Journal: Redox Biology

Article Title: FTMT-mediated suppression of mitophagy links iron accumulation to osteoporosis

doi: 10.1016/j.redox.2026.104157

Figure Lengend Snippet: Iron accumulation impairs mitophagy, promotes senescence, and suppresses osteogenic differentiation in BMSCs. (a) Schematic diagram of extraction of BMSCs from human femur. (b) Western blot analysis of osteogenic marker proteins (RUNX2, ALP) in BMSCs from normal controls and postmenopausal osteoporosis patients and osteoporosis patients with iron accumulation. (c) Alizarin Red S (ARS) staining of BMSCs treated with increasing concentrations of FAC (0, 50, 100, 200 μM) for 21 days and alkaline phosphatase (ALP) staining of BMSCs treated with increasing concentrations of FAC (0, 50, 100, 200 μM) for 14 days. Scale bar: 50 μm. (d) Western blot analysis of osteogenic markers (RUNX2, ALP) in FAC-treated BMSCs for 5 days. (e) RT-qPCR analysis of osteogenic genes ( Runx2, Alpl, Bglap, Sp7 ) in FAC-treated BMSCs for 72h. (f) KEGG pathway enrichment analysis of differentially expressed genes from RNA sequencing of control and 200 μM FAC-treated BMSCs for 72h. (g, h) Immunofluorescence staining of senescence markers (γ-H2AX, H3K9me3) in FAC-treated BMSCs for 72h. Scale bar: 20 μm. (i) Senescence-associated β-galactosidase (SA-β-gal) staining of FAC-treated BMSCs for 72h. Scale bar: 50 μm. (j) Flow cytometric quantification of SA-β-gal activity in FAC-treated BMSCs for 72h. (k) Western blot analysis of senescence-related proteins (P53, P21, P16) in FAC-treated BMSCs for 72h. (l) Mitophagy assessment by immunofluorescence co-staining with Mitophagy Dye (red) and MitoTracker (green) in FAC-treated BMSCs for 72h. Scale bar: 20 μm. (m) Western blot analysis of mitophagy/autophagy-related proteins (PINK1, PARKIN, P62, LC3) in FAC-treated BMSCs for 72h. (n) Mitochondrial membrane potential (MMP) detection by MT-1 staining in FAC-treated BMSCs for 72h. Scale bar: 30 μm. Data are presented as mean ± SEM; One-way ANOVA (Dunnett's multiple-comparison test); * P < 0.05, ** P < 0.01, *** P < 0.001, **** P < 0.0001.

Article Snippet: Cells were lysed, and proteins were separated by SDS-PAGE, transferred to PVDF membranes (Millipore, IPVH00010), and probed with primary antibodies against: RUNX-2 (Abcam, ab236639), ALP (Affinity, DF6225), P53 (Affinity, AF0879), P21 (Affinity, DF6423), P16 (Abcam, ab51243), PINK1 (HUABIO, ER1706-27), PARKIN (HUABIO, ET1702-60), P62 (Abcam, ab109012), LC3 (NOVUS, NB100-2220), FTMT (Abmart, PC20086S), Phospho-PINK1[Ser228] (Cell Signaling, 89010T), Phospho-PINK1[Ser402] (Absin, abs148820), and GAPDH (Affinity, AF7021).

Techniques: Extraction, Western Blot, Marker, Staining, Quantitative RT-PCR, RNA Sequencing, Control, Immunofluorescence, Activity Assay, Membrane, Comparison

Journal: Redox Biology

Article Title: FTMT-mediated suppression of mitophagy links iron accumulation to osteoporosis

doi: 10.1016/j.redox.2026.104157

Figure Lengend Snippet: Mitophagy activation rescues iron accumulation-induced mitochondrial dysfunction, cellular senescence, and impaired osteogenic differentiation in BMSCs. BMSCs were isolated from normal mice and treated with 200 μM FAC with or without CCCP co-treatment for the same duration in each assay. The time points for the indicated assays were the same as those in . (a) Western blot analysis of mitophagy/autophagy-related proteins (PINK1, PARKIN, P62, LC3). (b, c) Flow cytometric analysis of (b) intracellular ROS and (c) mitochondrial superoxide levels. (d) Mitochondrial membrane potential assessment by MT-1 immunofluorescence staining. Scale bar: 30 μm. (e) Cellular ATP content measurement. (f – i) Immunofluorescence analysis of senescence markers (f, h) γ-H2AX and (g, i) H3K9me3. Scale bar: 40 μm. (j) Western blot analysis of senescence-related proteins (P53, P21, P16). (k) Alizarin Red S (ARS) and alkaline phosphatase (ALP) staining. Scale bar: 50 μm. (l) Western blot analysis of osteogenic marker proteins (RUNX2, ALP). Data are presented as mean ± SEM; One-way ANOVA (Tukey's multiple-comparison test); * P < 0.05, ** P < 0.01, *** P < 0.001, **** P < 0.0001.

