Journal: Materials Today Bio
Article Title: Extracellular biogenic nanoscale mitochondria reprogram the wound microenvironment via ROS scavenging independent of cellular uptake
doi: 10.1016/j.mtbio.2026.103023
Figure Lengend Snippet: MSC-mt mitigate oxidative damage and improve mitochondrial function in H 2 O 2 -treated skin fibroblasts. (A–B) Representative flow cytometry plots and quantification of Annexin V/PI staining for apoptosis after H 2 O 2 stimulation, showing that MSC-mt significantly reduce fibroblast apoptosis, whereas rotenone-pretreated mitochondria (mt(R)) exhibit markedly attenuated protective effects. (C–D) Representative plots and quantification of mitoSOX staining for mitochondrial ROS after 180 min H 2 O 2 exposure, showing that MSC-mt suppress mitochondrial ROS accumulation, an effect largely lost following rotenone pretreatment. (E–F) Representative plots and quantification of TMRE staining for mitochondrial membrane potential (ΔΨm) after 180 min H 2 O 2 treatment, showing preservation of mitochondrial membrane potential by MSC-mt but not by mt(R). (G–H) Representative plots and quantification of SA-β-gal staining for cellular senescence after 180 min H 2 O 2 treatment, showing reduced senescence burden in MSC-mt–treated cells, with diminished efficacy observed in the mt(R) group. (I) Representative images and quantification of colony formation assays on day 8 post-treatment, indicating improved long-term proliferative capacity following MSC-mt treatment, an effect substantially weakened following rotenone pretreatment. (J) Heatmap of differentially expressed genes identified by a wound healing PCR array following 180 min of H 2 O 2 stimulation, showing that MSC-mt partially reverse H 2 O 2 -induced transcriptional alterations associated with stress response and repair pathways, an effect attenuated when using mt(R). (K) Representative images of mouse apoptosis protein array analysis after 180 min of H 2 O 2 treatment, showing that MSC-mt partially restore the expression of key anti-apoptotic and pro-survival signaling proteins suppressed by oxidative stress, including phosphorylated AKT (Ser473), BAD (Ser112), ERK (T202), and IκBα (S32), with reduced restoration observed in the mt(R) group. (L) Western blot analysis of phosphorylated AKT at Ser473 expression after 180 min of H 2 O 2 exposure, showing restoration of pro-survival signaling by MSC-mt, which is attenuated in the mt(R) group. All experiments were independently repeated three times (n = 3). Data are presented as mean ± SEM. ∗p < 0.05; ∗∗p < 0.01; ∗∗∗p < 0.001; ns, not significant.
Article Snippet: The mitochondrial membrane potential (ΔΨm) of isolated MSC-mt was assessed using a TMRE Mitochondrial Membrane Potential Assay Kit (Beyotime, Cat# C2001S).
Techniques: Flow Cytometry, Staining, Membrane, Preserving, Protein Array, Expressing, Western Blot