human origin  (Santa Cruz Biotechnology)

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: SDF-1α decreased the number of mitochondria in chondrocytes. A . GO enrichment analysis based on RNA sequencing showing cellular metabolic changes in chondrocytes induced by SDF-1α at 200 ng/ml for 24 h. B . Representative CLSM images showing mitochondrial changes in chondrocytes after treatment with SDF-1α at 200 ng/ml for 48 h. Cells were counterstained with nuclei (DAPI, blue) and actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). C . Linear fluorescence quantification showing the distribution of mitochondria in chondrocytes (B). D . Total fluorescence quantification (per cell), validating the mitochondrial area in chondrocytes (B). Data were derived from six replicates based on three independent experiments ( n = 3). E . Representative western blot images showing changes in Cs protein levels in chondrocytes treated with SDF-1α at different concentrations for 48 h. Images were obtained from three independent experiments ( n = 3). F . Quantification of Cs protein in chondrocytes (E). Data were obtained from three independent experiments ( n = 3). G . Representative TEM images showing the changes in mitochondrial number in chondrocytes induced by SDF-1α at 200 ng/ml for 48 h. Boxed areas (right panels) display enlarged fields to allow clearer visualization of individual mitochondria (indicated by arrows). Images were obtained from four independent experiments ( n = 4). H . Quantification of the mitochondrial number (per cell) in chondrocytes (G). Data are based on five cells per group from three independent experiments (n = 3). Data in C , D , F , and H are presented as the mean ± SD. Significance analyses in D and H were based on Two-tailed Student’s t-tests. Data in F were analyzed using a one-way ANOVA. Statistical significance ( p ) value < 0.05.

Article Snippet: For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h or 10 μM CC (HY-13418 A, MedChemExpress) for 1 h before SDF-1α exposure [ ].

Techniques: RNA Sequencing, Fluorescence, Derivative Assay, Western Blot, Two Tailed Test

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: SDF-1α causes an imbalance in mitochondrial dynamics. A . Representative TEM images showing changes in mitochondrial morphology in chondrocytes induced by SDF-1α at 200 ng/ml for 48 h. Images were obtained from three independent experiments ( n = 3). B . Quantification of mitochondrial morphology in chondrocytes (A). The data are presented based on three independent experiments ( n = 3). C . Representative CLSM images showing the mitochondrial changes in chondrocytes induced by SDF-1α at 200 ng/ml for 48 h. Cyan boxes indicate morphological changes in mitochondrial networks by ImageJ. Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). D . Quantification of mitochondrial branch junctions and mean branch length (per cell) in chondrocytes (C). Data are presented as seven cells per group from three independent experiments ( n = 3). E . Representative western blot images showing changes in Mfn1, Mfn2, Opa1, Drp1, and Fis1 in chondrocytes treated with SDF-1α at different concentrations for 48 h. Images were obtained from three independent experiments ( n = 3). F . Quantification of Mfn1, Mfn2, Opa1, Drp1 and Fis1 in chondrocytes (E). Data were obtained from three independent experiments ( n = 3). G . ATP assay showing ATP content in chondrocytes treated with SDF-1α for 48 h, presented as nmol/mg protein after normalization to total protein measured by BCA. Data were obtained from three independent experiments ( n = 3). H . Representative CLSM images showing Drp1 changes in chondrocytes after treatment with SDF-1α at 200 ng/ml for 48 h. Cells were counterstained with nuclei (DAPI, blue) and actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). I . Linear fluorescence quantification showing the distribution of Drp1 in the chondrocytes (H). Data in B , D , F , G , and I are presented as the mean ± SD. Significance analyses in B and D were based on Two-tailed Student’s t-tests. Data in F and G were analyzed using a one-way ANOVA. Statistical significance ( p ) value < 0.05.

Article Snippet: For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h or 10 μM CC (HY-13418 A, MedChemExpress) for 1 h before SDF-1α exposure [ ].