Article Snippet: Cells were lysed, and proteins were separated by SDS-PAGE, transferred to PVDF membranes (Millipore, IPVH00010), and probed with primary antibodies against: RUNX-2 (Abcam, ab236639), ALP (Affinity, DF6225), P53 (Affinity, AF0879), P21 (Affinity, DF6423), P16 (Abcam, ab51243), PINK1 (HUABIO, ER1706-27), PARKIN (HUABIO, ET1702-60), P62 (Abcam, ab109012), LC3 (NOVUS, NB100-2220), FTMT (Abmart, PC20086S), Phospho-PINK1[Ser228] (Cell Signaling, 89010T), Phospho-PINK1[Ser402] (Absin, abs148820), and GAPDH (Affinity, AF7021).

Techniques: Activation Assay, Isolation, Western Blot, Membrane, Immunofluorescence, Staining, Marker, Comparison

Journal: Redox Biology

Article Title: FTMT-mediated suppression of mitophagy links iron accumulation to osteoporosis

doi: 10.1016/j.redox.2026.104157

Figure Lengend Snippet: Mitophagy activation alleviates BMSC senescence and restores bone mass in iron-accumulating mice. (a) Representative micro-CT images of distal femoral trabecular bone. (b) Quantitative micro-CT analysis of trabecular bone parameters: Tb.BMD (trabecular bone mineral density), BV/TV (bone volume fraction), BS/TV (bone surface density), and Tb.N (trabecular number). (c) Detection of the serum OCN and P1NP levels from the mice in each group. (d) Histological analysis of tibial sections via H&E staining, toluidine blue staining, and DAPI immunofluorescence from the mice in each group. Scale bar: 250 μm. (e) Detection of the bone formation rate by calcein double labeling from the mice in each group. Scale bar: 20 μm. (f – i) Immunofluorescence analysis of senescence markers (γ-H2AX and H3K9me3) in BMSCs isolated from different treatment groups. Scale bar: 50 μm. (j) Western blot analysis of senescence-related proteins (P53, P21, P16) in BMSCs. (k) Western blot analysis of mitophagy/autophagy-related proteins (PINK1, PARKIN, P62, LC3) in BMSCs. (l) Mitochondrial membrane potential assessment by MT-1 immunofluorescence staining in BMSCs. Scale bar: 50 μm. (m) Cellular ATP content measurement in BMSCs. (n – o) Flow cytometric analysis of (n) intracellular ROS and (o) mitochondrial superoxide levels in BMSCs. Data are presented as mean ± SEM; One-way ANOVA (Tukey's multiple-comparison test); * P < 0.05, ** P < 0.01, *** P < 0.001, **** P < 0.0001.

Article Snippet: Cells were lysed, and proteins were separated by SDS-PAGE, transferred to PVDF membranes (Millipore, IPVH00010), and probed with primary antibodies against: RUNX-2 (Abcam, ab236639), ALP (Affinity, DF6225), P53 (Affinity, AF0879), P21 (Affinity, DF6423), P16 (Abcam, ab51243), PINK1 (HUABIO, ER1706-27), PARKIN (HUABIO, ET1702-60), P62 (Abcam, ab109012), LC3 (NOVUS, NB100-2220), FTMT (Abmart, PC20086S), Phospho-PINK1[Ser228] (Cell Signaling, 89010T), Phospho-PINK1[Ser402] (Absin, abs148820), and GAPDH (Affinity, AF7021).

