Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have recently assigned a locus for familial psoriasis (PS) susceptibility to the region containing the epidermal differentiation complex gene cluster on chromosome 1q21. Gene S10OA7 maps within this cluster and is reported to be markedly over-expressed in the skin lesions of psoriatic patients. In order to analyse S100A7 as a candidate for PS susceptibility, we have determined its genomic structure regarding exon-intron boundaries and the transcription start site. The gene is organised in three exons and two introns, spanning 2.7 kb. The 5' flanking region contains AP1- and Sp1-binding motifs and a TATA box. We have performed functional assays by using the beta-galactosidase gene as a reporter and have confirmed that this region has strong promoter activity. To search for nucleotide variation within S100A7, we have designed a set of primers to amplify each exon and the gene promoter. Polymerase chain reaction products from 15 unrelated PS patients selected from 1q-linked pedigrees and 25 normal controls have been characterised by single-strand conformation polymorphism and direct sequencing techniques. These analyses have revealed the presence of two polymorphisms in the promoter region (-559G/A and -563 A/G), neither of which shows preferential association with the disease. Our results indicate that S100A7 can be excluded as a candidate for PS susceptibility.
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PMID:Genomic structure, promoter characterisation and mutational analysis of the S100A7 gene: exclusion of a candidate for familial psoriasis susceptibility. 1019 Mar 23

Tumour growth is dependent upon a blood supply and is associated with the switch to the angiogenic phenotype. We are developing strategies for targeting gene expression to endothelial cells in the tumour vasculature. Recombinant retroviruses have been generated that incorporate regulatory sequences of the prepro-endothelin-1 (ppET1) promoter. Following reverse transcription and integration these modifications are duplicated in the proviral 5' LTR for transcription of the internal beta-galactosidase reporter gene. The titres and endothelial specificity of retroviral vectors harbouring different modifications have been analysed. In the optimal strategy, replacing the MLV enhancer with ppET1 promoter sequences containing the GATA and AP1 elements whilst maintaining sequences from the viral promoter resulted in endothelial cell-specific expression of the reporter gene, and viral titres comparable to those of the unmodified vector. A panel of endothelial and non-endothelial cells infected with the modified virus from a high titre producer clone showed a pattern of expression consistent with the activity of the endogenous ppET1 promoter. The modified LTR retained specificity in vivo, in subcutaneous tumours arising from the co-injection of tumour cells and irradiated virus producer cells. This simple model achieves high efficiency of transduction and can be used routinely for the screening of targeted retroviral vectors. Gene Therapy (2000) 7, 368-376.
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PMID:Generation of a high titre retroviral vector for endothelial cell-specific gene expression in vivo. 1069 18

Analysis of complex signalisation networks involving distinct cell types is required to understand most developmental processes. Differentiation of male germ cells in adult mammals involves such a cross-talk between Sertoli cells, the somatic component which supports and controls germinal differentiation, and germ cells at their successive maturation stages. We developed a gene trapping strategy to identify genes, which, in Sertoli cells, are either up- or down-regulated by signals emitted by the germinal component. A library of approximately 2,000 clones was constituted from colonies independently selected from the Sertoli line 15P-1 by growth in drug-containing medium after random integration of a promoter-less (beta)geo transgene (neo(r)-lacZ fusion), which will be expressed as a fusion transcript from a 'trapped' cellular promoter, different in each clone. A first screen conducted on 700 events identified six clones in which beta-galactosidase activity was increased and one in which it was repressed upon addition of germ cells. The targeted loci were identified by cloning and sequencing the genomic region 5' of the insert. One of them was identified as the gene encoding Fra1, a component of the AP1 transcription regulatory complex. Accumulation of Fra1 mRNA was induced, both in 15P-1 and in freshly explanted Sertoli cells, by addition of either round spermatids or nerve growth factor (NGF). The effect of NGF was mediated by the TrkA receptor and the ERK1-ERK2 kinase kinase pathway. Fos and Fra1 transcription were induced within the first hour after addition of the neurotrophin, but, unlike what is observed after serum induction in the same cells, a second wave of transcription of Fra1, but not of Fos, started 16 hours later and peaked at higher levels at about 20 hours. These results suggest that AP1 activation may be an important relay in the Sertoli-germ cell cross-talk, and validate the gene trapping approach as a tool for the identification of target genes in cell culture systems.
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PMID:Gene trap analysis of germ cell signaling to Sertoli cells: NGF-TrkA mediated induction of Fra1 and Fos by post-meiotic germ cells. 3109 34

