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VEGF-C is required for intestinal lymphatic vessel maintenance and lipid absorption.

Nurmi H, Saharinen P, Zarkada G, Zheng W, Robciuc MR, Alitalo K - EMBO Mol Med (2015)

Bottom Line: We show here that VEGF-C is necessary for perinatal lymphangiogenesis, but required for adult lymphatic vessel maintenance only in the intestine.VEGF-C was expressed by a subset of smooth muscle cells adjacent to the lacteals in the villus and in the intestinal wall.Our findings indicate that the lymphangiogenic growth factors provide trophic and dynamic regulation of the intestinal lymphatic vasculature, which could be especially important in the dietary regulation of adiposity and cholesterol metabolism.

View Article: PubMed Central - PubMed

Affiliation: Wihuri Research Institute and Translational Cancer Biology Program, Biomedicum Helsinki University of Helsinki, Helsinki, Finland.

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Intestinal lymphatic vessel regression leads to impaired lipid absorption and resistance to diet-induced obesityTwo-month-old mice received tamoxifen and were fed on high-fat diet (HFD) for seven weeks before analysis.Body weight change during seven weeks of HFD, expressed as average fold change in comparison with the starting weight. n = 16, WT; n = 6, Vegfd−/−; n = 16, VCiΔR26; n = 5, Vegfd−/−; VCiΔR26.Body weight comparisons at seven weeks of HFD. Significant differences were determined using one-way ANOVA and Bonferroni post hoc analysis compared to WT. *P = 0.004; **P = 0.003. n = 16, WT; n = 6, Vegfd−/−; n = 16, VCiΔR26; n = 5, Vegfd−/−; VCiΔR26.Glucose tolerance test (GTT) after six weeks of HFD. Significant differences were determined using unpaired two-tailed t-test. *P = 0.014; **P = 0.041. n = 5, WT; n = 6, VCiΔR26.Total fat weight, fat percentage from body composition measurements after six weeks of HFD, and weights of visceral fat (VF) and subcutaneous fat (SF) at the time of necropsy. Significant differences were determined using unpaired two-tailed t-test. *P = 0.006; **P = 0.001; #P = 0.008; §P = 0.006. n = 4 in each group.Food consumption during the fifth week of HFD. n = 9, WT; n = 10, VCiΔR26.Whole-mount immunofluorescence staining of blood (PECAM1, red) and lymphatic vessels (LYVE1, green) in intestinal villi and intestinal wall.Quantification of the lacteal and villus length (solid and striped color bars, respectively) and the intestinal wall LYVE1+ area percentage from images represented in (F). Significant differences were determined using unpaired two-tailed t-test. *P = 0.0002; **P = 0.00007. n = 5, WT; n = 6, VCiΔR26.Free fatty acid (FFA) and cholesterol measurements from the feces after six weeks of HFD. Significant differences were determined using unpaired two-tailed t-test. *P = 0.001; **P = 0.007. n = 5, WT; n = 6, VCiΔR26.Data information: Scale bars: 100 μm (villi) and 300 μm (intestinal wall). Data are represented as mean ± SEM.
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fig03: Intestinal lymphatic vessel regression leads to impaired lipid absorption and resistance to diet-induced obesityTwo-month-old mice received tamoxifen and were fed on high-fat diet (HFD) for seven weeks before analysis.Body weight change during seven weeks of HFD, expressed as average fold change in comparison with the starting weight. n = 16, WT; n = 6, Vegfd−/−; n = 16, VCiΔR26; n = 5, Vegfd−/−; VCiΔR26.Body weight comparisons at seven weeks of HFD. Significant differences were determined using one-way ANOVA and Bonferroni post hoc analysis compared to WT. *P = 0.004; **P = 0.003. n = 16, WT; n = 6, Vegfd−/−; n = 16, VCiΔR26; n = 5, Vegfd−/−; VCiΔR26.Glucose tolerance test (GTT) after six weeks of HFD. Significant differences were determined using unpaired two-tailed t-test. *P = 0.014; **P = 0.041. n = 5, WT; n = 6, VCiΔR26.Total fat weight, fat percentage from body composition measurements after six weeks of HFD, and weights of visceral fat (VF) and subcutaneous fat (SF) at the time of necropsy. Significant differences were determined using unpaired two-tailed t-test. *P = 0.006; **P = 0.001; #P = 0.008; §P = 0.006. n = 4 in each group.Food consumption during the fifth week of HFD. n = 9, WT; n = 10, VCiΔR26.Whole-mount immunofluorescence staining of blood (PECAM1, red) and lymphatic vessels (LYVE1, green) in intestinal villi and intestinal wall.Quantification of the lacteal and villus length (solid and striped color bars, respectively) and the intestinal wall LYVE1+ area percentage from images represented in (F). Significant differences were determined using unpaired two-tailed t-test. *P = 0.0002; **P = 0.00007. n = 5, WT; n = 6, VCiΔR26.Free fatty acid (FFA) and cholesterol measurements from the feces after six weeks of HFD. Significant differences were determined using unpaired two-tailed t-test. *P = 0.001; **P = 0.007. n = 5, WT; n = 6, VCiΔR26.Data information: Scale bars: 100 μm (villi) and 300 μm (intestinal wall). Data are represented as mean ± SEM.

