a Representative images of micro-CT reconstruction of femora from LD12:12 and jet-lagged mice injected AMPK activator (ZLN024 hydrochloride, MCE, 15 mg/kg/d, injected before the dark onset for 21 days, jet-lagged mice were pretreated with jet lag for 2 weeks before the ZLN024 injection experiment) or equal solvent (1% DMSO + 99% Normal saline). b Micro-CT analysis of the total femora length, BV/TV, BS/TV, Tb.N, Tb.Sp, and Tb.Th of LD12:12 and jet-lagged mice injected ZLN024 or equal solvent (n = 3–5 per group). #P < 0.05, ##P < 0.01, ###P < 0.001, ZLN024 compared with solvent in jet-lagged mice. *P < 0.05, **P < 0.01, ***P < 0.001, LD12:12 compared with the Jet lag. c, d EdU staining of proliferating cells in PZ from the growth plate cartilages in LD12:12 and jet-lagged mice injected AMPK activator ZLN024 hydrochloride or equal solvent. Arrowheads indicate EdU+ cells (n = 3 for each bar). Scale bar, 50 μm. e Immunofluorescence of BMAL1, COL2α1, and ACAN in the growth plate cartilages from LD12:12 and jet-lagged mice injected AMPK activator ZLN024 hydrochloride or equal solvent (n = 3 per group), Scale bar, 50 μm. f, g Western blot analysis of the levels of AMPKβ1, p-AMPKβ1, AMPKα1/α2, p-AMPKα1/α2, BMAL1, CyclinD2, ACAN, COL2α1, and COL10α1 in the femoral metaphysis tissue from LD12:12 and jet-lagged mice treated with equal solvent or ZLN024 (n = 3 per group). h qRT-PCR analysis of the circadian rhythms of Bmal1, Ccnb3, Ccnd2, Col2α1, and Col10α1 in LD12:12 and jet-lagged mice treated with equal solvent or ZLN024 or melatonin supplementation at the indicated time (n = 3 per group). b, g Data were analyzed using one-way ANOVA with Tukey multiple comparisons test.