Figure 6
From: Pleiotropic roles of the matricellular protein Sparc in tendon maturation and ageing
Increased lipid accretion and adipogenic marker expression in aged tendons.
(a) mRNA levels for the adipogenic marker genes Pparγ and Cebpα were determined by quantitative RT-PCR. Shown are fold changes over mRNA levels quantified for young Achilles tendons (left) and tail tendon fascicles (right). Data represent means ± SEM of 3 independent biological replicates. (b,c) Representative immunofluorescence microscopy images and quantification of Pparγ-positive cells within the dense connective tissue of young, healthy-aged, and Sparc−/− Achilles tendons. Graphs represent mean ± SEM of percent positive cells determined for each group (n ≥ 1000 cells counted from 3 Achilles tendon samples). Scale bars: 50 μm; ***P < 0.001, One-way ANOVA (Tukey’s Multiple Comparison Test). (d) β-catenin gene expression in Achilles tendon tissue. Shown is fold-change in expression compared to young tendon tissue. Bars represent mean ± SEM (n = 5). (e) Sudan Black B staining demonstrating accumulation of lipid droplets and change in cell morphology in Sparc−/− and healthy-aged Achilles tendons. Scale bars: overview: 20 μm; insert: 10 μm; (f) Immunohistochemical detection of the lipid droplet membrane protein Perilipin-1 in young, Sparc−/−, and healthy-aged tendons. Scale bars: 10 μm.
