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1.
BJS Open ; 5(4)2021 07 06.
Article in English | MEDLINE | ID: mdl-34291287

ABSTRACT

BACKGROUND: Pancreatic neuroendocrine tumours (Pan-NETs) are rare tumours that often present with or develop liver metastases. The aim of this retrospective study was to evaluate liver surgery and thermal hepatic ablation (THA) of Pan-NET liver metastases and to compare the outcomes with those of a control group. METHOD: Patients with Pan-NET treated in Uppsala University Hospital and Sahlgrenska University Hospital from 1995-2018 were included. Patient records were scrutinized for baseline parameters, survival, treatment and complications. RESULTS: Some 108 patients met the criteria for inclusion; 57 patients underwent treatment with liver surgery or THA and 51 constitute the control group. Median follow-up was 3.93 years. Five-year survival in the liver surgery/THA group was 70.6 (95 per cent c.i. 0.57 to 0.84) per cent versus 42.4 (95 per cent c.i. 40.7 to 59.1) per cent in the control group (P = 0.016) and median survival was 9.1 (95 per cent c.i. 6.5 to 11.7) versus 4.3 (95 per cent c.i. 3.4-5.2) years. In a multivariable analysis, surgery or THA was associated with a decreased death-years rate (hazard ratio 0.403 (95 per cent c.i. 0.208 to 0.782, P = 0.007). CONCLUSION: Liver surgery and/or THA was associated with longer overall survival in Pan-NET with acceptable mortality and morbidity rates. These treatments should thus be considered in Pan-NET patients with reasonable tumour burden in an intent to alleviate symptoms and to improve survival.


Subject(s)
Liver Neoplasms , Pancreatic Neoplasms , Hepatectomy , Humans , Liver Neoplasms/surgery , Pancreatic Neoplasms/surgery , Retrospective Studies
2.
Br J Surg ; 105(9): 1128-1134, 2018 08.
Article in English | MEDLINE | ID: mdl-29663316

ABSTRACT

BACKGROUND: Traditionally, perforated diverticulitis with purulent peritonitis was treated with resection and colostomy (Hartmann's procedure), with inherent complications and risk of a permanent stoma. The DILALA (DIverticulitis - LAparoscopic LAvage versus resection (Hartmann's procedure) for acute diverticulitis with peritonitis) and other randomized trials found laparoscopic lavage to be a feasible and safe alternative. The medium-term follow-up results of DILALA are reported here. METHODS: Patients were randomized during surgery after being diagnosed with Hinchey grade III perforated diverticulitis at diagnostic laparoscopy. The primary outcome was the proportion of patients with one or more secondary operations from 0 to 24 months after the index procedure in the laparoscopic lavage versus Hartmann's procedure groups. The trial was registered as ISRCTN82208287. RESULTS: Forty-three patients were randomized to laparoscopic lavage and 40 to Hartmann's procedure. Patients in the lavage group had a 45 per cent reduced risk of undergoing one or more operations within 24 months (relative risk 0·55, 95 per cent c.i. 0·36 to 0·84; P = 0·012) and had fewer operations (ratio 0·51, 95 per cent c.i. 0·31 to 0·87; P = 0·024) compared with those in the Hartmann's group. No difference was found in mean number of readmissions (1·37 versus 1·50; P = 0·221) or mortality between patients randomized to laparoscopic lavage or Hartmann's procedure. Three patients in the lavage group and nine in the Hartmann's group had a colostomy at 24 months. CONCLUSION: Laparoscopic lavage is a better option for perforated diverticulitis with purulent peritonitis than open resection and colostomy.


Subject(s)
Colon/surgery , Diverticulitis, Colonic/surgery , Intestinal Perforation/surgery , Laparoscopy/methods , Peritoneal Lavage/methods , Peritonitis/therapy , Adult , Aged , Diverticulitis, Colonic/complications , Feasibility Studies , Female , Follow-Up Studies , Humans , Intestinal Perforation/complications , Length of Stay/trends , Male , Middle Aged , Peritonitis/etiology , Prospective Studies , Rupture, Spontaneous , Time Factors , Treatment Outcome
3.
Neurobiol Aging ; 32(12): 2314-5, 2011 Dec.
Article in English | MEDLINE | ID: mdl-20097445

