Regulators of ECM Remodeling are Altered during Cachexia
Development
In female mice, MMP-2 mRNA abundance was ~1.1-fold
higher in the 1 wk post-LLC injection group compared to the LT or HT
groups (p<0.05; Figure 3A). MMP-9 mRNA abundance was
~2.0-3.8-fold higher in the HT group compared to all the
other groups (p<0.05; Figure 3B). Male mice saw no changes in
MMP-2 mRNA abundance with LLC-injection (p>0.05; 3C);
however, the 4 wk post-LLC injection group had an
~9.6-fold higher MMP-9 mRNA abundance compared to all
other groups (p<0.05; Figure 3D).
TGF-β-regulated Fibrosis during
Cancer Cachexia
Development
In female mice, TGF-β1 mRNA abundance was ~2.3-fold
higher in the 1wk post-LLC injection group compared to all other groups
(p<0.05; Figure 4A). We found no differences in SMAD 2 and 3
mRNA abundance (p>0.05; Figure 4B & 4C). In male mice,
there was an ~1.6-fold higher TGF-β1 mRNA abundance in
the 4 wk post-LLC injection group compared to the PBS and 1 wk post-LLC
groups (p<0.05; Figure 4D). There were no differences detected
in mRNA abundance of SMAD 3 (p>0.05; Figure 4E); however,
the 4 wk post-LLC group had a ~0.5-fold higher SMAD 2
mRNA abundance compared to the 1 wk post-LLC injection groups
(p<0.05; Figure 4G).
In vitro Analysis of Skeletal
Muscle-ECM Dynamics in a Cachectic
Environment
Myotube diameter was ~20% lower following treatment
with LCM compared to Vehicle (p<0.05; Figure 5A & 5B). There
was a main effect of myotubes to have ~4-fold less
Collagen 1 mRNA abundance compared to 3T3 fibroblasts cells
(p<0.05; Figure 6A). There was main effect of LCM treatment to
reduce Collagen 1 mRNA abundance independent of cell type
(p<0.05; Figure 6A). There was a main effect of 3T3
fibroblasts cells to have lower Collagen 3 mRNA abundance to C2C12
myotubes independent of treatment (p<0.05; Figure 6B). There
were main effects for myotubes to have a greater Collagen 3:1 ratio
independent of treatment (p<0.05: Figure 6C). Additionally,
there was a man effect for groups treated with LCM to have a higher
Collagen 3:1 ratio (p<0.05; Figure 6C). There were no
differences in mRNA abundance of MMP-2 in either myotubes or 3T3 cells
(p>0.05; Figure 6D), however mRNA abundance of MMP-9 was
~450-fold greater in 3T3 cells than in myotubes and LCM
treatment reduced MMP-9 mRNA ~200-fold in 3T3 cells
compared to Vehicle (p<0.05; Figure 6E). There was a main
effect for 3T3 cells to have lower mRNA abundance of TIMP-1 independent
of treatment (p<0.05; Figure 6F). No differences were observed
in C2C12 or 3T3 cells for protein content of β-catenin
(p>0.05; Supplemental Figure 1C).