Mentions: We further studied whether the reduction in dietary lipid absorption observed in the VCiΔR26 mice has an impact on diet-induced obesity in mice fed high-fat diet (HFD). Initial experiments in the 129SV/C57Bl/6J mixed genetic background did not reveal major differences in body weight, but indicated that the VCiΔR26 mice have an improved glucose metabolism compared to WT mice (Appendix Fig S5B and C). Interestingly, in the mixed background, the Vegfc-deleted mice had reduced serum cholesterol levels, whereas fecal cholesterol and free fatty acid (FFA) levels were increased in the VCiΔR26 mice, indicating impaired dietary lipid absorption (Appendix Fig S5D). We further performed HFD feeding experiments in the pure C57Bl/6J background, an established model of diet-induced obesity. We deleted Vegfc in 8-week-old male mice and started HFD feeding 4 weeks later. The VCiΔR26 mice gained significantly less weight and had better glucose tolerance than their WT littermates, independently of concurrent Vegfd deletion (Fig3A–C and Appendix Fig S5E and F). At necropsy after HFD, very low amounts of chyle were detected in one out of 16 Vegfc-deleted mice and in two out of five Vegfc- plus Vegfd-deleted mice, indicating mild lymphatic leakage. Body composition analysis showed that the VCiΔR26 mice had a significant reduction in total fat weight and fat percentage, but no changes in lean weight in comparison with WT littermates (Fig3D and Appendix Fig S5G). The changes in fat accumulation could not be explained by reduced caloric intake, since food consumption was similar between the VCiΔR26 and WT mice (Fig3E). As expected on the basis of our results from the mixed background, Vegfc deletion induced intestinal lymphatic vessel atrophy and increased lipid excretion into the feces also in the C57Bl/6J background (Fig3F–H). No difference in body weight was observed between WT and Vegfc-deleted mice on regular diet in which the majority of calories are derived from carbohydrate. This further indicates that the reduced body weight of the Vegfc-deleted mice on HFD is a result of reduced dietary lipid absorption.


VEGF-C is required for intestinal lymphatic vessel maintenance and lipid absorption.

Nurmi H, Saharinen P, Zarkada G, Zheng W, Robciuc MR, Alitalo K - EMBO Mol Med (2015)