Techniques: Western Blot, ATP Assay, Fluorescence, Two Tailed Test

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: SDF-1α promotes mitophagy in chondrocytes. A . Representative CLSM images showing changes in mitochondria (red) and LC3B (green) expression in chondrocytes induced by SDF-1α at 200 ng/ml for 48 h. Cells were counterstained with nuclei (DAPI, blue). Images were obtained from three independent experiments ( n = 3). B . Linear fluorescence quantification showing the distribution of mitochondria and LC3B in chondrocytes (A). Purple arrows indicate colocalization peaks of the mitochondria and LC3B. C . Statistical analysis illustrating changes in colocalized proportions of LC3B and mitochondria in chondrocytes induced by SDF-1α at 200 ng/ml for 48 h. Data are based on three independent experiments ( n = 3). D . mRFP-GFP-LC3 adenovirus double-label assay showing changes in autophagic flux in chondrocytes induced by SDF-1α at 200 ng/ml for 48 h. Free red dots represent autolysosomes (indicated by red arrows). Yellow dots represent autophagosomes (indicated by yellow arrows). Images were selected from three independent experiments ( n = 3). E . Quantification of autolysosomes and autophagosomes (per cell) in chondrocytes (D). Data are based on six cells per group from three independent experiments ( n = 3). F . Representative western blot images showing changes in Bnip3, LC3B, p62, Parkin, and PINK1 in chondrocytes treated with SDF-1α at different concentrations for 48 h. Images were obtained from three independent experiments ( n = 3). G. Quantification of Bnip3, LC3B, p62, Parkin, and PINK1 in chondrocytes (F). Data were obtained from three independent experiments ( n = 3). H . Representative western blot images showing changes in PGC1α in chondrocytes treated with SDF-1α at different concentrations for 48 h. Images were obtained from three independent experiments ( n = 3). I . Quantification of PGC1α in chondrocytes (H). Data were obtained from three independent experiments ( n = 3). Data in C , E , G , and I are presented as the mean ± SD. Significance analysis in E was based on Two-tailed Student’s t-test. Data in G and I were based on one-way ANOVA. Statistical significance ( p ) value < 0.05.

Article Snippet: For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h or 10 μM CC (HY-13418 A, MedChemExpress) for 1 h before SDF-1α exposure [ ].

Techniques: Expressing, Fluorescence, Western Blot, Two Tailed Test

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: SDF-1α promotes activation of AMPKα signaling in chondrocytes. A . Schematic diagram illustrating AMPKα signaling-mediated mitochondrial function. B . Protein–protein interaction network demonstrating the impact of AMPKα signaling on mitochondrial dynamics and mitophagy. C . Representative western blot images showing changes in AMPKα and p-AMPKα in chondrocytes treated with SDF-1α at different concentrations for 6 h. Images were obtained from three independent experiments ( n = 3). D . Quantification of p-AMPKα in chondrocytes (C). Data were obtained from three independent experiments ( n = 3). E . Representative CLSM images showing changes in the nuclear translocation of p-AMPKα in chondrocytes induced by SDF-1α at 200 ng/ml for 6 h. Cells were counterstained with nuclei (DAPI, blue) and actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). F . Total fluorescence quantification (per cell) confirming the expression of p-AMPKα in chondrocytes (E). Data were obtained from 19 replicates of three independent experiments ( n = 3). G . Linear fluorescence quantification illustrating the distribution of p-AMPKα in the chondrocytes (E). H . Representative CLSM images showing mitochondrial alterations in chondrocytes pretreated with CC (10 μM, 1 h) and subsequently stimulated with SDF-1α (200 ng/ml, 48 h). Cyan boxes indicate morphological changes in the mitochondrial networks. Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). I . Quantification of mitochondrial branch junctions and mean branch length (per cell) in chondrocytes (H). The data were based on eight replicates from three independent experiments. Data in D , F , G , and I are presented as the mean ± SD. Significance analysis in F was based on Two-tailed Student’s t-test. Data in D and I were based on one-way ANOVA. Statistical significance ( p ) value < 0.05.

Article Snippet: For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h or 10 μM CC (HY-13418 A, MedChemExpress) for 1 h before SDF-1α exposure [ ].

