Figure 1. Lkb1^BKO Mice Have Defective Adaptive Thermogenesis Regardless of Ucp1 Levels.

(A) Immunoblots showing amounts of Lkb1, pThr172-Ampk, total Ampk, Ucp1, and Hsp90 in BAT of ~8- to 10-week-old male control (CON) and Lkb1^BKO mice housed at room temperature (RT) and thermoneutrality (30°C).

(B) Quantitative analysis of western blot in (A).

(C) qPCR of Lkb1 and Ucp1 mRNA levels in BAT of ~8- to 10-week-old male CON and Lkb1^BKO mice housed at RT and 30°C. Sample size: CON/RT (n = 13), Lkb1^BKO/RT (n = 9), CON/30°C (n = 6), and Lkb1^BKO/30°C (n = 6).

(D and E) Recordings of energy expenditure (EE) increases in response to CL (D) and hourly average of CL-induced EE (E) in ~8- to 10-week-old male CON and Lkb1^BKO mice housed at RT and 30°C. CL injected at 0 hr.

(F) Regression plot of CL-induced EE as a function of mouse weight in ~8- to 10-week-old male CON and Lkb1^BKO mice housed at RT and 30°C. Sample size: CON/RT (n = 4), Lkb1^BKO/RT (n = 3), CON/30°C (n = 4), and Lkb1^BKO/30°C (n = 4).

(G) Seahorse experiments measuring oxygen consumption rates (OCR) of isolated mitochondria from BAT of ~8- to 10-week-old male CON and Lkb1^BKO mice housed at RT and 30°C, upon addition of ADP, Oligo, FCCP, and A&R.

(H and I) Average OCR (H) and RRC, proton leak, and ATP turnover rates (I) in seahorse measurements. Sample size: CON/RT (n = 4), Lkb1^BKO/RT (n = 6), CON/30°C (n = 9), and Lkb1^BKO/30°C (n = 9).

Oligo, oligomycin; FCCP, carbonyl cyanide-p-trifluromethoxyphenylhydrazone; A&R, antimycin and rotenone; RRC, reserve respiratory capacity. Data are means and error bars are ±SEM. Student’s t test, **p < 0.05 and ***p < 0.01.