Intestinal lymphatic vessel regression leads to impaired lipid absorption and resistance to diet-induced obesityTwo-month-old mice received tamoxifen and were fed on high-fat diet (HFD) for seven weeks before analysis.Body weight change during seven weeks of HFD, expressed as average fold change in comparison with the starting weight. n = 16, WT; n = 6, Vegfd−/−; n = 16, VCiΔR26; n = 5, Vegfd−/−; VCiΔR26.Body weight comparisons at seven weeks of HFD. Significant differences were determined using one-way ANOVA and Bonferroni post hoc analysis compared to WT. *P = 0.004; **P = 0.003. n = 16, WT; n = 6, Vegfd−/−; n = 16, VCiΔR26; n = 5, Vegfd−/−; VCiΔR26.Glucose tolerance test (GTT) after six weeks of HFD. Significant differences were determined using unpaired two-tailed t-test. *P = 0.014; **P = 0.041. n = 5, WT; n = 6, VCiΔR26.Total fat weight, fat percentage from body composition measurements after six weeks of HFD, and weights of visceral fat (VF) and subcutaneous fat (SF) at the time of necropsy. Significant differences were determined using unpaired two-tailed t-test. *P = 0.006; **P = 0.001; #P = 0.008; §P = 0.006. n = 4 in each group.Food consumption during the fifth week of HFD. n = 9, WT; n = 10, VCiΔR26.Whole-mount immunofluorescence staining of blood (PECAM1, red) and lymphatic vessels (LYVE1, green) in intestinal villi and intestinal wall.Quantification of the lacteal and villus length (solid and striped color bars, respectively) and the intestinal wall LYVE1+ area percentage from images represented in (F). Significant differences were determined using unpaired two-tailed t-test. *P = 0.0002; **P = 0.00007. n = 5, WT; n = 6, VCiΔR26.Free fatty acid (FFA) and cholesterol measurements from the feces after six weeks of HFD. Significant differences were determined using unpaired two-tailed t-test. *P = 0.001; **P = 0.007. n = 5, WT; n = 6, VCiΔR26.Data information: Scale bars: 100 μm (villi) and 300 μm (intestinal wall). Data are represented as mean ± SEM.
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fig03: Intestinal lymphatic vessel regression leads to impaired lipid absorption and resistance to diet-induced obesityTwo-month-old mice received tamoxifen and were fed on high-fat diet (HFD) for seven weeks before analysis.Body weight change during seven weeks of HFD, expressed as average fold change in comparison with the starting weight. n = 16, WT; n = 6, Vegfd−/−; n = 16, VCiΔR26; n = 5, Vegfd−/−; VCiΔR26.Body weight comparisons at seven weeks of HFD. Significant differences were determined using one-way ANOVA and Bonferroni post hoc analysis compared to WT. *P = 0.004; **P = 0.003. n = 16, WT; n = 6, Vegfd−/−; n = 16, VCiΔR26; n = 5, Vegfd−/−; VCiΔR26.Glucose tolerance test (GTT) after six weeks of HFD. Significant differences were determined using unpaired two-tailed t-test. *P = 0.014; **P = 0.041. n = 5, WT; n = 6, VCiΔR26.Total fat weight, fat percentage from body composition measurements after six weeks of HFD, and weights of visceral fat (VF) and subcutaneous fat (SF) at the time of necropsy. Significant differences were determined using unpaired two-tailed t-test. *P = 0.006; **P = 0.001; #P = 0.008; §P = 0.006. n = 4 in each group.Food consumption during the fifth week of HFD. n = 9, WT; n = 10, VCiΔR26.Whole-mount immunofluorescence staining of blood (PECAM1, red) and lymphatic vessels (LYVE1, green) in intestinal villi and intestinal wall.Quantification of the lacteal and villus length (solid and striped color bars, respectively) and the intestinal wall LYVE1+ area percentage from images represented in (F). Significant differences were determined using unpaired two-tailed t-test. *P = 0.0002; **P = 0.00007. n = 5, WT; n = 6, VCiΔR26.Free fatty acid (FFA) and cholesterol measurements from the feces after six weeks of HFD. Significant differences were determined using unpaired two-tailed t-test. *P = 0.001; **P = 0.007. n = 5, WT; n = 6, VCiΔR26.Data information: Scale bars: 100 μm (villi) and 300 μm (intestinal wall). Data are represented as mean ± SEM.
Mentions: We further studied whether the reduction in dietary lipid absorption observed in the VCiΔR26 mice has an impact on diet-induced obesity in mice fed high-fat diet (HFD). Initial experiments in the 129SV/C57Bl/6J mixed genetic background did not reveal major differences in body weight, but indicated that the VCiΔR26 mice have an improved glucose metabolism compared to WT mice (Appendix Fig S5B and C). Interestingly, in the mixed background, the Vegfc-deleted mice had reduced serum cholesterol levels, whereas fecal cholesterol and free fatty acid (FFA) levels were increased in the VCiΔR26 mice, indicating impaired dietary lipid absorption (Appendix Fig S5D). We further performed HFD feeding experiments in the pure C57Bl/6J background, an established model of diet-induced obesity. We deleted Vegfc in 8-week-old male mice and started HFD feeding 4 weeks later. The VCiΔR26 mice gained significantly less weight and had better glucose tolerance than their WT littermates, independently of concurrent Vegfd deletion (Fig3A–C and Appendix Fig S5E and F). At necropsy after HFD, very low amounts of chyle were detected in one out of 16 Vegfc-deleted mice and in two out of five Vegfc- plus Vegfd-deleted mice, indicating mild lymphatic leakage. Body composition analysis showed that the VCiΔR26 mice had a significant reduction in total fat weight and fat percentage, but no changes in lean weight in comparison with WT littermates (Fig3D and Appendix Fig S5G). The changes in fat accumulation could not be explained by reduced caloric intake, since food consumption was similar between the VCiΔR26 and WT mice (Fig3E). As expected on the basis of our results from the mixed background, Vegfc deletion induced intestinal lymphatic vessel atrophy and increased lipid excretion into the feces also in the C57Bl/6J background (Fig3F–H). No difference in body weight was observed between WT and Vegfc-deleted mice on regular diet in which the majority of calories are derived from carbohydrate. This further indicates that the reduced body weight of the Vegfc-deleted mice on HFD is a result of reduced dietary lipid absorption.

Bottom Line: We show here that VEGF-C is necessary for perinatal lymphangiogenesis, but required for adult lymphatic vessel maintenance only in the intestine.VEGF-C was expressed by a subset of smooth muscle cells adjacent to the lacteals in the villus and in the intestinal wall.Our findings indicate that the lymphangiogenic growth factors provide trophic and dynamic regulation of the intestinal lymphatic vasculature, which could be especially important in the dietary regulation of adiposity and cholesterol metabolism.

View Article: PubMed Central - PubMed

Affiliation: Wihuri Research Institute and Translational Cancer Biology Program, Biomedicum Helsinki University of Helsinki, Helsinki, Finland.

Show MeSH
Related in: MedlinePlus