Expression of hypoxia inducible factor-1α during liver regeneration induced by partial hepatectomy in rats

Authors


Hiroshi, Maeno, MD
Department of Digestive and General Surgery,
Faculty of Medicine, Shimane University,
Enya-chou, Izumo 693-8501,
Japan.
Tel: +81 853 20 2232
Fax: +81 853 20 2229
e-mail: hm7777@med.shimane-u.ac.jp

Abstract

Abstract: Background/Aims: It has been well established that hypoxia inducible factor-1α (HIF-1α) transcribes essential factors in cell preservation, including angiogenesis, during hypoxia. However, the transition of HIF-1α expression during liver regeneration remains unknown. In this study, a role of HIF-1α was experimentally elucidated in relation to sinusoidal endothelial reconstruction during liver regeneration.

Methods: Expression of HIF-1α was evaluated in the regenerating liver following 70% hepatectomy in rats. Expressions of nuclear HIF-1α, vascular endothelial growth factor (VEGF) and fms-like tyrosine kinase-1 (flt-1) were measured by Western blot and liver blood flow by a laser Doppler. Sinusoidal endothelial cell area (SECA) and HIF-1α were localized by immunohistochemistry. HIF-1α mRNA was measured by reverse transcription-polymerase chain reaction.

Result: Liver blood flow and SECA were lowest 36 and 72 h following hepatectomy, respectively. Nuclear HIF-1α peaked at 24 h and continuously increased 72–120 h following hepatectomy. This transition was fully supported by histological HIF-1α expression and HIF-1α mRNA up-regulation. VEGF and flt-1 peaked at 120 and 12 h, respectively.

Conclusions: A significant evaluation in HIF-1α expression was revealed in regenerating rat livers. HIF-1α expression was preceded by VEGF and flt-1 expression and thus may be related to sinusoidal endothelial reconstruction.

Ancillary