Central nicotine induces browning through hypothalamic κ opioid receptor

Figures

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  Fig. 1. Effect of central nicotine WAT browning. a Body weight change (vehicle n = 12, nicotine n = 16 mice). b Daily food intake (vehicle n = 12, nicotine n = 16 mice). c Fat depot mass (vehicle n = 10, nicotine n = 7 mice). d mRNA levels of thermogenic markers in the gWAT (vehicle n = 11, 11, 11, 12, nicotine n = 15, 16, 13, 15 mice). e UCP1 staining (left panel 40×, scale bar: 100 μm) and UCP1 stained area (right panel) in gWAT (vehicle n = 13, nicotine n = 14 mice). f H&E staining (left panel 40×, scale bar: 100 μm) and adipocyte area (right panel) in gWAT (vehicle n = 13, nicotine n = 15 mice). g UCP1 staining (left panel 40×, scale bar: 100 μm) and UCP1 stained area (right panel) in sWAT (vehicle n = 10, nicotine n = 6 mice). h H&E staining (left panel 40×, scale bar: 100 μm) and adipocyte area (right panel) in sWAT (vehicle n = 10, nicotine n = 6 mice). i UCP1 staining (left panel 40×, scale bar: 100 μm) and UCP1 stained area (right panel) in vWAT (vehicle n = 10, nicotine n = 7 mice). j H&E staining (left panel 40×, scale bar: 100 μm) and adipocyte area (right panel) in vWAT (vehicle n = 10, nicotine n = 7 mice) of mice ICV treated with vehicle or nicotine. Center values…

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  Fig. 2. Effect of central nicotine on SNS. a–b Sympathetic nerve activity (SNA) recorded from the nerves subserving sWAT (vehicle n = 6, nicotine n = 5 mice). c NE levels in gWAT, sWAT, and vWAT (vehicle n = 5, 6, 6, nicotine n = 7, 7, 7 mice). d TH immunohistochemistry (right panel, scale bar: 1000 μm) and quantification of SNS neurite length, area and volume (left panel) in gWAT (vehicle n = 4, nicotine n = 4 mice). White arrows represent dendrites of mice treated ICV with vehicle or nicotine. Center values represent average; error bars represent SEM. Statistical significance was determined by two-sided t-Student; *P < 0.05, **P < 0.01, ***P < 0.001 vs. vehicle. Source data are provided as a Source Data file

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  Fig. 3. Effect of nicotine on energy balance in KOR null mice. a–b Body weight change (WT vehicle n = 12, WT nicotine n = 14, KO vehicle n = 14, KO nicotine n = 13 mice). c–d Body composition (Fat mass WT vehicle n = 10, WT nicotine n = 13, KO vehicle n = 8, KO nicotine n = 8; Lean mass WT vehicle n = 10, WT nicotine n = 13, KO vehicle n = 5, KO nicotine n = 5 mice). e–f Fat pads mass (WT vehicle n = 11, 11, 9 11, WT nicotine n = 13, 13, 12, 13, KO vehicle n = 9, 9, 8, 9, KO nicotine n = 7, 7, 7, 7 mice). g–h Energy expenditure (EE) (WT vehicle n = 5, WT nicotine n = 6, KO vehicle n = 5, KO nicotine n = 5 mice) of WT (a, c, e, and g) or KOR KO (b, d, f, and h) mice treated with vehicle or nicotine. Center values represent average; error bars represent SEM. Statistical significance was determined by two-sided t-Student; *P < 0.05, **P < 0.01 vs. vehicle. The experiments were repeated two times; the samples represent biological replicates. Source data are provided as a Source Data file