ABSTRACT

We have established a novel transgenic rat line carrying human microtubule-associated protein Tau-40 with mutation P301L. hTau-40/P301L transgenic male and female rats were followed up to 2 years of age. The hTau-40/P301L rats expressed human tau mRNA and protein in the limbic cortex and associated white matter, hippocampus and spinal cord. With increasing age, the staining density for phosphorylated tau increased in all these areas. Neither silver stains nor Fluoro-Jade staining indicated the presence of dying neurons, or axonal degeneration, and there was no evidence of increased gliosis or inflammation. However, some neurons did display dendritic abnormalities, and immunoblots revealed the presence of sarcosyl insoluble tau. A large test battery revealed no behavioral abnormalities in these rats, except a mild hyperactivity in the elevated plus maze. In conclusion, this transgenic tau rat may be a useful model for 'pretangle' pathology, although in this study conditions were not sufficient to induce significant neuronal loss or behavioral deficits.


Subject(s)
Brain Chemistry/genetics , Models, Animal , Mutation/genetics , tau Proteins/chemistry , tau Proteins/genetics , Animals , Female , Hippocampus/chemistry , Hippocampus/metabolism , Humans , Limbic System/chemistry , Limbic System/metabolism , Male , Rats , Rats, Transgenic , Spinal Cord/chemistry , Spinal Cord/metabolism
4.
Inflamm Res ; 54(5): 194-203, 2005 May.
Article in English | MEDLINE | ID: mdl-15953991

ABSTRACT

OBJECTIVE: Our aim was to study how different SERMs modulate the inflammatory responses induced by lipopolysaccharide (LPS) or unmethylated CpG-oligonucleotides in mouse and rat microglial cells. MATERIALS AND METHODS: Inflammatory responses of mouse N9 microglial cells and rat primary hippocampal microglia to lipopolysaccharide (LPS) exposure were recorded by the secretion of nitric oxide (NO) and cytokine IL-6 in two models where SERM was added either 24 h before LPS addition or simultaneously or even after the LPS exposure. The responses of 17beta-estradiol, tamoxifen, raloxifene and ICI 182.780 were compared. Responses were recorded by ELISA, Northern and EMSA assays. RESULTS: SERMs but not 17beta-estradiol induced a significant, concentration-dependent anti-inflammatory response both in rat primary microglial cells and in mouse N9 microglial cells. The response was observed both in NO and IL-6 secretion as well as in total IL-6 mRNA expression. We have recently observed that histone deacetylase (HDAC) inhibitors can potentiate the LPS-induced inflammatory response. Raloxifene and tamoxifen inhibited the potentiation of LPS response induced by trichostatin A, an HDAC inhibitor, in N9 microglia. A SERM-induced anti-inflammatory response was observed in acute models where SERM was added simultaneously or even up to 6 h later than LPS exposure. In contrast, the pretreatment of N9 microglia with tamoxifen or raloxifene for 30 h before LPS exposure did not provide any protection against the LPS response. We also observed that the raloxifene-induced protection in N9 microglia was connected to a decline of LPS-induced DNA binding activity of AP-1 but not that of NF-kappaB transcription factors. CONCLUSIONS: Our results show that tamoxifen, raloxifene and ICI 182.780 induce an anti-inflammatory response in acute models of mouse and rat microglial cells. It seems that this response is not estrogen receptor-mediated but, probably, is attributable to some SERM-induced modulation of LPS-activated pro-inflammatory signalling cascades.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Inflammation/drug therapy , Microglia/pathology , Selective Estrogen Receptor Modulators/pharmacology , Animals , Astrocytes/cytology , Blotting, Northern , Cell Proliferation , Cells, Cultured , CpG Islands , DNA/metabolism , Dose-Response Relationship, Drug , Down-Regulation , Enzyme-Linked Immunosorbent Assay , Estradiol/analogs & derivatives , Estradiol/metabolism , Estradiol/pharmacology , Fulvestrant , Hippocampus/cytology , Histone Deacetylase Inhibitors , Histone Deacetylases/metabolism , Humans , Interleukin-6/blood , Interleukin-6/metabolism , L-Lactate Dehydrogenase/metabolism , Lipopolysaccharides/metabolism , Mice , Microglia/metabolism , Nitric Oxide/metabolism , Oligonucleotides/metabolism , Protein Binding , RNA, Messenger/metabolism , Raloxifene Hydrochloride/pharmacology , Rats , Rats, Wistar , Tamoxifen/pharmacology , Time Factors
5.
J Am Acad Child Adolesc Psychiatry ; 38(1): 34-9, 1999 Jan.
Article in English | MEDLINE | ID: mdl-9893414

