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Targeting curcusomes to inflammatory dendritic cells inhibits NF-κB and improves insulin resistance in obese mice.

Yekollu SK, Thomas R, O'Sullivan B - Diabetes (2011)

Bottom Line: Phagocytic myeloid cells infiltrating the liver in ob/ob mice had the phenotypic characteristics of Tip-DCs that arise from monocyte precursors in the liver and spleen after infection.Targeting Tip-DCs and ATMs with curcusomes in ob/ob mice reduced NF-κB/RelA DNA binding activity, reduced TNF, and enhanced interleukin-4 production.Targeting inflammatory DCs is a novel approach for type 2 diabetes treatment.

View Article: PubMed Central - PubMed

Affiliation: University of Queensland Diamantina Institute, Woolloongabba, Queensland, Australia.

ABSTRACT

Objective: To determine whether and by what mechanism systemic delivery of curcumin-containing liposomes improves insulin resistance in the leptin deficient (ob/ob) mouse model of insulin resistance.

Research design and methods: Insulin resistant ob/ob mice with steatosis were injected intraperitoneally with liposome nanoparticles, entrapping the nuclear factor-κB (NF-κB) inhibitor curcumin (curcusomes), and uptake in liver and adipose tissue was determined by flow cytometry. The effects of curcusomes on macrophage NF-κB activation and cytokine production were assessed. Transfer experiments determined the role of hepatic tumor necrosis factor (TNF)/inducible nitric oxide synthase-producing dendritic cells (Tip-DCs) and adipose tissue macrophages (ATMs) in inflammation-induced insulin resistance, determined by homeostatic assessment of insulin resistance.

Results: Phagocytic myeloid cells infiltrating the liver in ob/ob mice had the phenotypic characteristics of Tip-DCs that arise from monocyte precursors in the liver and spleen after infection. Targeting Tip-DCs and ATMs with curcusomes in ob/ob mice reduced NF-κB/RelA DNA binding activity, reduced TNF, and enhanced interleukin-4 production. Curcusomes improved peripheral insulin resistance.

Conclusions: Both hepatic Tip-DCs and ATMs contribute to insulin resistance in ob/ob mice. Curcusome nanoparticles inhibit proinflammatory pathways in hepatic Tip-DCs and ATMs and reverse insulin resistance. Targeting inflammatory DCs is a novel approach for type 2 diabetes treatment.

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In vivo delivery of curcusomes inhibits hepatic inflammatory DC cytokine production and nuclear RelA. A: Ob/ob and NOB mice were injected intraperitoneally (ip) with DiI-curcusomes, and gradient-purified liver cells were harvested at 24 and 72 h and stained for MHC class II, CD11c, and F4/80. Shown are the percentages of CD11c+ F4/80+ cells that are DiI+. Data are mean ± SEM of two separate experiments. B: Ob/ob mice were injected intraperitoneally with DiI-curcusomes for 72 h and then livers were harvested, frozen in optimal cutting temperature media, sectioned, and stained with F4/80 (green) and CD11c (blue) antibodies. DiI staining is indicated in red; images analyzed by immunofluorescence microscopy. Original magnification ×25. C: Nuclear extracts from CD11c+ liver cells isolated from ob/ob mice treated with or without curcusomes and cultured for 1 h with or without LPS were analyzed for DNA binding of RelA by chemiluminescent ELISA. Shown is the mean of duplicates from two separate experiments. D: mRNA from CD11c+ liver cells isolated from NOB mice and ob/ob mice treated with or without curcusomes for 72 h were analyzed by qPCR for relative expression of IL-4. E: mRNA from CD11c+ liver cells isolated from ob/ob mice treated with or without curcusomes for 24 and 72 h were analyzed by qPCR for relative expression of TNF, IL-6, and IL-1β. Shown is the fold increase in cytokine expression relative to the lowest expressing sample. Data are mean ± SEM of two separate experiments analyzing individual mice. *P ≤ 0.05, ***P ≤ 0.001 (one-way ANOVA followed by Bonferroni post hoc test). (A high-quality digital representation of this figure is available in the online issue.)
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Figure 3: In vivo delivery of curcusomes inhibits hepatic inflammatory DC cytokine production and nuclear RelA. A: Ob/ob and NOB mice were injected intraperitoneally (ip) with DiI-curcusomes, and gradient-purified liver cells were harvested at 24 and 72 h and stained for MHC class II, CD11c, and F4/80. Shown are the percentages of CD11c+ F4/80+ cells that are DiI+. Data are mean ± SEM of two separate experiments. B: Ob/ob mice were injected intraperitoneally with DiI-curcusomes for 72 h and then livers were harvested, frozen in optimal cutting temperature media, sectioned, and stained with F4/80 (green) and CD11c (blue) antibodies. DiI staining is indicated in red; images analyzed by immunofluorescence microscopy. Original magnification ×25. C: Nuclear extracts from CD11c+ liver cells isolated from ob/ob mice treated with or without curcusomes and cultured for 1 h with or without LPS were analyzed for DNA binding of RelA by chemiluminescent ELISA. Shown is the mean of duplicates from two separate experiments. D: mRNA from CD11c+ liver cells isolated from NOB mice and ob/ob mice treated with or without curcusomes for 72 h were analyzed by qPCR for relative expression of IL-4. E: mRNA from CD11c+ liver cells isolated from ob/ob mice treated with or without curcusomes for 24 and 72 h were analyzed by qPCR for relative expression of TNF, IL-6, and IL-1β. Shown is the fold increase in cytokine expression relative to the lowest expressing sample. Data are mean ± SEM of two separate experiments analyzing individual mice. *P ≤ 0.05, ***P ≤ 0.001 (one-way ANOVA followed by Bonferroni post hoc test). (A high-quality digital representation of this figure is available in the online issue.)

