title: A genetic reporter of thermal stress defines physiologic zones over a defined temperature range.
abstract: We define five unique cellular responses to thermal stress using a reporter construct generated using the stress-inducible promoter from the gene encoding a murine 70 kDa heat shock protein (Hsp70A.1) to express luciferase (luc). Thermal stress was delivered over a range of temperatures (42-68 degrees C) for 5 s to 20 min and luciferase activity was measured in live cells using a cooled CCD camera as a measure of reporter gene transcription. Reporter gene expression was assessed every 2 h for 10 h, and at 24 h post-stress. Expression patterns were validated for selected temperatures. A transition zone where cells lose the ability to produce light and beyond which >50% of cells die was observed to occur within a narrow (2.5 degrees C) temperature window. Although luc and hsp70 mRNA levels in this transition zone were high, there were reduced levels of Luc and Hsp70 protein and ATP levels. Cells treated at these temperatures recovered the ability to produce light in response to a secondary stress at 30 h. This Hsp70-luc reporter gene construct may be useful for defining zones of physiologic responses and assessing collateral thermal damage generated during treatment of biological tissue with lasers and other sources of heat.
authors.affiliation: Department of Pediatrics, Stanford School of Medicine, Stanford, California 94035-5208, USA.
authors.forename: Caitlin E
authors.initials: CE
authors.lastname: O'Connell-Rodwell
authors.forename: David
authors.initials: D
authors.lastname: Shriver
authors.forename: Dmitri M
authors.initials: DM
authors.lastname: Simanovskii
authors.forename: Cameron
authors.initials: C
authors.lastname: McClure
authors.forename: Yu-An
authors.initials: YA
authors.lastname: Cao
authors.forename: Weisheng
authors.initials: W
authors.lastname: Zhang
authors.forename: Michael H
authors.initials: MH
authors.lastname: Bachmann
authors.forename: Joshua T
authors.initials: JT
authors.lastname: Beckham
authors.forename: E Duco
authors.initials: ED
authors.lastname: Jansen
authors.forename: Daniel
authors.initials: D
authors.lastname: Palanker
authors.forename: H Alan
authors.initials: HA
authors.lastname: Schwettman
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Contag
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002470:Cell Survival; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000528:radiation effects*; D017930:Genes, Reporter / Q000235:genetics*; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D006358:Hot Temperature; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D041681:NIH 3T3 Cells; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D013997:Time Factors
chemical_list: D018840:HSP70 Heat-Shock Proteins; D012333:RNA, Messenger; D008156:Luciferases