Techniques: Activation Assay, Western Blot, Translocation Assay, Fluorescence, Expressing, Two Tailed Test

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: SDF-1α regulates mitochondrial dynamics via CXCR4. A . Schematic depicting the entry of SDF-1α into chondrocytes mainly via CXCR4. B . Representative western blot images showing changes in Cs protein in chondrocytes by knockdown of CXCR4 in the presence of SDF-1α at 200 ng/ml for 48 h. Images were obtained from three independent experiments ( n = 3). C . Representative CLSM images showing mitochondrial changes in chondrocytes after CXCR4 knockdown in the presence of SDF-1α at 200 ng/ml for 48 h. Cyan boxes indicate morphological changes in the mitochondrial networks. Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). D . Quantification of mitochondrial branch junctions and mean branch length (per cell) in chondrocytes (C). The data were based on eight replicates from three independent experiments. E . Representative western blotting images showing changes in Mfn1, Mfn2, Opa1, Drp1, and Fis1 in chondrocytes after CXCR4 knockdown in the presence of SDF-1α at 200 ng/ml for 48 h. Images were obtained from three independent experiments ( n = 3). F . Quantification of Mfn1, Mfn2, Opa1, Drp1, and Fis1 proteins in chondrocytes (E). Data were obtained from three independent experiments ( n = 3). G . Representative CLSM images showing Drp1 changes in chondrocytes following knockdown of CXCR4 in the presence of SDF-1α at 200 ng/ml for 48 h. Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). H . Total fluorescence quantification (per cell) confirming the expression of Drp1 in chondrocytes (G). Data were obtained from 18 replicates derived from three independent experiments ( n = 3). I . Linear fluorescence quantification illustrating the distribution of Drp1 in chondrocytes (G). J . Representative CLSM images showing p-AMPKα changes in chondrocytes following knockdown of CXCR4 in the presence of SDF-1α at 200 ng/ml for 6 h. Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). K . Total fluorescence quantification (per cell) confirming the expression of p-AMPKα in chondrocytes (J). Data were obtained from 16 replicates of three independent experiments ( n = 3). L . Linear fluorescence quantification showing the distribution of p-AMPKα in chondrocytes (J). Data in D , F , H , I , K , and L are presented as the mean ± SD. Significance analyses in D , F , H , and K were based on one-way ANOVA. Statistical significance ( p ) value < 0.05.

Article Snippet: For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h or 10 μM CC (HY-13418 A, MedChemExpress) for 1 h before SDF-1α exposure [ ].

Techniques: Western Blot, Knockdown, Fluorescence, Expressing, Derivative Assay

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: SDF-1α promotes MAPK/ERK signaling in chondrocytes. A . KEGG pathway analysis based on RNA sequencing showing upregulated pathways in chondrocytes induced by SDF-1α at 200 ng/ml for 24 h. B . Representative western blot images showing changes in ERK, p-ERK, JNK, p-JNK, p38, and p-p38 in chondrocytes treated with SDF-1α at different concentrations for 1 h. Images were obtained from three independent experiments ( n = 3). C . Quantification of p-ERK, p-JNK and p-p38 in chondrocytes (B). Data were obtained from three independent experiments ( n = 3). D . Representative western blotting images showing changes in ERK, p-ERK, AMPKα, and p-AMPKα in chondrocytes after CXCR4 knockdown in the presence of SDF-1α at 200 ng/ml for 6 h. Images were obtained from three independent experiments ( n = 3). E . Quantification of p-ERK and p-AMPKα in chondrocytes (D). Data were obtained from three independent experiments ( n = 3). F . Representative western blot images showing changes in ERK, p-ERK, AMPKα, and p-AMPKα in chondrocytes induced by SDF-1α at 200 ng/ml for 6 h in the presence or absence of PD98059 (10 μM). Images were obtained from three independent experiments ( n = 3). G . Quantification of p-ERK and p-AMPKα in chondrocytes (F). Data were obtained from three independent experiments ( n = 3). H . Representative CLSM images showing p-AMPKα changes in chondrocytes pretreated with PD98059 (10 μM, 2 h) and subsequently stimulated with SDF-1α (200 ng/ml, 6 h). Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). I . Total fluorescence quantification (per cell) confirming the expression of p-AMPKα in chondrocytes (H). Data were obtained from 14 replicates derived from three independent experiments ( n = 3). J . Linear fluorescence quantification illustrating the distribution of p-AMPKα in chondrocytes (H). Data in C , E , G , I , and J are presented as the mean ± SD. Significance analyses in C , E , G , and I were based on one-way ANOVA. Statistical significance ( p ) value < 0.05.

