , Animals , Benzo(a)pyrene/pharmacokinetics , Biotransformation , Carcinogens/pharmacokinetics , Disease Susceptibility , Female , Male , Mice , Mice, Inbred A , Models, Animal , NAD(P)H Dehydrogenase (Quinone)/genetics , NAD(P)H Dehydrogenase (Quinone)/metabolism , Skin/drug effects , Skin/enzymology , Tetradecanoylphorbol Acetate/toxicityABSTRACT
Antioxidant response element (ARE) and nuclear transcription factor Nrf2 are known to regulate expression and coordinated induction of NQO1 and other detoxifying enzyme genes in response to antioxidants and xenobiotics. A cytosolic inhibitor of Nrf2, INrf2, that retains Nrf2 in the cytoplasm, was cloned and sequenced. Treatment of cells with antioxidants and xenobiotics results in the release of Nrf2 from INrf2. Nrf2 then moves in the nucleus. This leads to the induction of ARE-mediated NQO1 and other detoxifying enzyme genes expression. INrf2 after dissociation from Nrf2 remains in the cytosol. Overexpression of INrf2 repressed ARE-mediated NQO1 gene expression. Deletion mapping of INrf2 revealed the requirement of KELCH domain (amino acid residues 361-597) and C-terminal region (amino acid residues 598-624) in retention of Nrf2 in the cytosol. Both these regions of INrf2 independently retained Nrf2 in the cytosol leading to the repression of ARE-mediated NQO1 gene expression. These results may indicate that two different regions of INrf2 interact with a single molecule of Nrf2 or two or more molecules of Nrf2 interact with a single molecule of INrf2. The transcription of Nrf2 and INrf2 did not change in response to antioxidants and xenobiotics. This indicated that INrf2 and/or Nrf2 might be post-transcriptionally modified in response to antioxidants and xenobiotics leading to the release of Nrf2 from INrf2 and induction of ARE-mediated NQO1 and other detoxifying enzyme genes expression.
Subject(s)
DNA-Binding Proteins/antagonists & inhibitors , Gene Expression Regulation, Enzymologic , Leucine Zippers , NAD(P)H Dehydrogenase (Quinone)/genetics , Nuclear Proteins/antagonists & inhibitors , Promoter Regions, Genetic , Proteins/physiology , Trans-Activators/antagonists & inhibitors , Amino Acid Sequence , Animals , Antioxidants/pharmacology , Base Sequence , DNA, Complementary , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Humans , Hydroquinones/pharmacology , Intracellular Signaling Peptides and Proteins , Kelch-Like ECH-Associated Protein 1 , Molecular Sequence Data , NF-E2-Related Factor 2 , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Proteins/genetics , Proteins/metabolism , Rats , Response Elements , Trans-Activators/genetics , Trans-Activators/metabolism , Tumor Cells, CulturedABSTRACT
Antioxidant response element (ARE)-mediated expression and coordinated induction of genes encoding detoxifying enzymes is one mechanism of critical importance to cellular protection against oxidative stress. In the present report, we demonstrate that nuclear transcription factors Nrf2 and Nrf1 associate with Jun (c-Jun, Jun-B and Jun-D) proteins to upregulate ARE-mediated expression and coordinated induction of detoxifying enzymes in response to antioxidants and xenobiotics. Nrf-Jun association/heterodimerization and binding to the ARE required unknown cytosolic factor(s). Nrf2 containing one mutated leucine in its leucine zipper region was more efficient in upregulation of ARE-mediated gene expression, as compared to Nrf1 with two mutated leucines.
