Journal: Arthritis & Rheumatology (Hoboken, N.j.)
Article Title: Critical Role for Transglutaminase 2 in Scleroderma Skin Fibrosis and in the Development of Dermal Sclerosis in a Mouse Model of Scleroderma
doi: 10.1002/art.43104
Figure Lengend Snippet: TGM2 gene deletion protects mice from bleomycin‐induced skin fibrosis and impacts upon primary dermal fibroblast functional activities. In (A), skin sections were stained with Masson's Trichrome and picrosirius red and dermal thickness measured using the NanoZoomer NDP software. Three measurements were taken across the skin sections and the averages skin thickness given as fold change relative to saline treated control mice. Stained sections were scanned using a NanoZoomer and viewed with the NDP viewer (×10 magnification). Data are presented as fold change in dermal thickness. * P ≤ 0.05; ** P ≤ 0.01; *** P ≤ 0.001. Bar = 200 microns. (B) Primary dermal fibroblasts were culture to confluence, and the monolayers scratched to induce a single injury in the monolayer. A zero time point following wounding (left), scratch repair after 48 hours for WT (middle), and TG2 null (right) fibroblast populations are shown. The upper panel shows migration of fibroblast after 48 hours in the absence and presence (lower panels) of TGF‐β. (C) Dermal biopsies (4 mm) were taken from 6 to 10 mice and snap frozen ready for use. Collagen content was measured using the Sircoll as per the manufacturer's instructions. The Sircoll assay is a colorimetric assay for tissue collagen against a curve of collagen reference standards. Measurements are presented as fold change relative to the saline treated controls **** P = 0.0001. Average collagen content per biopsy were WT/saline (n = 6/27.3 ug), WT/bleomycin (n = 8/41.9ug), TG2 null/saline (n = 10/40.8 ug), and TG2 null/bleomycin (n = 10/43.95 ug). Fibroblast populations derived from explant skin cultures, which were placed with 3D collagen gels (left panel), and their level of contraction was assessed at 48 hours (right panel). Contraction was determined by quantification of gel weight after contraction. Statistical significance was tested by one way ANOVA with Tukey's multiple comparison, * P < 0.05, *** P < 0.0001. Scale bar = 200 μm. ANOVA, analysis of variance; KO, knockout; TGM2, transglutaminase 2; TGF, transforming growth factor; WT, wild type. Color figure can be viewed in the online issue, which is available at http://onlinelibrary.wiley.com/doi/10.1002/art.43104/abstract .
Article Snippet: Protein bands were transferred onto nitrocellulose membranes (GE Healthcare), which were incubated in block buffer (5% nonfat dry milk, 0.1% Tween‐20 [Sigma] in phosphate‐buffered saline) for 1 hour, followed by incubation at 4°C overnight with primary antibodies against TGM2 (IA12, UCB Pharma), α‐SMA (71 ng/mL, Dako; Cat M0851/1A4), Col‐1 (0.4 μg/mL, Millipore; Cat AB78), CCN2 (0.1 μg/mL, Santa Cruz Biotechnology; Cat SC‐14939), TNC2 μg/mL (Proteintech; Cat 67710‐1), Shad 2 (Cell signaling; Cat 5678), pSmad2/3 (Cell signaling; Cat 8828), and GAPDH (0.2 μg/mL, Abcam; Cat Ab8245/6C5), diluted in block buffer.
Techniques: Functional Assay, Staining, Software, Saline, Control, Migration, Colorimetric Assay, Derivative Assay, Comparison, Knock-Out