Article Snippet: For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h or 10 μM CC (HY-13418 A, MedChemExpress) for 1 h before SDF-1α exposure [ ].

Techniques: RNA Sequencing, Western Blot, Knockdown, Fluorescence, Expressing, Derivative Assay

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: SDF-1α regulates mitochondrial dynamics via MAPK/ERK signaling. A . Representative western blot images showing changes in Cs in chondrocytes pretreated with PD98059 (10 μM, 2 h) and subsequently stimulated with SDF-1α (200 ng/ml, 48 h). Images were obtained from three independent experiments ( n = 3). B . Quantification of Cs in chondrocytes in (A). Data were obtained from three independent experiments ( n = 3). C . Representative CLSM images showing mitochondrial changes in chondrocytes pretreated with PD98059 (10 μM, 2 h) and subsequently stimulated with SDF-1α (200 ng/ml, 48 h). Cyan boxes indicate morphological changes in the mitochondrial networks. Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). D . Quantification of mitochondrial branch junctions and mean branch length (per cell) in chondrocytes (C). The data are based on eight cells per group from three independent experiments. E . Representative western blot images showing changes in Mfn1, Mfn2, Opa1, Drp1, and Fis1 in chondrocytes pretreated with PD98059 (10 μM, 2 h) and subsequently stimulated with SDF-1α (200 ng/ml, 48 h). Images were selected from three independent experiments ( n = 3). F . Quantification of Mfn1, Mfn2, Opa1, Drp1, and Fis1 in chondrocytes (E). Data were obtained from three independent experiments ( n = 3). G . Representative CLSM images showing Drp1 changes in chondrocytes pretreated with PD98059 (10 μM, 2 h) and subsequently stimulated with SDF-1α (200 ng/ml, 48 h). Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). H . Total fluorescence quantification (per cell) confirming the expression of Drp1 in chondrocytes (G). Data were obtained from 12 replicates of three independent experiments ( n = 3). I . Linear fluorescence quantification illustrating the distribution of Drp1 in chondrocytes (G). Data in B , D , F , H , and I are presented as the mean ± SD. Significance analyses in B , D , F , and H were based on one-way ANOVA. Statistical significance ( p ) value < 0.05.

Article Snippet: For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h or 10 μM CC (HY-13418 A, MedChemExpress) for 1 h before SDF-1α exposure [ ].

Techniques: Western Blot, Fluorescence, Expressing

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: Schematic diagram showing the regulatory mechanism of mitochondrial dynamics in chondrocytes induced by SDF-1α. This work demonstrates that SDF-1α signals through CXCR4 to activate p-ERK signaling, thereby promoting the phosphorylation and nuclear translocation of p-AMPKα. This signaling cascade promotes mitochondrial fission and mitophagy and reduces mitochondrial fusion in chondrocytes. Collectively, these findings establish that SDF-1α/CXCR4 regulates mitochondrial dynamics in chondrocytes via the ERK/AMPKα axis.

Article Snippet: For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h or 10 μM CC (HY-13418 A, MedChemExpress) for 1 h before SDF-1α exposure [ ].

