Figure 6. Areg Improves Muscle Repair after Injury.
(A) Expression of Areg in ImmGen microarray data sets from hematopoietic-lineage cells. Mo, monocytes; MF, macrophages; DC, dendritic cells; GN, granulocytes; MDSC, myeloid-derived suppressor cells; AU, arbitrary units.
(B) Expression of Areg 2 weeks after Ctx-induced injury. Numbers represent % Foxp3+ cells that are Areg+.
(C) Volcano plots of transcriptomes of whole muscle from injured DTR+ (Treg-less) mice treated or not treated with Areg. Left: experimental protocol. Right: superimposition of transcript sets highlighted in Figure 4G and identically color-coded. Values refer to the number of genes upregulated (right) ordownregulated (left) in Areg-treated versus PBS-treated muscles. p values from a χ2 test.
(D) As in (C), except DTRT− mice were used.
(E) The same data set shown in (D) plotted as the fold-change for Areg- versus PBS-treated muscles versus the mean expression value for each transcript. Highlighted in orange and purple are genes up- ordownregulated by Areg, respectively.
(F) Myogenic clonal assay in the presence of Areg. Results were plotted as the fold-change over the mean of vehicle-control treated samples per experiment. Data represent mean ± SD and five independent experiments. **p < 0.01.
(G) Induction of satellite cells differentiation by Areg. Satellite cells were bulk-cultured in the presence of Areg or vehicle control for 12 days. Left: MyHC mRNA titered by quantitative PCR, represented as fold-change expression of Myh2 relative to vehicle control. Center: MyHC protein quantified by immunofluorescence microscopy; differentiation index calculated as the mean ratio of MyHC-positive nuclei to the total nuclei per field of view. Right: sum of DAPI-positive nuclei per well. Data represent mean ± SD and four experiments. *p < 0.05; ***p < 0.0001. See also Figure S5.