Journal: Molecular Therapy. Nucleic Acids

Article Title: Ratio of miRNA-29 to miRNA-199 expression coordinates mesenchymal stem cell repair of bleomycin-induced pulmonary injury

doi: 10.1016/j.omtn.2025.102461

Figure Lengend Snippet: Bleomycin-induced lung injury, which is reduced after adipose-derived mesenchymal stem cell instillation (A) Representative μCT transverse and coronal lung sections acquired from aged (22-month-old) male C57BL/6 mice at baseline (left) and 7 days following intratracheal bleomycin (BLM, 2.0 U/kg) administration (right) demonstrating increased lung density and loss of airspaces. (B) Saline treatment did not result in evidence of lung injury on μCT scan at baseline (left) or 7 days post-instillation (right). Histological sections of lung tissue collected at day 21 post-BLM were stained with Masson’s trichrome as described in . (C and D) Representative photomicrographs (20× and 40× magnifications) of lung sections from saline-treated control mice (C) and BLM-treated mice (D). (E) Infusion of adipose-derived mesenchymal stem cells (ASCs) 12 days post-BLM instillation resulted in reduced severity of pulmonary fibrosis (PF). (F) Degree of PF on histological sections was measured by semi-quantitative Ashcroft score as described in . BLM-induced lung injury resulted in increased Ashcroft score compared to saline controls. Infusion with ASCs 12 days post-BLM injury resulted in decreased Ashcroft score. (G) Intratracheal BLM instillation increased lung collagen content as measured by hydroxyproline assays as described in . Mice treated with ASCs on day 12 post-BLM had decreased lung collagen content compared to BLM-only controls. Each data point represents an individual biological replicate (mouse); n = 6–10 mice/group. ∗ p < 0.05; ∗∗ p < 0.01; ∗∗∗ p < 0.001. (H) Ratio of pAKT to AKT protein expression in lung tissue of mice was quantified by western blot analysis at day 21 post-BLM sacrifice. Aged C57BL/6 mice treated with intratracheal BLM demonstrated increased pAKT/AKT protein expression compared to saline-treated controls. Lungs from mice treated with intravenous infusion of ASCs 12 days post-BLM-induced injury demonstrated decreased expression of pAKT/AKT compared to BLM-only group. Inset shows a representative western blot and β-actin loading control. Data are graphed as individual biological replicates ( n = 6–8 mice/group); ∗ p < 0.05.

Article Snippet: For mesenchymal differentiation potential, the Mouse Mesenchymal Stem Cell Functional Identification Kit (R&D Systems, Minneapolis, MN) was used according to the manufacturer’s instructions.

Techniques: Derivative Assay, Saline, Staining, Control, Expressing, Western Blot