Altered transcriptional control is likely to contribute to the down-regulation of connexin 43 (Cx43) expression observed in many forms of heart disease. However, little is known about the factors regulating Cx43 transcription in the heart under (patho)physiological conditions. Therefore, a systematic study of rat Cx43 (rCx43) proximal promoter regulation in rat primary neonatal ventricular cardiomyocytes (NCM) and, for comparison, different cell types was initiated. Luciferase assays revealed that, in NCM, the proximal promoter is preserved in a conserved region extending from 148 nucleotides upstream towards 281 nucleotides downstream relative to the transcription initiation site (TIS). Further deletional analysis suggested the involvement of four putative Sp- and two AP1-binding sites. The binding of both Sp1 and Sp3 to the Sp-binding elements and AP1 to the AP1-binding elements was demonstrated by electrophoretic mobility shift assays (EMSA). Promoter-luciferase assays using the natural rCx43 proximal promoter and mutated derivatives in NCM, HL-1 and A7r5 cells revealed that all sites contribute to basal promoter activity. Trans-activation of the Cx43 proximal promoter with Sp1 and Sp3 in Drosophila Schneider line 2 (SL2) cells demonstrated that Sp1 and, to a lesser extent, Sp3 determine rCx43 promoter activation. Thus Sp1, Sp3 and AP1 determine basal Cx43 expression. In addition, we studied the effect of the cardiac transcription factor Nkx2.5 on Cx43 regulation. NCM were infected with adenovirus encoding either beta-galactosidase (control) or Nkx2.5. Cx43 protein and mRNA were significantly decreased after Nkx2.5 infection as shown by Western and Northern blot analyses. Promoter-reporter assays demonstrated that the rCx43 promoter was down-regulated approximately twofold upon Nkx2.5 overexpression. Therefore, in NCM, Nkx2.5 appears to play a role in the regulation of Cx43 expression.
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PMID:Analysis of the rat connexin 43 proximal promoter in neonatal cardiomyocytes. 1464 4

Endothelial cell (EC) senescence and dysfunction occurring after chronic injury and inflammation are highly associated with the development and progression of cardiovascular diseases. However, the factors involved in the establishment of EC senescence remain poorly understood. We have previously shown that lithium, an inhibitor of glycogen synthase kinase (GSK)-3beta and activator of the Wnt/beta-catenin signaling pathway, induces an EC senescent-like phenotype. Herein, we show that lithium induces a rapid and pronounced up-regulation of the matrix metalloproteinase (MMP)-1, an inflammation and senescent cell marker, at the mRNA and protein levels, whereas the induction of two other senescent cell markers is either weak (interleukin-8) or delayed (plasminogen activator inhibitor-1). Lithium effect on MMP-1 expression is also specific among other MMPs and not mediated by GSK3beta inhibition. Lithium affects MMP-1 expression mainly at the transcriptional level but neither the AP1/Ets regulatory sites nor the redox sensitive (-1607/2G) site in MMP-1 promoter are involved in lithium-dependent MMP-1 regulation. However, down-regulation of p53, a target of lithium in EC, dampens both basal and lithium-induced MMP-1 expression, which further links MMP-1 up-regulation with the establishment of cell senescence. Although increased MMP-1 levels are usually associated with angiogenesis in enabled proliferative EC, the exogenous addition of activated MMP-1 on lithium- arrested EC increases the number of EC positive for the senescent-associated-beta-galactosidase marker. Conversely, down-regulation of MMP-1 expression by small interfering RNAs blunts the lithium-dependent increase in senescent-associated-beta-galactosidase positive cells. Altogether our data indicate that lithium-induced MMP-1 may participate in the reinforcement of EC senescence and reveal a novel mechanism for lithium-induced tissue remodeling.
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PMID:Enhanced endothelial cell senescence by lithium-induced matrix metalloproteinase-1 expression. 1940 40

Colon cancer is the third and fourth most prevalent cancer among Iranian men and women, respectively. Suicide gene therapy is one of the alternative therapeutic modalities for cancer. The application of specific promoters for therapeutic genes should decrease the adverse effects of this modality. The combined aims of this study were to design a specific suicide gene therapy construct for colon cancer and study its effect in distinct representatives of transformed and nontransformed cells. The KRAS oncogene signaling pathway is one of the most important signaling pathways activated in colon cancer; therefore, we inserted the urokinase plasminogen activator receptor (uPAR; PLAUR gene) promoter as one of the upregulated promoters by this pathway upstream of a suicide gene (thymidine kinase [TK]) and a reporter gene (beta-galactosidase, beta-gal [LacZ]). This promoter is a natural combination of different motifs responsive to the RAS signaling pathway, such as the transcription factors AP1 (FOS/JUN), SP1, SP3, and AP2alpha, and nuclear factor kappa B (NFkappaB). The reporter plasmid under the control of the uPAR promoter (PUCUPARLacZ) had the ability to express beta-gal in colon cancer cells (human colon adenocarcinoma [SW480] and human colorectal carcinoma [HCT116] cell lines), while it could not express beta-gal in nontransformed human umbilical vein endothelial cells (HUVEC) and normal colon cells. After confirming the ability of pUCUPARTK (suicide plasmid) to express TK in SW480 and HCT116 cells by real-time PCR, cytotoxicity assays showed that pUCUPARTK decreased the viability of these cells in the presence of ganciclovir 20 and 40 microg/mL (and higher), respectively. Although M30 CytoDEATH antibody could not detect a significant rate of apoptosis induced by ganciclovir in pUCUPARTK-transfected HCT116 cells, the percentage of stained cells was marked in comparison with untreated cells. While this antibody could detect apoptosis in HCT116 cell line transfected with positive control plasmid, it could not detect apoptosis in SW480 cells transfected with the same positive control. This discrepancy could be attributed to the different mechanisms of TK/ganciclovir-induced apoptosis in tumor protein p53 (TP53)-expressing (HCT116) and -deficient (SW480) cells. Annexin-propidium iodide staining could detect apoptosis in treated, pUCUPARTK-transfected SW480 and HCT116 cells. This study showed that the uPAR promoter can be considered as a suitable candidate for specific suicide gene therapy of colon cancer and probably other cancers in which the RAS signaling pathway is involved in their carcinogenesis process.
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PMID:Selective suicide gene therapy of colon cancer exploiting the urokinase plasminogen activator receptor promoter. 2019 27