Fig. 6: STARD7 induces the transformation of glycolytic fiber to oxidative fiber. | Nature Communications

Fig. 6: STARD7 induces the transformation of glycolytic fiber to oxidative fiber.

From: Rewiring of 3D chromatin topology orchestrates transcriptional reprogramming in muscle fiber-type specification and transformation

Fig. 6

a, b Immunofluorescence staining of fast-type MyHC and slow-type MyHC following STARD7 knockdown (a) and overexpression (b) in differentiated PSCs (n = 3). left panel: Representative images of immunofluorescence staining. Right panel: Statistical analysis of MYH7+ and MYH4+ fibers. Magnification, × 10, Bar = 200 µm. c, d qPCR and WB depicting the gene expression change between STARD7 knockdown and control group in differentiated PSCs (n = 3). e, f qPCR and WB showing the gene expression change between STARD7 overexpression and expression vector (EV) group in differentiated PSCs (n = 3). g, h The change of ECAR after STARD7-knockdown (g) and overexpression (h) in differentiated PSCs. Values represent the average of three independent experiments with four technical replicates for each assay. i, j The expression changes of maker genes (oxidative: COX5B, COX6B, CS, NDUFB4, PGC-1α, UQCR10; glycolytic: GPI, HK2, PKM, LDHA, LDHB; slow-type troponin: TNNC1, TNNI1, and TNNT1; fast-type troponin: TNNC2, TNNI2, and TNNT2) after STARD7 knockdown (i) and overexpression (j) in differentiated PSCs. k Representative images of GAS muscles from the left (shNC) or right (shSTARD7) hindlimbs. l, m qPCR and WB depicting of gene expression in GAS muscles from LV3-shSTARD7 and LV3-shNC groups (n = 3). n Expression changes of maker genes in GAS muscles from LV3-shSTARD7 and LV3-shNC group (n = 3 per group). o Immunofluorescence staining of fast-type myosin and slow-type myosin of GAS muscles from LV3-shSTARD7 and LV3-shNC group (n = 3 per group). Left: Representative images of immunofluorescence staining. Right: statistical analysis of the proportion changes of slow-type fibers (green) and fast-type fibers (red). Magnification, ×20, Bar = 50 µm. p–r The comparison of GAS muscle (n = 3 per group) in terms of weight, cross-sectional area, and meat color. L: lightness value; a*: redness value; b*: yellowness value. For (a–j), significance was tested by a two-tailed unpaired student’s t-test. two-sided unpaired t-test. For (l–r), significance was tested by a two-tailed paired student’s t-test. All values are presented as mean ± SEM.

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