title: Partial hexokinase II knockout results in acute ischemia-reperfusion damage in skeletal muscle of male, but not female, mice.
abstract: Cellular studies have demonstrated a protective role of mitochondrial hexokinase against oxidative insults. It is unknown whether HK protective effects translate to the in vivo condition. In the present study, we hypothesize that HK affects acute ischemia-reperfusion injury in skeletal muscle of the intact animal. Male and female heterozygote knockout HKII (HK(+/-)), heterozygote overexpressed HKII (HK(tg)), and their wild-type (WT) C57Bl/6 littermates mice were examined. In anesthetized animals, the left gastrocnemius medialis (GM) muscle was connected to a force transducer and continuously stimulated (1-Hz twitches) during 60 min ischemia and 90 min reperfusion. Cell survival (%LDH) was defined by the amount of cytosolic lactate dehydrogenase (LDH) activity still present in the reperfused GM relative to the contralateral (non-ischemic) GM. Mitochondrial HK activity was 72.6 +/- 7.5, 15.7 +/- 1.7, and 8.8 +/- 0.9 mU/mg protein in male mice, and 72.7 +/- 3.7, 11.2 +/- 1.4, and 5.9 +/- 1.1 mU/mg in female mice for HK(tg), WT, and HK(+/-), respectively. Tetanic force recovery amounted to 33 +/- 7% for male and 17 +/- 4% for female mice and was similar for HK(tg), WT, and HK(+/-). However, cell survival was decreased (p = 0.014) in male HK(+/-) (82 +/- 4%LDH) as compared with WT (98 +/- 5%LDH) and HK(tg) (97 +/- 4%LDH). No effects of HKII on cell survival was observed in female mice (92 +/- 2% LDH). In conclusion, in this mild model of acute in vivo ischemia-reperfusion injury, a partial knockout of HKII was associated with increased cell death in male mice. The data suggest for the first time that HKII mediates skeletal muscle ischemia-reperfusion injury in the intact male animal.
authors.affiliation: Laboratory of Experimental Intensive Care and Anesthesiology, Department of Anaesthesiology, Academic Medical Center, Meibergdreef 9, 1105 Amsterdam, The Netherlands.
authors.forename: Kirsten M
authors.initials: KM
authors.lastname: Smeele
authors.forename: Otto
authors.initials: O
authors.lastname: Eerbeek
authors.forename: Anneke
authors.initials: A
authors.lastname: Koeman
authors.forename: Rick
authors.initials: R
authors.lastname: Bezemer
authors.forename: Can
authors.initials: C
authors.lastname: Ince
authors.forename: Sami
authors.initials: S
authors.lastname: Heikkinen
authors.forename: Markku
authors.initials: M
authors.lastname: Laakso
authors.forename: Arnold
authors.initials: A
authors.lastname: de Haan
authors.forename: Gert
authors.initials: G
authors.lastname: Schaart
authors.forename: Maarten R
authors.initials: MR
authors.lastname: Drost
authors.forename: Markus W
authors.initials: MW
authors.lastname: Hollmann
authors.forename: Coert J
authors.initials: CJ
authors.lastname: Zuurbier
mesh_terms: D000818:Animals; D005260:Female; D006593:Hexokinase / Q000235:genetics* / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D015427:Reperfusion Injury / Q000235:genetics* / Q000378:metabolism*; D012727:Sex Characteristics
chemical_list: D006593:Hexokinase