1: Exp Gerontol. 2005 Sep 14; [Epub ahead of print] Human aging alters the first phase of the molecular response to stress in T-cells. Jurivich DA, Choo M, Welk J, Qiu L, Han K, Zhou X. Department of Medicine, Section of Geriatric Medicine (m/c 717), University of Illinois at Chicago & Jesse Brown VA Medical Center, 840 S. Wood St Chicago, IL 60612, USA. This study examines how age affects the first phase of the heat shock response in human T-cells. To understand how age alters transcriptional regulation of the heat shock genes, a cross-sectional study was conducted utilizing human T-cells enriched from peripheral blood lymphocytes of healthy young (20-40 years old) and old (>70 years old) donors. Nuclear run-on analysis revealed a 66% reduction in hsp70 transcription rates in old compared to young nuclei harvested from T-cells exposed to a brief 42 degrees C heat shock. To determine if one or more protein transactivators of the proximal and distal promoter regions of the hsp70 gene were affected by age, gel shift analysis was performed. Both HSF1 and SP1 DNA-binding were reduced with age but no reduction was noted in CCAAT-DNA binding. Western blot analysis indicated that HSF1 but not HSF2 protein levels were reduced in aged donor samples. These data suggest that human T-cell senescence involves a multi-factorial mechanism that diminishes an important transcriptional response to thermal stress. The results are discussed relative to recent studies that support a multi-factorial mechanism for age-dependent attenuation of the heat shock transcription factor. PMID: 16168601 [PubMed - as supplied by publisher] --------------------------------------------------------------- 2: Biol Reprod. 2004 Jun;70(6):1606-13. Epub 2004 Feb 6. Early transcriptional activation of the hsp70.1 gene by osmotic stress in one-cell embryos of the mouse. Fiorenza MT, Bevilacqua A, Canterini S, Torcia S, Pontecorvi M, Mangia F. Istituto Pasteur-Fondazione Cenci Bolognetti and Department of Psychology, Section of Neuroscience, UniversityLa Sapienza of Rome, 00185 Rome, Italy. In fertilized mouse eggs, de novo transcription of embryonic genes is first observed during the S phase of the one-cell stage. This transcription, however, is mostly limited to the male pronucleus and possibly uncoupled from translation, making the functional meaning obscure. We found that one-cell mouse embryos respond to the osmotic shock of in vitro isolation with migration of HSF1, the canonical stress activator of mammalian heat shock genes, to pronuclei and by transient transcription of the hsp70.1, but not hsp70.3 and hsp90, heat shock genes. Isolated growing dictyate oocytes also display a nuclear HSF1 localization, but, in contrast with embryos, they transcribe both hsp70.1 and hsp70.3 genes only after heat shock. Intranuclear injection of double-stranded oligodeoxyribonucleotides containing HSE, GAGA box or GC box consensus sequences, and antibodies raised to transcription factors HSF1, HSF2, Drosophila melanogaster GAGA factor, or Sp1 demonstrated that hsp70.1 transcription depends on HSF1 in both oocytes and embryos and that Sp1 is dispensable in oocytes and inhibitory in the embryos. Hsp70.1 thus represents the first endogenous gene so far identified to be physiologically activated and tightly regulated after fertilization in mammals. PMID: 14766729 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 3: Exp Cell Res. 2003 Aug 1;288(1):1-8. Regulation of the HIV1 long terminal repeat by mutant heat shock factor. Ignatenko NA, Gerner EW. Department of Radiation Oncology/Cancer Biology Section, Arizona Cancer Center, The University of Arizona, 1515 N. Campbell Avenue, Tucson, AZ 85724, USA. nignatenko@azcc.arizona.edu Heat shock is a known transcriptional activator of human immunodeficiency virus type 1 (HIV1) long terminal repeat (LTR). However, HIV1 LTR suppression can occur under hyperthermic conditions. To investigate this phenomenon, a series of HIV1 LTR deletion luciferase constructs were generated and tested in cell culture in combination with a mutant heat shock factor 1 (HSF1+), which is transcriptionally active in the absence of heat stress. HSF1+ suppressed the activity of a minimal HIV1 LTR promoter, which contained NF-kappaB, Sp1, and tat consensus sequences. Electromobility shift assays showed nuclear protein-DNA complex formation with a Sp1 consensus sequence. Immunoprecipitation of nuclear extracts with Sp1 antibody did not affect nuclear protein-Sp1 oligonucleotide complex formation. In contrast, no complexes were formed with the Sp1 consensus sequence when the HSF protein was immunoprecipitated. These experiments indicate that modified heat shock factor can suppress HIV1 promoter activity by a mechanism involving interaction with Sp1 elements in the HIV1 promoter. The ability of HSF1+ to suppress HIV1 promoter