Techniques: Activation Assay, Micro-CT, Staining, Immunofluorescence, Labeling, Isolation, Western Blot, Membrane, Comparison

Journal: Redox Biology

Article Title: FTMT-mediated suppression of mitophagy links iron accumulation to osteoporosis

doi: 10.1016/j.redox.2026.104157

Figure Lengend Snippet: PINK1 overexpression rescues iron accumulation-induced mitochondrial dysfunction, senescence, and osteogenic impairment in BMSCs. The time points for the indicated assays were the same as those in . (a) Western blot analysis of mitophagy/autophagy-related proteins (PINK1, PARKIN, P62, LC3) in BMSCs transduced with control or PINK1-overexpressing lentivirus followed by FAC treatment. (b) Mitochondrial membrane potential assessment by MT-1 immunofluorescence staining. Scale bar: 50 μm. (c) Cellular ATP content measurement. (d, e) Flow cytometric analysis of (d) intracellular ROS and (e) mitochondrial superoxide levels. (f) Western blot analysis of senescence-related proteins (P53, P21, P16). (g – j) Immunofluorescence analysis of senescence markers (γ-H2AX and H3K9me3). Scale bar: 50 μm. (k, l) Alizarin Red S (ARS) staining and Alkaline phosphatase (ALP) staining. Scale bar: 50 μm. (m) Western blot analysis of osteogenic marker proteins (RUNX2, ALP). (n) RT-qPCR analysis of osteogenic genes ( Runx2, Alpl, Bglap, Sp7 ). Data are presented as mean ± SEM; One-way ANOVA (Tukey's multiple-comparison test); * P < 0.05, ** P < 0.01, *** P < 0.001, **** P < 0.0001.

Article Snippet: Cells were lysed, and proteins were separated by SDS-PAGE, transferred to PVDF membranes (Millipore, IPVH00010), and probed with primary antibodies against: RUNX-2 (Abcam, ab236639), ALP (Affinity, DF6225), P53 (Affinity, AF0879), P21 (Affinity, DF6423), P16 (Abcam, ab51243), PINK1 (HUABIO, ER1706-27), PARKIN (HUABIO, ET1702-60), P62 (Abcam, ab109012), LC3 (NOVUS, NB100-2220), FTMT (Abmart, PC20086S), Phospho-PINK1[Ser228] (Cell Signaling, 89010T), Phospho-PINK1[Ser402] (Absin, abs148820), and GAPDH (Affinity, AF7021).

Techniques: Over Expression, Western Blot, Transduction, Control, Membrane, Immunofluorescence, Staining, Marker, Quantitative RT-PCR, Comparison

Journal: Redox Biology

Article Title: FTMT-mediated suppression of mitophagy links iron accumulation to osteoporosis

doi: 10.1016/j.redox.2026.104157

Figure Lengend Snippet: Impaired mitophagy in BMSCs from osteoporosis patients with iron accumulation. (a) Western blot analysis of senescence-related proteins (P53, P21, P16) in BMSCs from normal controls, postmenopausal osteoporosis patients and osteoporosis patients with iron accumulation. (b) Western blot analysis of mitochondrial ferritin (FTMT) expression levels in BMSCs. (c) Western blot analysis of mitophagy/autophagy-related proteins PINK1, p-PINK1(Ser228), PARKIN, P62, and LC3 in BMSCs. (d) Western blot analysis of mitophagy/autophagy-related proteins PINK1, PARKIN, P62, and LC3 in BMSCs of PMOP and IOP group with or without CCCP intervention. (e) Western blot analysis of senescence-related proteins (P53, P21, P16) in BMSCs of PMOP and IOP group with or without CCCP intervention. (f) Western blot analysis of osteogenic marker proteins (RUNX2, ALP) in BMSCs of PMOP and IOP group with or without CCCP intervention.

Article Snippet: Cells were lysed, and proteins were separated by SDS-PAGE, transferred to PVDF membranes (Millipore, IPVH00010), and probed with primary antibodies against: RUNX-2 (Abcam, ab236639), ALP (Affinity, DF6225), P53 (Affinity, AF0879), P21 (Affinity, DF6423), P16 (Abcam, ab51243), PINK1 (HUABIO, ER1706-27), PARKIN (HUABIO, ET1702-60), P62 (Abcam, ab109012), LC3 (NOVUS, NB100-2220), FTMT (Abmart, PC20086S), Phospho-PINK1[Ser228] (Cell Signaling, 89010T), Phospho-PINK1[Ser402] (Absin, abs148820), and GAPDH (Affinity, AF7021).

Techniques: Western Blot, Expressing, Marker