Techniques: Phospho-proteomics, Translocation Assay

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: SDF-1α decreased the number of mitochondria in chondrocytes. A . GO enrichment analysis based on RNA sequencing showing cellular metabolic changes in chondrocytes induced by SDF-1α at 200 ng/ml for 24 h. B . Representative CLSM images showing mitochondrial changes in chondrocytes after treatment with SDF-1α at 200 ng/ml for 48 h. Cells were counterstained with nuclei (DAPI, blue) and actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). C . Linear fluorescence quantification showing the distribution of mitochondria in chondrocytes (B). D . Total fluorescence quantification (per cell), validating the mitochondrial area in chondrocytes (B). Data were derived from six replicates based on three independent experiments ( n = 3). E . Representative western blot images showing changes in Cs protein levels in chondrocytes treated with SDF-1α at different concentrations for 48 h. Images were obtained from three independent experiments ( n = 3). F . Quantification of Cs protein in chondrocytes (E). Data were obtained from three independent experiments ( n = 3). G . Representative TEM images showing the changes in mitochondrial number in chondrocytes induced by SDF-1α at 200 ng/ml for 48 h. Boxed areas (right panels) display enlarged fields to allow clearer visualization of individual mitochondria (indicated by arrows). Images were obtained from four independent experiments ( n = 4). H . Quantification of the mitochondrial number (per cell) in chondrocytes (G). Data are based on five cells per group from three independent experiments (n = 3). Data in C , D , F , and H are presented as the mean ± SD. Significance analyses in D and H were based on Two-tailed Student’s t-tests. Data in F were analyzed using a one-way ANOVA. Statistical significance ( p ) value < 0.05.

Article Snippet: Chondrocytes were treated with 50, 100, and 200 ng/ml SDF-1α for 1, 6, 24, or 48 h. For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h before SDF-1α exposure.

Techniques: RNA Sequencing, Fluorescence, Derivative Assay, Western Blot, Two Tailed Test

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: SDF-1α causes an imbalance in mitochondrial dynamics. A . Representative TEM images showing changes in mitochondrial morphology in chondrocytes induced by SDF-1α at 200 ng/ml for 48 h. Images were obtained from three independent experiments ( n = 3). B . Quantification of mitochondrial morphology in chondrocytes (A). The data are presented based on three independent experiments ( n = 3). C . Representative CLSM images showing the mitochondrial changes in chondrocytes induced by SDF-1α at 200 ng/ml for 48 h. Cyan boxes indicate morphological changes in mitochondrial networks by ImageJ. Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). D . Quantification of mitochondrial branch junctions and mean branch length (per cell) in chondrocytes (C). Data are presented as seven cells per group from three independent experiments ( n = 3). E . Representative western blot images showing changes in Mfn1, Mfn2, Opa1, Drp1, and Fis1 in chondrocytes treated with SDF-1α at different concentrations for 48 h. Images were obtained from three independent experiments ( n = 3). F . Quantification of Mfn1, Mfn2, Opa1, Drp1 and Fis1 in chondrocytes (E). Data were obtained from three independent experiments ( n = 3). G . ATP assay showing ATP content in chondrocytes treated with SDF-1α for 48 h, presented as nmol/mg protein after normalization to total protein measured by BCA. Data were obtained from three independent experiments ( n = 3). H . Representative CLSM images showing Drp1 changes in chondrocytes after treatment with SDF-1α at 200 ng/ml for 48 h. Cells were counterstained with nuclei (DAPI, blue) and actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). I . Linear fluorescence quantification showing the distribution of Drp1 in the chondrocytes (H). Data in B , D , F , G , and I are presented as the mean ± SD. Significance analyses in B and D were based on Two-tailed Student’s t-tests. Data in F and G were analyzed using a one-way ANOVA. Statistical significance ( p ) value < 0.05.

Article Snippet: Chondrocytes were treated with 50, 100, and 200 ng/ml SDF-1α for 1, 6, 24, or 48 h. For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h before SDF-1α exposure.

