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. 2014 Oct 14;111(41):14906-11.
doi: 10.1073/pnas.1415825111. Epub 2014 Sep 30.

Modulation of age-related insulin sensitivity by VEGF-dependent vascular plasticity in adipose tissues

Jennifer Honek  1 , Takahiro Seki  1 , Hideki Iwamoto  1 , Carina Fischer  1 , Jingrong Li  2 , Sharon Lim  1 , Nilesh J Samani  3 , Jingwu Zang  2 , Yihai Cao  4
Affiliations

Modulation of age-related insulin sensitivity by VEGF-dependent vascular plasticity in adipose tissues

Jennifer Honek et al. Proc Natl Acad Sci U S A. .

Abstract

Mechanisms underlying age-related obesity and insulin resistance are generally unknown. Here, we report age-related adipose vascular changes markedly modulated fat mass, adipocyte functions, blood lipid composition, and insulin sensitivity. Notably, VEGF expression levels in various white adipose tissues (WATs) underwent changes uninterruptedly in different age populations. Anti-VEGF and anti- VEGF receptor 2 treatment in different age populations showed marked variations of vascular regression, with midaged mice exhibiting modest sensitivity. Interestingly, anti-VEGF treatment produced opposing effects on WAT adipocyte sizes in different age populations and affected vascular density and adipocyte sizes in brown adipose tissue. Consistent with changes of vasculatures and adipocyte sizes, anti-VEGF treatment increased insulin sensitivity in young and old mice but had no effects in the midaged group. Surprisingly, anti-VEGF treatment significantly improved insulin sensitivity in midaged obese mice fed a high-fat diet. Our findings demonstrate that adipose vasculatures show differential responses to anti-VEGF treatment in various age populations and have therapeutic implications for treatment of obesity and diabetes with anti-VEGF-based antiangiogenic drugs.

