{'fraction_non_alphanumeric': 0.024268823895457373, 'fraction_numerical': 0.023024268823895456, 'mean_word_length': 5.617283950617284, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Spatiotemporal expression of heme oxygenase‐1 detected by in vivo bioluminescence after hepatic ischemia in HO‐1/luc mice

Upregulation of heme oxygenase‐1 (HO‐1) has been proposed as a critical mechanism protecting against cellular stress during liver transplantation, providing a potential target for new therapeutic interventions. We investigated the feasibility of in vivo bioluminescence imaging (BLI) to noninvasively quantify the spatiotemporal expression of HO‐1 after warm hepatic ischemia in living animals. Luciferase activity was measured by BLI as an index of HO‐1 transcription in transgenic reporter mice (Ho1‐luc) at standardized time points after 60 minutes of warm hepatic ischemia. HO‐1 mRNA levels were measured in postischemic livers of mice sacrificed at the same time points in separate experiments. Bioluminescent signals from postischemic liver lobes were first detected at 3 hours after reperfusion. Peak levels were reached at 9 hours, after which bioluminescent activity declined and returned to baseline values at 48 hours after reperfusion. Upregulation of HO‐1 as detected by in vivo BLI was preceded by increased HO‐1 mRNA expression and confirmed by enhanced immunohistochemical staining of hepatocytes. In conclusion, this study shows that in vivo BLI allows a sensitive assessment of HO‐1 expression after hepatic ischemia in living animals. The capability of whole‐body temporal imaging of HO‐1 expression provides a valuable tool in the development of novel strategies to modulate HO‐1 expression in liver transplantation. Liver Transpl 12:1634–1639, 2006. © 2006 AASLD.