activity suggests that HSF1+ could serve as a tool for the treatment of AIDS. PMID: 12878154 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 4: Nucleic Acids Res. 1997 Apr 1;25(7):1333-8. Developmental activation of an episomic hsp70 gene promoter in two-cell mouse embryos by transcription factor Sp1. Bevilacqua A, Fiorenza MT, Mangia F. Department of Psychology and Department of Histology and Medical Embryology, La Sapienza University of Rome, Via Borelli 50, 00161 Rome, Italy. To investigate the control of zygotic genome expression in two-cell mouse embryos, we studied transcription factors required for transient expression of microinjected DNA constructs driven by the promoter of one of the earliest genes activated after fertilization in this system, the heat shock gene hsp70. Cis-acting elements required for hsp70 activation were first investigated by mutational analysis. Mutation of the TATA box and a proximal GC box strongly inhibited construct expression, while that of a CCAAT box had no effect. Transcription factors binding the wild-type hsp70 promoter were then titrated in vivo by coinjecting the construct with double-stranded oligodeoxyribonucleotides containing definite consensus sequences. Wild-type GC box oligonucleotides strongly inhibited construct expression, while those containing mutated GC boxes, wild-type CCAAT boxes, and heat shock elements had no effects. Finally, construct expression was challenged by coinjecting antibodies to specific transcription factors. Antibodies to factor Sp1 depressed construct expression in a dose-dependent manner, while those to Sp2, HSF1 and HSF2 were ineffective. These results pinpoint the Sp1 transcription factor as an absolute requirement for activation of the hsp70 gene promoter in two-cell mouse embryos, and make this factor a candidate for a major regulator of the onset of murine zygotic genome expression. PMID: 9060426 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 5: Exp Cell Res. 1995 Nov;221(1):103-10. Activation of multiple transcription factors and fos and jun gene family expression in cells exposed to a single electric pulse. Pazmany T, Murphy SP, Gollnick SO, Brooks SP, Tomasi TB. Department of Molecular Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263, USA. We report that exposure of cells to a single electric pulse (250-1250 V/cm) results in the rapid and persistent activation of the DNA binding activities of a number of transcription factors, including AP-1, SP1, AP-2, and NF-kappa B, and the transient expression of select members of the fos and jun gene families. Induction of gene expression occurs primarily at the level of transcription, although c-jun expression also appears to be regulated posttranscriptionally. Interestingly, maximal induction of gene expression is detected at electrical field strengths that do not result in pore formation in the plasma membrane and that do not significantly affect cell viability. Exposure of cells to electric pulses does not result in the activation of HSF1 DNA binding activity, or the induction of hsp70 or p53 protein synthesis, indicating that the induction of fos and jun gene expression is not coincident with protein or DNA damage. The results of these studies suggest that electrical pulses may represent a novel mechanism for inducing the activities of multiple transcription factors and the expression of select members of the fos and jun gene families. PMID: 7589234 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 6: Cell. 1995 Oct 6;83(1):29-38. Displacement of sequence-specific transcription factors from mitotic chromatin. Martinez-Balbas MA, Dey A, Rabindran SK, Ozato K, Wu C. Laboratory of Biochemistry, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA. The general inhibition in transcriptional activity during mitosis abolishes the stress-inducible expression of the human hsp70 gene. Among the four transcription factors that bind to the human hsp70 promoter, the DNA-binding activities of three (C/EBP, GBP, and HSF1) were normal, while Sp1 showed reduced binding activity in mitotic cell extracts. In vivo footprinting and immunocytochemical analyses revealed that all of the sequence-specific transcription factors were displaced from promoter sequences as well as from bulk chromatin during mitosis. The correlation of transcription factor displacement with chromatin condensation suggests an involvement of chromatin structure in mitotic repression. However, retention of DNase I hypersensitivity suggests that the hsp70 promoter was not organized in a canonical nucleosome structure in mitotic chromatin. Displacement of transcription factors from mitotic chromosomes could present another window in the cell cycle for resetting transcriptional programs. PMID: 7553870 [PubMed - indexed for MEDLINE] ---------------------------------------------------------------