Figure 2.

Obesity impairs lymphatic transport of macromolecules to draining lymph nodes. (a) Representative hindlimb ^99mTc heat maps for NCD- and HFD-fed C57BL/6J, BALB/cJ and MSTN^ln mice. White arrows indicate the uptake in the inguinal lymph nodes (n=4/group). (b) Quantification of the rate of ^99mTc uptake in inguinal lymph nodes following hindlimb injection. Data are presented as fold change relative to their NCD controls in each group (n=16/group). C57BL/6J HFD vs NCD (*P<0.0005). MSTN^ln and BALB/cJ had no significant difference between NCD and HFD groups. (c) Quantification of peak nodal uptake of ^99mTc in inguinal lymph nodes following hindlimb injection. Data are presented as fold change relative to their NCD controls in each group (n=4/group). C57BL/6J HFD vs NCD (*P<0.05). MSTN^ln and BALB/cJ had no significant difference between NCD and HFD groups. (d) Representative Prussian blue-stained histological cross-sections of axillary lymph nodes harvested from NCD- or HFD-fed mice in all groups (scale bar=500 μm). (e) Quantification of Prussian blue staining as a percentage of the total lymph-node area in NCD- and HFD-fed mice (n=3–9/group). C57BL/6J HFD vs NCD (*P<0.05). MSTN^ln and BALB/cJ had no significant difference between NCD and HFD groups. (f) Quantification of migrating CD45.1⁺ DCs (MHCII⁺/CD11C⁺) in inguinal and popliteal lymph nodes of NCD- (open circles) and HFD- (filled circles) fed mice in all groups (n=5/group). Data are presented as fold change from respective NCD-fed controls. C57BL/6J HFD vs NCD (*P<0.05). MSTN^ln and BALB/cJ had no significant difference between NCD and HFD groups. (g) Representative dot plot graphs of inguinal/popliteal lymph node flow cytometry analyzing migrating CD45.1⁺ DCs in all groups. Red square surrounds DC population.