Subject(s)
Collagenases/genetics , DNA-Binding Proteins/metabolism , Gene Expression Regulation , Glutathione Transferase/genetics , Leucine Zippers , NAD(P)H Dehydrogenase (Quinone)/genetics , Proto-Oncogene Proteins c-jun/metabolism , Trans-Activators/metabolism , Amino Acid Sequence , Animals , Antioxidants/pharmacology , Binding Sites , DNA-Binding Proteins/genetics , Humans , Leucine Zippers/genetics , Molecular Sequence Data , NF-E2-Related Factor 1 , NF-E2-Related Factor 2 , Nuclear Respiratory Factor 1 , Nuclear Respiratory Factors , Proto-Oncogene Proteins c-fos/genetics , Proto-Oncogene Proteins c-fos/metabolism , Proto-Oncogene Proteins c-jun/genetics , Rats , Sequence Homology, Amino Acid , Trans-Activators/genetics , Tumor Cells, Cultured , beta-Naphthoflavone/pharmacologyABSTRACT
The foreign chemical tetrachlorodibenzo-p-dioxin (TCDD) is known to interact with the aromatic hydrocarbon receptor and, in turn, activate transcription of the mouse P1450 and P3450 genes. Various lengths of DNA upstream from the human P1450 gene were inserted into the promoterless pSVO-cat prokaryotic expression vector and compared with mouse P1450 upstream sequences similarly treated. The constructs were cotransfected with pSV2-neo into human, mouse, and monkey liver- and nonliver-derived cell lines. After selection in G418, the transformed colonies were treated with control medium, TCDD, or, in some cases, cycloheximide. Pooled transformants were then assayed for chloramphenicol acetyltransferase activity. The data are consistent with the presence of several functional regulatory regions within the upstream DNA: a promoter region, a region that is negatively autoregulated, and a region further upstream that activates transcription and is dependent upon a functional aromatic hydrocarbon receptor. Compared with 1604 base pairs of human P1450 upstream sequences, 1646 base pairs of mouse P1450 upstream sequences exhibit an increased sensitivity to TCDD; this effect was found to require both trans-acting protein factors and cis-acting DNA elements. Our results demonstrate the successful interaction of mouse trans-acting factors with human P1450 upstream sequences and human trans-acting factors with mouse P1450 upstream sequences.
Subject(s)
Cytochrome P-450 Enzyme System/genetics , Genes, Regulator , Genes , Liver/metabolism , Cell Line , Genetic Vectors , Humans , Mutation , Organ Specificity , Plasmids , Transcription, Genetic , TransfectionABSTRACT
We have sequenced the human CYP1A2 (cytochrome P(3)450) gene, 1,906 basepairs (bp) of the 5' flanking region, and 113 bp of the 3' flanking region. The gene spans almost 7.8 kilobases, comprising seven exons and six introns. The transcriptional start site was determined by both primer extension and S1 mapping. Including the first noncoding exon of 55 bp, the entire mRNA is 3,121 bp in length, and the open reading frame, starting with nucleotide 10 of exon 2, encodes 515 amino acids (mol wt = 58,294). Between the human CYP1A2 and CYP1A1 (cytochrome P(1)450) genes, exons 2, 4, 6, and especially 5 are strikingly conserved in both nucleotide similarity and total number of bases. Alignment of the upstream sequences and exon 1 of human CYP1A2 with that of mouse or rat CYP1A2 revealed two possibly significant regions of similarity: 1) 68% in the approximately 150 bases immediately 5' from the mRNA cap site and 2) 80% identify between the human -841 to -758 segment and the mouse -1,529 to -1,439 segment. The canonical 5-bp box (CACGC), found upstream of all mammalian CYP1A1 genes to date and believed to interact with the inducer.aromatic hydrocarbon receptor complex, was not found on either strand in the 1,906 bp of the 5' flanking region of human CYP1A2. In contrast, alignment of the upstream sequences, exon 1, and intron 1 of human CYP1A1 with that of mouse or rat CYP1A1 revealed large, highly conserved regions. Conserved regions were found in intron 1 of the human, mouse, and rat CYP1A2 gene. These data suggest that the regulatory elements controlling the CYP1A2 gene might differ in location from those controlling the CYP1A1 gene. Among 12 human liver samples, striking differences (greater than 15-fold) in the 3.3-kilobase 1A2 mRNA levels were seen. This result may reflect significant genetic differences in constitutive and/or inducible CYP1A2 gene expression that could play an important role in individual risk of environmental toxicity or cancer.
Subject(s)
Cytochrome P-450 Enzyme System/genetics , Animals , Base Sequence , Blotting, Northern , Cloning, Molecular , Exons , Humans , In Vitro Techniques , Introns , Mice , Molecular Sequence Data , Polymorphism, Restriction Fragment Length , RNA, Messenger/analysis , Rats , Restriction Mapping , Sequence Homology, Nucleic AcidABSTRACT
A case of ossifying spinal lipoma is reported. The patient presented with a large swelling over the lumbar region with a dermal sinus in the centre. Imaging revealed an intradural lipoma connected with a large subcutaneous lipoma in which there was a prominent island of bone. The lipoma was excised and there were no postoperative neurological deficits. To the best of our knowledge, this is the first report of a spinal ossifying lipoma associated with a dermal sinus.