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  Fig. 4. Effect of nicotine on BAT and WAT in KOR null mice. a–c Representative images (left panels) and protein levels of UCP1 in the BAT (right panels) (WT vehicle n = 11, WT nicotine n = 12, KO vehicle n = 8, KO nicotine n = 8 mice). b–d mRNA levels of thermogenic markers in the BAT (WT vehicle n = 8, 8, 8, 8, 8, 7, WT nicotine n = 8, KO vehicle n = 8, KO nicotine n = 8, 8, 8, 7, 8, 7 mice). e–f UCP1 staining (left panels 40×, scale bar: 100 μm) and UCP1 stained area (right panels) in gWAT (WT vehicle n = 10, WT nicotine n = 12, KO vehicle n = 14, KO nicotine n = 11 mice). g–h H&E staining (left panels 40×, scale bar: 100 μm) and adipocyte area (right panels) in gWAT (WT vehicle n = 10, WT nicotine n = 13, KO vehicle n = 14, KO nicotine n = 11 mice). i–j mRNA levels of thermogenic markers in the gWAT (WT vehicle n = 7, 8, 7, 7, WT nicotine n = 7, 7, 6, 8, KO vehicle n = 6, 8, 7, 8, KO nicotine n = 8, 8, 8, 8 mice) of WT (a, b, e, g and i) or KOR KO (c, d, f, h and j) mice treated with vehicle or nicotine. Center values represent average; error bars represent SEM. Statistical significance was determined by two-sided t-Student; *P < 0.05, **P < 0.01, ***P < 0.001 vs. vehicle. The…

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  Fig. 5. Effect of LHA Opkr1 knockdown on nicotine’s effect on BAT and WAT. a–b Body weight (vehicle + shRNA-null LHA n = 8, nicotine + shRNA-null LHA n = 6, vehicle + shRNA-Opkr1 LHA n = 8, nicotine + shRNA-Opkr1 LHA n = 9 rats). c–e Representative images (left panels) and protein levels of UCP1 in the BAT (right panels) (vehicle + shRNA-null LHA n = 7, nicotine + shRNA-null LHA n = 6, vehicle + shRNA-Opkr1 LHA n = 7, nicotine + shRNA-Opkr1 LHA n = 7 rats). d–f mRNA levels of thermogenic markers in the BAT (vehicle + shRNA-null LHA n = 8, nicotine + shRNA-null LHA n = 6, vehicle + shRNA-Opkr1 LHA n = 7, 8, 8, 8, 8, 8, nicotine + shRNA-Opkr1 LHA n = 9, 9, 9, 9, 9, 7 rats). g–h UCP1 staining (left panels 20 × , scale bar: 100 μm) and UCP1 stained area (right panels) in gWAT (vehicle + shRNA-null LHA n = 8, nicotine + shRNA-null LHA n = 6, vehicle + shRNA-Opkr1 LHA n = 8, nicotine + shRNA-Opkr1 LHA n = 8 rats). i–j H&E staining (left panels 20×, scale bar: 100 μm) and adipocyte area (right panels) in gWAT (vehicle + shRNA-null LHA n = 8, nicotine + shRNA-null LHA n = 6, vehicle + shRNA-Opkr1 LHA n = 8, nicotine + shRNA-Opkr1 LHA, n = 9 rats). k–l mRNA levels of thermogenic markers in the…

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  Fig. 6. Effect of smoking status on WAT browning. a–c UCP1 mRNA levels in sWAT, BMI and age in non-smokers or current smokers from cohort 1 (Non smoker n = 20, Smoker n = 5). Statistical analysis was performed with one factor ANOVA with post-hoc Bonferroni test; the samples represent biological replicates. Center values (black lines) represent median. d Bivariate correlation between sWAT UCP1 mRNA levels and cigarettes per day on current smokers from cohort 1 (n = 25). This correlation was similar using parametric (Pearson, r = 0.46, P = 0.02) or non-parametric (Spearman, r = 0.45, P = 0.02) correlations. e Relationship between the BMI, age, and cotinine adjusted residuals of the multiple linear regression model and UCP1 gene expression in vWAT (n = 56). The samples represent biological replicates. Source data are provided as a Source Data file