Albumin cretg mice

Experiments were performed in accordance with the Institutional Animal Care and Use Committee guidelines with its approvals. The LKO mice were generated by crossing Albumin-CreTg/+ mice (Jackson Laboratories) with mice homozygous for a “floxed” exon 6 of IPMK (IPMK fl/fl). The control mice for this study were IPMK fl/fl (WT) mice. Mice were housed under standard conditions in a temperature- and humidity-controlled facility with a light–dark cycle of 12 h (lights on at 07:00) and fed ad libitum at the Johns Hopkins University (Baltimore, MD, USA).
Experiment 1: Eight-week-old WT mice were fed an ND (A02082003BY, Research Diets, New Brunswick, NJ, USA) or MCDD (A02082002BR, Research Diets, New Brunswick, NJ, USA) for 2 weeks.
Experiment 2: Eight-week-old WT and LKO mice were fed MCDD for 2 weeks.
Experiment 3: Ten-week-old WT mice were divided into two groups. One group (ALF) had ad libitum access to the MCDD diet, while the other group underwent time-restricted feeding (TRF), with access to the MCDD diet from 7 p.m. to 8 a.m., for two weeks.
All mice were sacrificed after a 5 h fast (from 08:00 a.m. to 1:00 p.m.), and blood was collected from the heart before harvesting liver tissues.

All mice are on a C57BL/6 background. The Sphk2-LKO mice were generated by cross-breeding Albumin-Cre^Tg/+ mice (Jackson Laboratories) with mice homozygous for a “floxed” exon 2 of Sphk2 (Sphk2^fl//fl) by Cyagen. All experiments involving Sphk2-LKO mice were approved by the Animal Use and Care Committees of Fudan University and Guangdong Pharmaceutical University, China, and confirmed with the US Public Health Service Policy on Humane Care and Use of Laboratory Animals. AlbCre progressively excises the floxed gene in mouse hepatocytes until a complete deletion at 6 wk of age (45 (link)). Thus, male floxed Sphk2 and Sphk2-LKO mice aged 6–8 wk were randomly assigned to be fed with either a CD or HFD (containing 60 kcal% fat, 20% protein, and 20% carbohydrate; Research Diets) for 20 wk. Mice were maintained in a 12-h light/dark cycle, allowed food and water ad libitum. Levels of plasma insulin (Insulin ELISA kit, Millipore), NEFA, TG, TC (WAKO kits), and ALT (ELISA Kit, TW-REAGENG) were measured after 16 h starvation. The use of global Sphk2^−/− mice, gifts from Richard Proia, The National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH) (14 (link)), was approved by Research Ethics and Governance Office, Royal Prince Alfred Hospital, Australia.