Techniques: Western Blot, ATP Assay, Fluorescence, Two Tailed Test

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: SDF-1α promotes mitophagy in chondrocytes. A . Representative CLSM images showing changes in mitochondria (red) and LC3B (green) expression in chondrocytes induced by SDF-1α at 200 ng/ml for 48 h. Cells were counterstained with nuclei (DAPI, blue). Images were obtained from three independent experiments ( n = 3). B . Linear fluorescence quantification showing the distribution of mitochondria and LC3B in chondrocytes (A). Purple arrows indicate colocalization peaks of the mitochondria and LC3B. C . Statistical analysis illustrating changes in colocalized proportions of LC3B and mitochondria in chondrocytes induced by SDF-1α at 200 ng/ml for 48 h. Data are based on three independent experiments ( n = 3). D . mRFP-GFP-LC3 adenovirus double-label assay showing changes in autophagic flux in chondrocytes induced by SDF-1α at 200 ng/ml for 48 h. Free red dots represent autolysosomes (indicated by red arrows). Yellow dots represent autophagosomes (indicated by yellow arrows). Images were selected from three independent experiments ( n = 3). E . Quantification of autolysosomes and autophagosomes (per cell) in chondrocytes (D). Data are based on six cells per group from three independent experiments ( n = 3). F . Representative western blot images showing changes in Bnip3, LC3B, p62, Parkin, and PINK1 in chondrocytes treated with SDF-1α at different concentrations for 48 h. Images were obtained from three independent experiments ( n = 3). G. Quantification of Bnip3, LC3B, p62, Parkin, and PINK1 in chondrocytes (F). Data were obtained from three independent experiments ( n = 3). H . Representative western blot images showing changes in PGC1α in chondrocytes treated with SDF-1α at different concentrations for 48 h. Images were obtained from three independent experiments ( n = 3). I . Quantification of PGC1α in chondrocytes (H). Data were obtained from three independent experiments ( n = 3). Data in C , E , G , and I are presented as the mean ± SD. Significance analysis in E was based on Two-tailed Student’s t-test. Data in G and I were based on one-way ANOVA. Statistical significance ( p ) value < 0.05.

Article Snippet: Chondrocytes were treated with 50, 100, and 200 ng/ml SDF-1α for 1, 6, 24, or 48 h. For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h before SDF-1α exposure.

Techniques: Expressing, Fluorescence, Western Blot, Two Tailed Test

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: SDF-1α promotes activation of AMPKα signaling in chondrocytes. A . Schematic diagram illustrating AMPKα signaling-mediated mitochondrial function. B . Protein–protein interaction network demonstrating the impact of AMPKα signaling on mitochondrial dynamics and mitophagy. C . Representative western blot images showing changes in AMPKα and p-AMPKα in chondrocytes treated with SDF-1α at different concentrations for 6 h. Images were obtained from three independent experiments ( n = 3). D . Quantification of p-AMPKα in chondrocytes (C). Data were obtained from three independent experiments ( n = 3). E . Representative CLSM images showing changes in the nuclear translocation of p-AMPKα in chondrocytes induced by SDF-1α at 200 ng/ml for 6 h. Cells were counterstained with nuclei (DAPI, blue) and actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). F . Total fluorescence quantification (per cell) confirming the expression of p-AMPKα in chondrocytes (E). Data were obtained from 19 replicates of three independent experiments ( n = 3). G . Linear fluorescence quantification illustrating the distribution of p-AMPKα in the chondrocytes (E). H . Representative CLSM images showing mitochondrial alterations in chondrocytes pretreated with CC (10 μM, 1 h) and subsequently stimulated with SDF-1α (200 ng/ml, 48 h). Cyan boxes indicate morphological changes in the mitochondrial networks. Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). I . Quantification of mitochondrial branch junctions and mean branch length (per cell) in chondrocytes (H). The data were based on eight replicates from three independent experiments. Data in D , F , G , and I are presented as the mean ± SD. Significance analysis in F was based on Two-tailed Student’s t-test. Data in D and I were based on one-way ANOVA. Statistical significance ( p ) value < 0.05.

Article Snippet: Chondrocytes were treated with 50, 100, and 200 ng/ml SDF-1α for 1, 6, 24, or 48 h. For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h before SDF-1α exposure.