Mentions: To determine whether curcusomes also inhibited liver inflammatory Tip-DCs after intraperitoneal injection into ob/ob mice, we analyzed liver cells for uptake of DiI-curcusomes. Maximal curcusome uptake was observed at 72 h, where 30% of CD11c+F4/80+ cells were DiI+ (Fig. 3A). This was independent of liver steatosis, since NOB mice showed similar uptake of curcusomes. Immunofluorescent staining of liver sections from ob/ob mice injected with curcusomes 72 h earlier confirmed that Tip-DCs surrounding hepatocytes are the predominant cell type taking up liposomes (Fig. 3B).


Targeting curcusomes to inflammatory dendritic cells inhibits NF-κB and improves insulin resistance in obese mice.

Yekollu SK, Thomas R, O'Sullivan B - Diabetes (2011)

In vivo delivery of curcusomes inhibits hepatic inflammatory DC cytokine production and nuclear RelA. A: Ob/ob and NOB mice were injected intraperitoneally (ip) with DiI-curcusomes, and gradient-purified liver cells were harvested at 24 and 72 h and stained for MHC class II, CD11c, and F4/80. Shown are the percentages of CD11c+ F4/80+ cells that are DiI+. Data are mean ± SEM of two separate experiments. B: Ob/ob mice were injected intraperitoneally with DiI-curcusomes for 72 h and then livers were harvested, frozen in optimal cutting temperature media, sectioned, and stained with F4/80 (green) and CD11c (blue) antibodies. DiI staining is indicated in red; images analyzed by immunofluorescence microscopy. Original magnification ×25. C: Nuclear extracts from CD11c+ liver cells isolated from ob/ob mice treated with or without curcusomes and cultured for 1 h with or without LPS were analyzed for DNA binding of RelA by chemiluminescent ELISA. Shown is the mean of duplicates from two separate experiments. D: mRNA from CD11c+ liver cells isolated from NOB mice and ob/ob mice treated with or without curcusomes for 72 h were analyzed by qPCR for relative expression of IL-4. E: mRNA from CD11c+ liver cells isolated from ob/ob mice treated with or without curcusomes for 24 and 72 h were analyzed by qPCR for relative expression of TNF, IL-6, and IL-1β. Shown is the fold increase in cytokine expression relative to the lowest expressing sample. Data are mean ± SEM of two separate experiments analyzing individual mice. *P ≤ 0.05, ***P ≤ 0.001 (one-way ANOVA followed by Bonferroni post hoc test). (A high-quality digital representation of this figure is available in the online issue.)
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Related In: Results  -  Collection

