Fig. 3

iMSCs promoted engraftment of Hu5/KD3 human myogenic cells in TA muscle of NSG-mdx^4Cv mice. A Experimental design of cotransplantation. Hu5/KD3 cells were cocultured with iMSCs or BM-MSCs in the Transwell system for 4 days before transplantation. The control group received only intramuscular injection of human myogenic Hu5/KD3 cells into the left TA muscle. The experimental groups received both intramuscular injection (IM) of Hu5/KD3 cells into the left TA muscle and intraperitoneal injection (IP) of BM-MSCs or iMSCs (with the same type of MSCs used for coculture). The right TA muscle in all groups was injected with 10% Matrigel/PBS (-). B Experimental schedule of transplantation. Fifty microliters of 1.2% BaCl₂ was injected into the TA muscles on both sides 24 h (day 1) before transplantation of Hu5/KD3 cells to induce muscle regeneration. Hu5/KD3 cells were directly injected into the left TA muscle at day 0. MSCs were injected into the peritoneal cavity of the NSG-mdx^4Cv mice or NOD/SCID mice at days 0, 7, 14, and 21. The mice were killed at day 28. C Representative immunohistochemistry of cross sections of TA muscles of NSG-mdx^4Cv transplanted with Hu5/KD3 cells (left), Hu5/KD cells cocultured with iMSCs for 4 days (middle), and Hu5/KD3 cells cocultured with iMSCs and co-transplanted with iMSCs (IP)(right). The muscle sections were stained with anti-human lamin A/C (green), anti-dystrophin (red), and DAPI. Scale bar, 100 μm. D Numbers of human lamin A/C(+) dystrophin(+) myofibers/section of TA muscles of NSG-mdx^4Cv injected with Hu5/KD3 cells with or without MSCs. PBS: TA muscle injected with PBS. Hu5/KD3: TA muscle injected with Hu5/KD3 cells. Hu5/KD3 + iMSCs: Hu5/KD3 cells co-cultured and co-transplanted with iMSCs. Hu5KD3 + BM-MSCs: Hu5/KD3 cells co-cultured and co-transplanted with BM-MSCs. iMSCs coculture: Hu5/KD3 cells co-cultured with iMSCs and transplanted into TA muscle. Means ± SEMs. Tukey’s multiple comparisons test