Keywords: aging; angiogenesis; endothelial cells; metabolic disorders; vascularization.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.
Fig. 1.
Age-related changes of adipose vasculature and scWAT adipocyte size. (A) Body weight and BMI of 1-, 4-, 10-, 12-, and 16-mo-old mice (n = 10–12). (B) Histology of adipocytes and vascular density of scWAT. scWATs were stained with H&E, CD31 (red), or perilipin (PLPN, green) plus isolectin B4 (I-B4, red) counterstained with DAPI (blue) nucleus staining. Arrowheads point to microvessels. Dashed lines show diameters of typical adipocytes. (Scale bars, 50 μm.) (C) Average diameters of adipocytes of scWAT. Adipocyte sizes were quantified from 120 adipocytes from 12 fields. (D) Quantification of total microvessel density in scWAT (12 fields per group). (E) Quantification of microvessel numbers per adipocyte in scWAT (total numbers of microvessels were divided by total numbers of adipocytes per field; 12 fields per group). *P < 0.05, ***P < 0.001.
Fig. 2.
Fig. 2.
Age-related changes of adipose vasculature and intBAT adipocyte size. (A) Histology of intBAT adipocytes and vascular density. intBAT was stained with H&E, CD31 (red), or PLPN (green) plus I-B4 (red) with DAPI nucleus staining (blue). UCP1 (red), PLPN (green) and DAPI (blue) triple staining is shown in lowest panels. Arrowheads point to microvessels and arrows point to lipid droplets. (Scale bars, 50 μm.) (B) Total weight of intBAT of 1-, 4-, 10-, 12-, and 16-mo-old mice (n = 10–12). (C) Average diameters of intBAT adipocytes. Adipocyte sizes were quantified from 120 adipocytes from 12 fields. (D) Quantification of total vascular density and microvessel numbers per adipocyte in intBAT (12 fields per group). (E) Quantification of Ucp1 mRNA expression by qPCR (six samples in duplicates per group). (F) Quantification of VEGF protein levels in scWAT and epiWAT of different age groups (four samples in duplicates per group). (G) Colocalization of VEGFR1 protein expression with a specific anti-VEGFR1 antibody with I-B4 in scWAT, epiWAT, and intBAT. Arrows indicate VEGFR1 and I-B4 double-positive signals. Arrowheads point to nonoverlapping signals. (Scale bar, 50 μm.) (H) Colocalization of VEGFR2 protein expression with a specific anti-VEGFR2 antibody with endomucin (ENDO) in scWAT, epiWAT, and intBAT of 1-mo-old mice. Arrows indicate VEGFR2 and ENDO double-positive signals. Arrowheads point to nonoverlapping signals. (Scale bar, 50μm.) *P < 0.05, **P < 0.01, ***P < 0.001.
Fig. 3.
Fig. 3.
Anti-VEGF therapy-induced vascular and adipocyte changes in scWAT. (A) Histology of adipocytes and vascular density of anti-VEGF-- and vehicle-treated scWAT. scWATs were stained with H&E, CD31, or PLPN (blue) plus I-B4 (red) counterstained with DAPI (blue). Arrowheads point to microvessels. Dashed lines show diameters of typical adipocytes. (Scale bars, 50 μm.) (B) Body weight and BMI of anti-VEGF-- and vehicle-treated 1-, 7-, and 15-mo-old mice (10–18 mice per group). (C) Total weight of scWAT of anti-VEGF-- and vehicle-treated 1-, 7-, and 15-mo-old mice (n = 10–18). (D) Average diameters of anti-VEGF-- and vehicle-treated scWAT adipocytes. Adipocyte sizes were quantified from 120 adipocytes from 12 fields. (E) Quantification of total microvessel density and numbers per adipocyte in anti-VEGF-- and vehicle-treated scWAT (12 fields per group). *P < 0.05, **P < 0.01, ***P < 0.001.
Fig. 4.
Fig. 4.
Anti-VEGFR2 therapy-induced vascular and adipocyte changes in scWAT. (A) Histology of adipocytes and vascular density of anti-VEGFR2 (anti-R2)-- and vehicle-treated scWAT of different age groups. scWATs were stained with H&E, CD31, or PLPN plus I-B4 (red) counterstained with DAPI (blue). Arrowheads point to microvessels. Dashed lines show diameters of typical adipocytes. (Scale bars, 50 μm.) (B) Body weight and BMI of anti-R2-- and vehicle-treated 1-, 7-, and 15-mo-old C57BL/6 mice (n = 10). (C) Total weight of scWAT of anti-R2-- and vehicle-treated 1-, 7-, and 15-mo-old mice (n = 10). (D) Average diameters of anti-R2-- and vehicle-treated scWAT adipocytes. Adipocyte sizes were quantified from 120 adipocytes from 12 fields. (E) Quantification of total microvessel density and numbers per adipocyte in anti-R2-- and vehicle-treated scWAT (12 fields per group). *P < 0.05, **P < 0.01, ***P < 0.001.
Fig. 5.
Fig. 5.
Anti-VEGF-induced changes of blood lipids, glucose and insulin. (A) Serum levels of triglyceride, nonesterified fatty acids (NEFAs), glycerol, and cholesterol in anti-VEGF- and vehicle-treated 1-, 7-, and 15-mo-old mice (10–18 samples in duplicates per group). (B) Fasting serum levels of insulin and glucose of anti-VEGF- and vehicle-treated 1-, 7-, and 15-mo-old mice (10–18 samples in duplicates per group). (C) Homeostatic model assessment of insulin resistance (HOMA-IR) was calculated using the following formula: serum glucose × serum insulin/22.5. HOMA-IR was calculated based on values presented in B (10–18 samples in duplicates per group). (D) Insulin tolerance test in vehicle- and anti-VEGF-treated 1-mo-old mice (n = 10). Left panel shows basal serum levels of fasting glucose before insulin injection. These basal values were used to normalize the values measured at various time points presented in the right panel. (E) Insulin tolerance test in vehicle- and anti-VEGF-treated 7-mo-old mice (n = 12). (Left) Basal serum levels of fasting glucose before insulin injection. (Right) These basal values were used to normalize the values measured at various time points. (F) Insulin tolerance test in vehicle- and anti-VEGF-treated 15-mo-old mice (n = 15). (Left) Basal serum levels of fasting glucose before insulin injection. (Right) These basal values were used to normalize the values measured at various time points. (G) Body weight and BMI of anti-VEGF- and vehicle-treated HFD-fed mice (n = 10). (H) Weight of scWAT and epiWAT of vehicle- and anti-VEGF-treated HFD-fed mice (n = 10). (I) Fasting serum levels of insulin and glucose of anti-VEGF- and vehicle-treated HFD-fed mice (10 samples in duplicates per group). (J) HOMA-IR was calculated based on values presented in B (10 samples in duplicates per group). (K) Insulin tolerance test of vehicle- and anti-VEGF-treated HFD-fed mice. *P < 0.05, **P < 0.01, ***P < 0.001.
Fig. 6.
Fig. 6.
VEGF levels and anti-VEGF therapy-induced vascular and adipocyte changes in healthy and obese WATs. (A) Quantification of VEGF protein levels in scWAT and epiWAT of HFD-fed mice (four samples in duplicates per group). (B) Histology adipocytes and vascular density of anti-VEGF- and vehicle-treated scWAT and epiWAT of HFD-fed mice. WATs were stained with H&E, CD31, or PLPN (green) plus I- B4 (red) counterstained with DAPI (blue) nucleus staining. Arrowheads point to microvessels. Dashed lines show diameters of typical adipocytes. (Scale bars, 50 μm.) (C) Average diameters of anti-VEGF- and vehicle-treated scWAT and epiWAT adipocytes of HFD-fed mice. Adipocyte sizes were quantified from 120 adipocytes from 12 fields. (D) Quantification of total microvessel density in anti-VEGF- and vehicle-treated scWAT and epiWAT (12 fields per group). (E) Quantification of microvessel numbers per adipocyte in anti-VEGF- and vehicle-treated scWAT and epiWAT. ***P < 0.001.
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References

    1. Facchini FS, Hua N, Abbasi F, Reaven GM. Insulin resistance as a predictor of age-related diseases. J Clin Endocrinol Metab. 2001;86(8):3574–3578. - PubMed
    1. Johnson AM, Olefsky JM. The origins and drivers of insulin resistance. Cell. 2013;152(4):673–684. - PubMed
    1. Powell K. Obesity: The two faces of fat. Nature. 2007;447(7144):525–527. - PubMed
    1. Després JP, Lemieux I. Abdominal obesity and metabolic syndrome. Nature. 2006;444(7121):881–887. - PubMed
    1. Cao Y. Adipose tissue angiogenesis as a therapeutic target for obesity and metabolic diseases. Nat Rev Drug Discov. 2010;9(2):107–115. - PubMed

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