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PNAS 109 (15): 5874-5879

Copyright © 2012 by the National Academy of Sciences.

Dichotomous effects of VEGF-A on adipose tissue dysfunction

Kai Suna, Ingrid Wernstedt Asterholma,1, Christine M. Kusminskia,1, Ana Carolina Buenoa,b, Zhao V. Wanga, Jeffrey W. Pollardc, Rolf A. Brekkend, and Philipp E. Scherera,e,2

aDepartment of Internal Medicine, Touchstone Diabetes Center, eDepartment of Cell Biology, and dHamon Center for Therapeutic Oncology and Division of Surgical Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390; bDepartment of Pediatrics, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil; and cDepartment of Developmental and Molecular Biology, Center of Reproductive Biology and Women's Health, Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461


Figure 01
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Fig. 1. VEGF-A stimulates angiogenesis in WAT. (A) Functional blood vessels in SWAT and BAT visualized by tail-injected rhodamine tagged lectin-1 in VEGF-A Tg and control mice. Blood vessels are shown in red and the nuclei are in blue, visualized by DAPI staining. The images were captured with confocal microscope. (B) q-PCR analysis of CD31 in SWAT of VEGF-A Tg and control mice (n = 4 in controls; n = 5 in VEGF-A Tg). The difference was analyzed by Student's t test. *P < 0.05. (C) Immunohistochemical analysis with α-CD31 in SWAT of VEGF Tg or their littermate controls. (Scale bar, 50 μm.) (D) Immunohistochemical analysis with α-VEGF receptor 2 and α-phosphorylated VEGF receptor 2 in SWAT in both VEGF Tg and controls. (Scale bar, 50 μm.)

 

Figure 02
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Fig. 2. VEGF-A Tg mice exhibit an improved metabolic profile. (A) Circulating glucose levels measured during an OGTT (n = 5 per group) 5 wk after HFD feeding. The difference at each time point was analyzed by Student's t test. *P < 0.05; **P < 0.001. (B) Indirect calorimetry was performed in a CLAMS system by housing mice after HFD plus Dox feeding for 6 wk. VO2 and RER (VCO2/VO2) were calculated from the average results during a 24-h light and dark cycle. Absolute contributions of carbohydrate and lipid metabolism to total energy expenditure and accumulated food intake were measured (ACC). *P < 0.05; **P < 0.001.

 

Figure 03
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Fig. 3. VEGF-A Tg mice have smaller white adipocytes with BAT-like properties. (A) H&E staining of SWAT of VEGF-A Tg mice after HFD plus Dox feeding for 8 wk. (Scale bars, 50 μm.) (B) q-PCR analysis of PGC-1α and UCP-1 in EWAT of VEGF-A Tg and their littermate controls. The readings are normalized to hypoxanthine phosphoribosyltransferase (HPRT). *P < 0.05; **P < 0.001. (C) Western blot analysis for both PGC-1α and UCP-1 in WAT of VEGF Tg and their littermate controls. Results were normalized with β-actin.

 

Figure 04
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Fig. 4. VEGF-A overexpression ameliorates hypoxia, fibrosis, and inflammatory responses in WAT induced by HFD. (A) Immunohistochemical staining by hypoprobe-1 in WAT of VEGF Tg mice and their littermate controls after HFD plus Dox treatment for 8 wk. The darker staining on the Left indicates more hypoxic environment in controls. (B) q-PCR analysis of HIF-1α and its target collagen genes in EWAT. The readings are normalized to HPRT. *P < 0.05; **P < 0.001. (C) q-PCR analysis of inflammatory cytokines IL6, TNFα, SAA3, and macrophage marker F4/80 in EWAT. The readings are normalized to HPRT. *P < 0.05; **P < 0.001. (D) Immunohistochemical staining of F4/80 in SWAT of VEGF-A Tg mice. Red arrows indicate the crowns formed by accumulation of macrophages surrounding the dysfunctional adipocytes.

 

Figure 05
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Fig. 5. Blockade of VEGF-A binding to VEGFR2 by Mcr84 accelerates metabolic dysfunction induced by HFD. (A) Functional blood vessels in AT labeled by rhodamine-tagged lectin. The mice were fed with HFD for 6 wk before the experiment. Mcr84 or control IgG were injected i.p at the initial stage and continued twice per week for the whole HFD feeding process. Blood vessels are shown in red and the nucleus in blue, by DAPI staining. (B) Insulin levels for an OGTT in Mcr84- or control IgG-treated mice (n = 5 per group) after antibody treated for 6 wk. *P < 0.05. (C) Triglyceride levels for a lipid clearance test in Mcr84- or control IgG-treated mice (n = 5 per group). *P < 0.05. (D) Serum nonesterified fatty acid (NEFA) levels in Mcr84- or control IgG-treated mice (n = 5 per group) after antibody treated for 7 wk. *P < 0.05.

 


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