1. Fig. 1 Irradiation with 50 Gy/3 fractions generates LAE characterized by SOD2 depletion and CTGF overexpression.
Irradiation with 50 Gy/3 fractions generates LAE characterized by SOD2 depletion and CTGF overexpression. (A) Representative photographs of bilateral superficial inferior epigastric artery (SIEA) flaps (edges tattooed in Indian ink) in Fischer (F344) male rats showing characteristic late adverse effect (LAE) features observed in irradiated flaps including contracture, induration of the skin, telangiectasia, and hair loss (n = 6 per group). (B) Changes in skin paddle surface area of irradiated and control SIEA flaps [±95% confidence interval (CI)]. (C) Acute and late RTOG scores including component subscores by tissue type: skin, subcutaneous (s/c), and joint. ROTG, Radiation Therapy Oncology Group. (D) Passive range-of-movement (ROM) measurement at the knee joint in irradiated and nonirradiated hindlimbs (n = 6 per group). (E) T2-weighted magnetic resonance imaging (MRI) of bilateral SIEA flaps showing an irradiated flap (L) and unirradiated control (R) and quantification of volumetric changes (mean ± 95% CI, n = 6 per group). fx, fractions. (F) Connective tissue growth factor (CTGF) enzyme-linked immunosorbent assay (ELISA) and superoxide dismutase 2 (SOD2) biochemical activity assay performed on flap tissues taken from irradiated and control flaps (n = 6 per group). (G) Western blotting of control and irradiated SIEA flaps for SOD2, phospho–glycogen synthase kinase 3β (GSK3β) (Ser9), β-catenin, and LEF1, with β-actin used for loading control. (H to J) Immunohistochemical analysis and quantification of collagen deposition [(H) Masson’s trichrome (collagen is green)], CTGF expression (I), and hematoxylin and eosin (H&E) staining for the assessment of fat necrosis [(J), red circle)]. Graphs represent means ± SEM of counts of collagen fibrils (H) or cells with membranous CTGF expression (I) per high-powered field (hpf) or % of section exhibiting fat necrosis (J) (n = 6 per group; scale bar, 50 μm). (K) Real-time quantitative polymerase chain reaction (RT-qPCR) for Ctgf, Col1a2, and Col3a1 gene expression (mean fold increase in gene expression ± SEM) in irradiated flap tissues (n = 6 per group). All tissue-based analyses were performed on flaps harvested at 180 days after RT. *P < 0.05, **P < 0.01, ***P < 0.001, ****P <
Aadil A. Khan et al., Sci Transl Med 2018;10:eaar2041
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