Techniques: Activation Assay, Western Blot, Translocation Assay, Fluorescence, Expressing, Two Tailed Test

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: SDF-1α regulates mitochondrial dynamics via CXCR4. A . Schematic depicting the entry of SDF-1α into chondrocytes mainly via CXCR4. B . Representative western blot images showing changes in Cs protein in chondrocytes by knockdown of CXCR4 in the presence of SDF-1α at 200 ng/ml for 48 h. Images were obtained from three independent experiments ( n = 3). C . Representative CLSM images showing mitochondrial changes in chondrocytes after CXCR4 knockdown in the presence of SDF-1α at 200 ng/ml for 48 h. Cyan boxes indicate morphological changes in the mitochondrial networks. Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). D . Quantification of mitochondrial branch junctions and mean branch length (per cell) in chondrocytes (C). The data were based on eight replicates from three independent experiments. E . Representative western blotting images showing changes in Mfn1, Mfn2, Opa1, Drp1, and Fis1 in chondrocytes after CXCR4 knockdown in the presence of SDF-1α at 200 ng/ml for 48 h. Images were obtained from three independent experiments ( n = 3). F . Quantification of Mfn1, Mfn2, Opa1, Drp1, and Fis1 proteins in chondrocytes (E). Data were obtained from three independent experiments ( n = 3). G . Representative CLSM images showing Drp1 changes in chondrocytes following knockdown of CXCR4 in the presence of SDF-1α at 200 ng/ml for 48 h. Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). H . Total fluorescence quantification (per cell) confirming the expression of Drp1 in chondrocytes (G). Data were obtained from 18 replicates derived from three independent experiments ( n = 3). I . Linear fluorescence quantification illustrating the distribution of Drp1 in chondrocytes (G). J . Representative CLSM images showing p-AMPKα changes in chondrocytes following knockdown of CXCR4 in the presence of SDF-1α at 200 ng/ml for 6 h. Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). K . Total fluorescence quantification (per cell) confirming the expression of p-AMPKα in chondrocytes (J). Data were obtained from 16 replicates of three independent experiments ( n = 3). L . Linear fluorescence quantification showing the distribution of p-AMPKα in chondrocytes (J). Data in D , F , H , I , K , and L are presented as the mean ± SD. Significance analyses in D , F , H , and K were based on one-way ANOVA. Statistical significance ( p ) value < 0.05.

Article Snippet: Chondrocytes were treated with 50, 100, and 200 ng/ml SDF-1α for 1, 6, 24, or 48 h. For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h before SDF-1α exposure.

Techniques: Western Blot, Knockdown, Fluorescence, Expressing, Derivative Assay

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: SDF-1α promotes MAPK/ERK signaling in chondrocytes. A . KEGG pathway analysis based on RNA sequencing showing upregulated pathways in chondrocytes induced by SDF-1α at 200 ng/ml for 24 h. B . Representative western blot images showing changes in ERK, p-ERK, JNK, p-JNK, p38, and p-p38 in chondrocytes treated with SDF-1α at different concentrations for 1 h. Images were obtained from three independent experiments ( n = 3). C . Quantification of p-ERK, p-JNK and p-p38 in chondrocytes (B). Data were obtained from three independent experiments ( n = 3). D . Representative western blotting images showing changes in ERK, p-ERK, AMPKα, and p-AMPKα in chondrocytes after CXCR4 knockdown in the presence of SDF-1α at 200 ng/ml for 6 h. Images were obtained from three independent experiments ( n = 3). E . Quantification of p-ERK and p-AMPKα in chondrocytes (D). Data were obtained from three independent experiments ( n = 3). F . Representative western blot images showing changes in ERK, p-ERK, AMPKα, and p-AMPKα in chondrocytes induced by SDF-1α at 200 ng/ml for 6 h in the presence or absence of PD98059 (10 μM). Images were obtained from three independent experiments ( n = 3). G . Quantification of p-ERK and p-AMPKα in chondrocytes (F). Data were obtained from three independent experiments ( n = 3). H . Representative CLSM images showing p-AMPKα changes in chondrocytes pretreated with PD98059 (10 μM, 2 h) and subsequently stimulated with SDF-1α (200 ng/ml, 6 h). Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). I . Total fluorescence quantification (per cell) confirming the expression of p-AMPKα in chondrocytes (H). Data were obtained from 14 replicates derived from three independent experiments ( n = 3). J . Linear fluorescence quantification illustrating the distribution of p-AMPKα in chondrocytes (H). Data in C , E , G , I , and J are presented as the mean ± SD. Significance analyses in C , E , G , and I were based on one-way ANOVA. Statistical significance ( p ) value < 0.05.