ABSTRACT

BACKGROUND: Very little is known about attention-deficit hyperactivity disorder (ADHD) in African-American children, and although the familial transmission of ADHD has been well established in white samples, prior work has not evaluated this feature of ADHD in African-American families. METHOD: Subjects were 37 first-degree relatives of children with DSM-III-R-defined ADHD and 52 first-degree relatives of non-ADHD comparison children matched for ethnicity, age, and gender. DSM-III-R-based structured interviews (modified to include DSM-IV diagnoses) provided the basis for psychiatric diagnoses in relatives. RESULTS: The risks for both DSM-III-R and DSM-IV ADHD were significantly greater in first-degree relatives of ADHD probands than in relatives of controls. In addition, the relatives of ADHD probands also were at higher risk for oppositional defiant disorder, antisocial personality disorder, major depression, generalized anxiety, and substance use disorders. CONCLUSIONS: These results suggest that ADHD and related disorders are familial in African-Americans. Further work is needed to confirm the familial transmission of ADHD in African-American children and to explore the role of genetics as well as environmental factors in the transmission of the disorder.


Subject(s)
Attention Deficit Disorder with Hyperactivity/ethnology , Black or African American/psychology , Family/psychology , Adolescent , Black or African American/statistics & numerical data , Attention Deficit Disorder with Hyperactivity/genetics , Black People , Case-Control Studies , Child , Female , Humans , Logistic Models , Male , Pilot Projects , United States/epidemiology
6.
Am J Psychiatry ; 155(5): 696-8, 1998 May.
Article in English | MEDLINE | ID: mdl-9585726

ABSTRACT

OBJECTIVE: The authors' goal was to explore the nature of attention deficit hyperactivity disorder (ADHD) in African American children, which has received scant attention by psychiatric researchers. METHOD: Subjects were 19 African American children with DSM-III-R ADHD and 24 African American children without ADHD. Ethnically sensitive methods were used to evaluate the children comprehensively. The findings were compared with those from an earlier study of Caucasian children with ADHD. RESULTS: African American children with ADHD had higher levels of psychiatric disorders other than ADHD than did African American children who did not have ADHD. CONCLUSIONS: Among African American children, ADHD may be characterized by a narrower pattern of psychiatric comorbidity and dysfunction than has been observed in Caucasians. Given the small number of subjects studied, these findings are preliminary and must be replicated to confirm their validity.


Subject(s)
Attention Deficit Disorder with Hyperactivity/diagnosis , Black or African American/statistics & numerical data , Adolescent , Age Factors , Attention Deficit Disorder with Hyperactivity/epidemiology , Child , Comorbidity , Humans , Mental Disorders/diagnosis , Mental Disorders/epidemiology , Psychiatric Status Rating Scales/statistics & numerical data , Reproducibility of Results , White People/statistics & numerical data
7.
Immunity ; 7(5): 591-9, 1997 Nov.
Article in English | MEDLINE | ID: mdl-9390683

ABSTRACT

A major issue is whether surface expression of the pre-TCR is necessary for signaling the development of immature thymocytes. To address this question, we generated transgenic mice expressing a TCRbeta chain that had a strong endoplasmic reticulum (ER) retrieval signal (TCRbetaER) and that was expressed intracellularly but failed to reach the cell surface. In TCRbetaER transgenic mice, there was a failure of allelic exclusion. Also, the transgene failed to rescue the developmental defects observed in TCRbeta-null mice. In contrast, TCRbeta transgenes with a mutant ER retrieval sequence or lacking this sequence signaled efficient allelic exclusion and suppressed the TCRbeta-/- defect. These data show that exit of the pre-TCR from the ER/cis-Golgi is required for progression through the double-negative thymocyte checkpoint.