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Figure 3: In vivo delivery of curcusomes inhibits hepatic inflammatory DC cytokine production and nuclear RelA. A: Ob/ob and NOB mice were injected intraperitoneally (ip) with DiI-curcusomes, and gradient-purified liver cells were harvested at 24 and 72 h and stained for MHC class II, CD11c, and F4/80. Shown are the percentages of CD11c+ F4/80+ cells that are DiI+. Data are mean ± SEM of two separate experiments. B: Ob/ob mice were injected intraperitoneally with DiI-curcusomes for 72 h and then livers were harvested, frozen in optimal cutting temperature media, sectioned, and stained with F4/80 (green) and CD11c (blue) antibodies. DiI staining is indicated in red; images analyzed by immunofluorescence microscopy. Original magnification ×25. C: Nuclear extracts from CD11c+ liver cells isolated from ob/ob mice treated with or without curcusomes and cultured for 1 h with or without LPS were analyzed for DNA binding of RelA by chemiluminescent ELISA. Shown is the mean of duplicates from two separate experiments. D: mRNA from CD11c+ liver cells isolated from NOB mice and ob/ob mice treated with or without curcusomes for 72 h were analyzed by qPCR for relative expression of IL-4. E: mRNA from CD11c+ liver cells isolated from ob/ob mice treated with or without curcusomes for 24 and 72 h were analyzed by qPCR for relative expression of TNF, IL-6, and IL-1β. Shown is the fold increase in cytokine expression relative to the lowest expressing sample. Data are mean ± SEM of two separate experiments analyzing individual mice. *P ≤ 0.05, ***P ≤ 0.001 (one-way ANOVA followed by Bonferroni post hoc test). (A high-quality digital representation of this figure is available in the online issue.)
Mentions: To determine whether curcusomes also inhibited liver inflammatory Tip-DCs after intraperitoneal injection into ob/ob mice, we analyzed liver cells for uptake of DiI-curcusomes. Maximal curcusome uptake was observed at 72 h, where 30% of CD11c+F4/80+ cells were DiI+ (Fig. 3A). This was independent of liver steatosis, since NOB mice showed similar uptake of curcusomes. Immunofluorescent staining of liver sections from ob/ob mice injected with curcusomes 72 h earlier confirmed that Tip-DCs surrounding hepatocytes are the predominant cell type taking up liposomes (Fig. 3B).

Bottom Line: Phagocytic myeloid cells infiltrating the liver in ob/ob mice had the phenotypic characteristics of Tip-DCs that arise from monocyte precursors in the liver and spleen after infection.Targeting Tip-DCs and ATMs with curcusomes in ob/ob mice reduced NF-κB/RelA DNA binding activity, reduced TNF, and enhanced interleukin-4 production.Targeting inflammatory DCs is a novel approach for type 2 diabetes treatment.

View Article: PubMed Central - PubMed

Affiliation: University of Queensland Diamantina Institute, Woolloongabba, Queensland, Australia.

ABSTRACT

Objective: To determine whether and by what mechanism systemic delivery of curcumin-containing liposomes improves insulin resistance in the leptin deficient (ob/ob) mouse model of insulin resistance.

Research design and methods: Insulin resistant ob/ob mice with steatosis were injected intraperitoneally with liposome nanoparticles, entrapping the nuclear factor-κB (NF-κB) inhibitor curcumin (curcusomes), and uptake in liver and adipose tissue was determined by flow cytometry. The effects of curcusomes on macrophage NF-κB activation and cytokine production were assessed. Transfer experiments determined the role of hepatic tumor necrosis factor (TNF)/inducible nitric oxide synthase-producing dendritic cells (Tip-DCs) and adipose tissue macrophages (ATMs) in inflammation-induced insulin resistance, determined by homeostatic assessment of insulin resistance.

Results: Phagocytic myeloid cells infiltrating the liver in ob/ob mice had the phenotypic characteristics of Tip-DCs that arise from monocyte precursors in the liver and spleen after infection. Targeting Tip-DCs and ATMs with curcusomes in ob/ob mice reduced NF-κB/RelA DNA binding activity, reduced TNF, and enhanced interleukin-4 production. Curcusomes improved peripheral insulin resistance.

Conclusions: Both hepatic Tip-DCs and ATMs contribute to insulin resistance in ob/ob mice. Curcusome nanoparticles inhibit proinflammatory pathways in hepatic Tip-DCs and ATMs and reverse insulin resistance. Targeting inflammatory DCs is a novel approach for type 2 diabetes treatment.

Show MeSH
Related in: MedlinePlus