Article Snippet: Chondrocytes were treated with 50, 100, and 200 ng/ml SDF-1α for 1, 6, 24, or 48 h. For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h before SDF-1α exposure.

Techniques: RNA Sequencing, Western Blot, Knockdown, Fluorescence, Expressing, Derivative Assay

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: SDF-1α regulates mitochondrial dynamics via MAPK/ERK signaling. A . Representative western blot images showing changes in Cs in chondrocytes pretreated with PD98059 (10 μM, 2 h) and subsequently stimulated with SDF-1α (200 ng/ml, 48 h). Images were obtained from three independent experiments ( n = 3). B . Quantification of Cs in chondrocytes in (A). Data were obtained from three independent experiments ( n = 3). C . Representative CLSM images showing mitochondrial changes in chondrocytes pretreated with PD98059 (10 μM, 2 h) and subsequently stimulated with SDF-1α (200 ng/ml, 48 h). Cyan boxes indicate morphological changes in the mitochondrial networks. Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). D . Quantification of mitochondrial branch junctions and mean branch length (per cell) in chondrocytes (C). The data are based on eight cells per group from three independent experiments. E . Representative western blot images showing changes in Mfn1, Mfn2, Opa1, Drp1, and Fis1 in chondrocytes pretreated with PD98059 (10 μM, 2 h) and subsequently stimulated with SDF-1α (200 ng/ml, 48 h). Images were selected from three independent experiments ( n = 3). F . Quantification of Mfn1, Mfn2, Opa1, Drp1, and Fis1 in chondrocytes (E). Data were obtained from three independent experiments ( n = 3). G . Representative CLSM images showing Drp1 changes in chondrocytes pretreated with PD98059 (10 μM, 2 h) and subsequently stimulated with SDF-1α (200 ng/ml, 48 h). Cells were counterstained with nuclei (DAPI, blue) and the actin cytoskeleton (F-actin, green). Images were obtained from three independent experiments ( n = 3). H . Total fluorescence quantification (per cell) confirming the expression of Drp1 in chondrocytes (G). Data were obtained from 12 replicates of three independent experiments ( n = 3). I . Linear fluorescence quantification illustrating the distribution of Drp1 in chondrocytes (G). Data in B , D , F , H , and I are presented as the mean ± SD. Significance analyses in B , D , F , and H were based on one-way ANOVA. Statistical significance ( p ) value < 0.05.

Article Snippet: Chondrocytes were treated with 50, 100, and 200 ng/ml SDF-1α for 1, 6, 24, or 48 h. For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h before SDF-1α exposure.

Techniques: Western Blot, Fluorescence, Expressing

Journal: Cell Communication and Signaling : CCS

Article Title: The SDF-1α/CXCR4 axis regulates chondrocyte mitochondrial dynamics via the ERK/AMPKα pathway

doi: 10.1186/s12964-026-02827-x

Figure Lengend Snippet: Schematic diagram showing the regulatory mechanism of mitochondrial dynamics in chondrocytes induced by SDF-1α. This work demonstrates that SDF-1α signals through CXCR4 to activate p-ERK signaling, thereby promoting the phosphorylation and nuclear translocation of p-AMPKα. This signaling cascade promotes mitochondrial fission and mitophagy and reduces mitochondrial fusion in chondrocytes. Collectively, these findings establish that SDF-1α/CXCR4 regulates mitochondrial dynamics in chondrocytes via the ERK/AMPKα axis.

Article Snippet: Chondrocytes were treated with 50, 100, and 200 ng/ml SDF-1α for 1, 6, 24, or 48 h. For inhibition experiments, cells were preincubated with 10 μM PD98059 (HY-12028, MedChemExpress) for 2 h before SDF-1α exposure.

Techniques: Phospho-proteomics, Translocation Assay