Subject(s)
Endoplasmic Reticulum, Rough/metabolism , Gene Rearrangement, beta-Chain T-Cell Antigen Receptor , Golgi Apparatus/metabolism , Receptors, Antigen, T-Cell, alpha-beta/metabolism , T-Lymphocytes/cytology , Thymus Gland/cytology , Alleles , Amino Acid Sequence , Animals , Calcium/metabolism , Cell Differentiation , Cell Division , Gene Expression Regulation, Developmental , Humans , Mice , Mice, Transgenic , Molecular Sequence Data , Protein Processing, Post-Translational , Receptors, Antigen, T-Cell, alpha-beta/genetics
8.
J Am Acad Child Adolesc Psychiatry ; 36(11): 1552-9; discussion 1559-60, 1997 Nov.
Article in English | MEDLINE | ID: mdl-9394940

ABSTRACT

OBJECTIVE: Although a small literature of case reports suggests that mania co-occurs with pervasive developmental disorder (PDD), little is known about this overlap. The authors systematically investigated the overlap between mania and PDD in a consecutive sample of referred youths, examining its prevalence and correlates. It was hypothesized that children with PDD plus manic features have both disorders. METHOD: Subjects were consecutively referred children meeting diagnostic criteria on structured interview for PDD without mania (n = 52), the comorbid condition PDD + mania (n = 14), and mania without PDD (n = 114). All subjects were evaluated using a comprehensive diagnostic battery that included assessment of psychopathology (structured diagnostic interview and Child Behavior Checklist), cognition, and functioning. RESULTS: Of the 727 referred children, 52 met criteria for PDD, 114 met criteria for mania, and 14 met criteria for both. The 14 children with both PDD + mania represented 21% of the PDD subjects and 11% of all manic subjects. Clinical characteristics of PDD were similar in PDD subjects with and without mania, and manic features were similar in manic children with and without PDD. CONCLUSIONS: Children with PDD and mania may suffer from two disorders. Comorbid mania among patients with PDD may be more common than previously thought. Identification of the comorbid condition may have important therapeutic and scientific implications.


Subject(s)
Bipolar Disorder/epidemiology , Child Development Disorders, Pervasive/epidemiology , Bipolar Disorder/psychology , Child , Child Development Disorders, Pervasive/psychology , Comorbidity , Female , Humans , Male , Prevalence
9.
Cell ; 89(5): 765-71, 1997 May 30.
Article in English | MEDLINE | ID: mdl-9182764

ABSTRACT

We have generated Cbfa1-deficient mice. Homozygous mutants die of respiratory failure shortly after birth. Analysis of their skeletons revealed an absence of osteoblasts and bone. Heterozygous mice showed specific skeletal abnormalities that are characteristic of the human heritable skeletal disorder, cleidocranial dysplasia (CCD). These defects are also observed in a mouse Ccd mutant for this disease. The Cbfa1 gene was shown to be deleted in the Ccd mutation. Analysis of embryonic Cbfa1 expression using a lacZ reporter gene revealed strong expression at sites of bone formation prior to the earliest stages of ossification. Thus, the Cbfa1 gene is essential for osteoblast differentiation and bone formation, and the Cbfa1 heterozygous mouse is a paradigm for a human skeletal disorder.


Subject(s)
Bone Development/genetics , Cleidocranial Dysplasia/genetics , Neoplasm Proteins , Osteoblasts/pathology , Transcription Factors/genetics , Animals , Cell Differentiation/genetics , Core Binding Factor Alpha 1 Subunit , Gene Deletion , Gene Targeting , Humans , Mice , Mice, Mutant Strains , Syndrome
10.
J Am Acad Child Adolesc Psychiatry ; 36(1): 21-9, 1997 Jan.
Article in English | MEDLINE | ID: mdl-9000777

ABSTRACT

OBJECTIVE: To evaluate whether attention-deficit hyperactivity disorder (ADHD) is a risk factor for psychoactive substance use disorders (PSUD), attending to issues of psychiatric comorbidity, family history, and adversity. METHOD: Using assessments from multiple domains, the authors examined 140 ADHD and 120 normal control subjects at baseline and 4 years later. Drug and alcohol abuse and dependence were operationally defined. RESULTS: No differences were detected in the rates of alcohol or drug abuse or dependence or in the rates of abuse of individual substances between the groups; both ADHD and control probands had a 15% rate of PSUD. Conduct and bipolar disorders predicted PSUD, independently of ADHD status. Family history of substance dependence and antisocial disorders was associated with PSUD in controls but less clearly so in ADHD probands. Family history of ADHD was not associated with risk for PSUD. ADHD probands had a significantly shorter time period between the onsets of abuse and dependence compared with controls (1.2 years versus 3 years, p < .01). CONCLUSIONS: Adolescents with and without ADHD had a similar risk for PSUD that was mediated by conduct and bipolar disorder. Since the risk for PSUD has been shown to be elevated in adults with ADHD when compared with controls, a sharp increase in PSUD is to be expected in grown-up ADHD children during the transition from adolescence to adulthood.


