Figure 2. miR-33 and miR-33* reduce fatty acid oxidation and promote lipid body formation in M. tuberculosis-infected macrophages.

(a) Oxygen consumption rate (OCR) of BMDMs cultured with γ-Mtb for 6h and sequentially treated with Oligo, FCCP and rotenone plus antimycin (Rtn/AA) at the indicated times (arrows), measured in real time and presented as change in pMoles per unit time. (b) Maximal OCR of WT or miR-33^−/− BMDMs cultured with γ-Mtb for 6h measured in real time and presented as change in pMoles per unit time (OCR). (c) Immunofluorescence imaging of BODIPY-stained lipid droplets in control anti-miR, anti-miR-33 or anti-miR-33* treated THP-1 macrophages infected with H37Rv for 24h. Scale bar = 25μm. (d) Immunofluorescence (IF) imaging of WT or miR-33^−/− macrophages incubated with BODIPY-FL-C₁₆ and BSA-conjugated oleic acid for 48 h to label nascent lipid droplets and then infected with DsRed-H37Rv Mtb for 6h. Scale bar = 25μm. (e) IF imaging of BODIPY-stained lipid droplets in ctrl anti-miR, anti-miR33 or anti-miR33* treated macrophages, incubated with or without an inhibitor of lysosomal acid lipase (LALi, 10μM) for 8h. Scale bar = 10μm. NS, not significant, *P≤0.05, **P≤0.005 (Student’s t-test (b), one-way ANOVA (e)). Data are from one experiment representative of 3 (a, b; mean ± s.e.m, and d) or 2 (c and e; mean ± s.e.m) independent experiments with similar results.