Subject(s)
Attention Deficit Disorder with Hyperactivity/complications , Substance-Related Disorders/epidemiology , Adolescent , Adult , Bipolar Disorder/complications , Case-Control Studies , Child , Child Behavior Disorders/complications , Cohort Studies , Family Health , Humans , Male , Regression Analysis , United States/epidemiology
11.
Nature ; 368(6473): 760-4, 1994 Apr 21.
Article in English | MEDLINE | ID: mdl-8152489

ABSTRACT

The ubiquitous Ca(2+)-binding protein calmodulin (CaM) is a key protein in Ca2+ homeostasis and activation of eukaryotic cells. CaM is the molecular link between free Ca2+ in the cell and the inhibition, or activation, of numerous enzymes. Many nuclear functions are under Ca2+/CaM control, and some transcriptional activators are known to be Ca2+ modulated indirectly through Ca2+/CaM-dependent protein kinases. But Ca2+/CaM has not yet been found to directly modulate any transcription factor or other DNA-binding protein. Transcription factors of the basic-helix-loop-helix (bHLH) group are important regulators in numerous systems. Here we report that binding of Ca(2+)-loaded CaM to the bHLH domains of several bHLH proteins directly inhibits their DNA binding. Other bHLH proteins are either less sensitive or resistant. Ca2+ ionophore selectively inhibits transcriptional activation by Ca2+/CaM-sensitive bHLH proteins in vivo, implying that Ca2+ can directly influence transcription through differential CaM inhibition of bHLH domains.


Subject(s)
Calcium/physiology , Calmodulin/physiology , Helix-Loop-Helix Motifs/physiology , Transcription Factors/physiology , Transcription, Genetic/physiology , Animals , Base Sequence , Calcium-Calmodulin-Dependent Protein Kinase Type 2 , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Cattle , Cell Line , Cross-Linking Reagents/pharmacology , DNA/metabolism , DNA-Binding Proteins/physiology , Glutaral/pharmacology , Humans , Ionomycin/pharmacology , Mice , Molecular Sequence Data , Protein Binding
12.
J Biol Chem ; 268(29): 21946-54, 1993 Oct 15.
Article in English | MEDLINE | ID: mdl-8408051

ABSTRACT

Binding sites for SL3-3 enhancer factor 1 (SEF1) are important for the transcriptional activity in T lymphocytes and the tumorigenicity of SL3-3 murine leukemia virus. SEF1 is also implicated in the activity of many other leukemia, lymphoma, and sarcoma virus enhancers, and enhancers of genes for T cell receptor-CD3 subunits. We have purified several proteins binding to SEF1 sites from bovine thymus using a five-step purification procedure. The proteins migrated as 19 distinct bands representing molecular masses from 23 kDa to about 200 kDa in SDS-polyacrylamide gel electrophoresis. Ten DNA binding proteins, with molecular masses between 23 and 67 kDa, could be isolated after separation by SDS-polyacrylamide gel electrophoresis. The DNA binding specificities of these proteins were similar and corresponded to that of the SEF1 binding activity in nuclear extracts. Each of these isolated SEF1 proteins also bound to the essential delta-E3 element of the human T cell receptor delta enhancer. Antibodies against one SEF1 protein only reacted with the protein used for immunization, which indicates a limited homology between at least some SEF1 proteins. We also present data suggesting that SEF1 proteins exist in multiple forms with differences in their DNA binding specificity, and that high affinity DNA binding of the SEF1 proteins requires protein phosphorylation.


Subject(s)
DNA-Binding Proteins/isolation & purification , Enhancer Elements, Genetic , Neoplasm Proteins , T-Lymphocytes/metabolism , Transcription Factors/isolation & purification , Transcription, Genetic , Animals , Base Sequence , Binding Sites , CD3 Complex/metabolism , Cattle , DNA/metabolism , DNA-Binding Proteins/metabolism , Molecular Sequence Data , Phosphorylation , Receptors, Antigen, T-Cell/metabolism , Thymus Gland/metabolism , Transcription Factors/metabolism
13.
Nucleic Acids Res ; 20(24): 6495-9, 1992 Dec 25.
Article in English | MEDLINE | ID: mdl-1480471

ABSTRACT

A family of proteins, denoted SL3-3 enhancer factor 1 (SEF1), interacts with DNA sequences in the T cell specific enhancer of SL3-3 murine leukemia virus and in the enhancers of several other viruses. A putative SEF1 binding site was also identified in the T cell specific enhancer of the gene encoding the human T cell antigen receptor (TcR) associated CD3-epsilon polypeptide. In this study we show that the identified sequence is a strong SEF1 binding site, and that purified SEF1 proteins bind specifically to the sequence. We report also that the SEF1 binding site is important for T cell specific activation of transcription by the CD3-epsilon enhancer. We show that SEF1 binding sites are present also in the T cell specific enhancers of other subunits of the TcR-CD3 complex, and that SEF1 proteins appear to play a central role in the T cell specific expression of this set of enhancers.


Subject(s)
CD3 Complex/genetics , DNA-Binding Proteins/metabolism , Enhancer Elements, Genetic , Neoplasm Proteins , Receptors, Antigen, T-Cell/genetics , T-Lymphocytes/immunology , Transcription Factors/metabolism , Animals , Base Sequence , Cattle , Cell Line , Cell Nucleus/metabolism , Electrophoresis, Polyacrylamide Gel , Humans , Mice , Molecular Sequence Data , Mutagenesis, Site-Directed , Protein Binding , Sequence Homology, Nucleic Acid , Thymus Gland/immunology
14.
J Virol ; 65(11): 6084-93, 1991 Nov.
Article in English | MEDLINE | ID: mdl-1681116

ABSTRACT

A family of nuclear proteins, designated SL3-3 enhancer factors 2 (SEF2), were found to interact with an Ephrussi box-like motif within the glucocorticoid response element in the enhancer of the murine leukemia virus SL3-3. Mutation of the DNA sequence decreased the basal enhancer activity in various cell lines. The important nucleotides for binding of SEF2 are conserved in most type C retroviruses. Various cell types displayed differences both in the sets of SEF2-DNA complexes formed and in their amounts. A cDNA which encoded a protein that interacted specifically with the SEF2-binding sequence was isolated from human thymocytes. The nucleotide sequence specificity of the recombinant protein, expressed in Escherichia coli, corresponded to that of at least one of the nuclear SEF2 proteins. Sequence analysis of the cDNA revealed that it belongs to the basic helix-loop-helix class of DNA-binding proteins. Several mRNA transcripts of different sizes were identified. Molecular analysis of cDNA clones revealed multiple related mRNA species containing alternative coding regions, which are most probably a result of differential splicing.


Subject(s)
DNA-Binding Proteins , Enhancer Elements, Genetic , Leukemia Virus, Murine/genetics , Nerve Tissue Proteins , Nuclear Proteins/metabolism , Receptors, Glucocorticoid/metabolism , Trans-Activators/metabolism , Transcription Factors , Transcription, Genetic , Amino Acid Sequence , Animals , Base Sequence , Basic Helix-Loop-Helix Leucine Zipper Transcription Factors , Binding Sites , Blotting, Northern , Cell Line , Cloning, Molecular/methods , Escherichia coli/genetics , HeLa Cells , Humans , Mice , Molecular Sequence Data , Molecular Weight , Oligodeoxyribonucleotides , Poly A/analysis , Poly A/genetics , RNA, Messenger/analysis , RNA, Messenger/genetics , Sequence Homology, Nucleic Acid , TCF Transcription Factors , Transcription Factor 4 , Transcription Factor 7-Like 2 Protein , Transfection
15.
J Virol ; 65(1): 42-50, 1991 Jan.
Article in English | MEDLINE | ID: mdl-1985206

ABSTRACT

Interactions between SL3-3 enhancer factor 1 (SEF1) proteins and the enhancer of the murine leukemia virus SL3-3 were analyzed. SEF1 proteins were found to interact with two different DNA sequences within the DNA repeat region of the enhancer; these two motifs cooperated in enhancing initiation of transcription in T lymphocytes. Using an electrophoretic mobility shift assay, we identified nucleotides that are important for the SEF1 binding, and we deduced a sequence, 5'-TTTGCGGTTA/T-3' with highly improved binding of SEF1 proteins. We show that many different SEF1 binding sequences exist in the transcription control regions of different viral and cellular genes. The results indicate a general role of SEF1 proteins in T-cell gene expression.


Subject(s)
Chromosomes/metabolism , DNA-Binding Proteins/metabolism , Enhancer Elements, Genetic , Genes, Viral , Trans-Activators/metabolism , Animals , Base Sequence , Binding Sites , Cell Line , HeLa Cells/metabolism , Humans , Molecular Sequence Data , Mutagenesis, Site-Directed , Oligonucleotide Probes , Protein Binding , Repetitive Sequences, Nucleic Acid , Retroviridae/genetics , Sequence Homology, Nucleic Acid , Software , Transcription, Genetic
16.
Nucleic Acids Res ; 17(11): 4061-75, 1989 Jun 12.
Article in English | MEDLINE | ID: mdl-2544855

ABSTRACT

Nuclear factor I (NFI) is shown to be of importance for the activity of the enhancer element of a T-cell leukemogenic murine retrovirus, SL3-3, and for the regulation of this element by glucocorticoid. Each nucleotide of the binding site of the NFI proteins was mutated, and the effects of the mutations were quantitated with an electrophoretic mobility shift assay. Mutations in the inverted repeat of the binding site have symmetric effects which strongly support the notion that NFI proteins preferentially bind to dyad symmetry sites. Such binding sites were shown to be more than 100 fold stronger than the corresponding single binding sites. We find dyad symmetry sequences which are much stronger NFI binding sites than NFI sites identified in different genes and also stronger than previously proposed consensus binding sequences for NFI.


Subject(s)
Base Sequence , CCAAT-Enhancer-Binding Proteins , DNA Mutational Analysis , DNA-Binding Proteins/genetics , Enhancer Elements, Genetic , Leukemia Virus, Murine/genetics , Transcription Factors , Animals , Base Composition , Binding, Competitive , Cell Line , Chromosome Deletion , DNA-Binding Proteins/metabolism , Gene Expression Regulation , Histones/metabolism , Mice , Molecular Sequence Data , NFI Transcription Factors , Nuclear Proteins , Rabbits , Y-Box-Binding Protein 1
17.
Mol Cell Biol ; 8(4): 1625-37, 1988 Apr.
Article in English | MEDLINE | ID: mdl-2837650

ABSTRACT

An electrophoretic mobility shift assay was used to characterize interactions of nuclear proteins with a DNA segment in the enhancer element of the leukemogenic murine retrovirus SL3-3. Mutation of a DNA sequence of the 5'-TGTGG-3' type decreased transcription in vivo specifically in T-lymphocyte cell lines. Extracts of nuclei from different T-lymphocyte cell lines or cells from lymphoid organs resulted in much higher amounts of complexes in vitro with this DNA sequence than did extracts from other cell lines or organs tested. Differences were also found in the sets of complexes obtained with extracts from the different types of cells. The DNA sequence specificities of the different SL3-3 enhancer factor 1 (SEF1) protein complexes were found to be distinct from those of several other previously identified DNA motifs of the TGTGG type because of differences in several nucleotides critical for binding and because these other DNA motifs could not compete with the identified DNA sequence for binding of SEF1. Limited treatment with several different proteases cleaved the SEF1 proteins such that their DNA-binding domain(s) remained and created complexes with decreased and nondistinguishable electrophoretic mobility shifts and with new properties. These results indicate that the SEF1 proteins have a structure with a flexible and relatively vulnerable hinge region linking a DNA-binding domain(s) to a more variable domain(s) with other functions. We suggest that the binding of SEF1 is an essential factor for the T-cell tropism of SL3-3 and the ability of this virus to cause T-cell lymphomas.


Subject(s)
Enhancer Elements, Genetic , Genes, Viral , Leukemia Virus, Murine/genetics , Lymphocytes/metabolism , Nuclear Proteins/metabolism , Animals , Base Sequence , Cell Line , Humans , Methylation , Mutation , Plasmids , Transcription, Genetic
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