Journal: Microbiology Spectrum

Article Title: Mechanism of Action of Isopropoxy Benzene Guanidine against Multidrug-Resistant Pathogens

doi: 10.1128/spectrum.03469-22

Figure Lengend Snippet: IBG restores the sensitivity of colistin against Gram-negative bacteria. (A) Chemical structure of the IBG. The guanidine group is marked in red. (B) Inhibition rate of colistin combined with IBG against 30 Gram-negative bacteria. (C and D) Time-kill assays conducted with colistin (0.5× MIC), IBG monotherapy (10 μg/mL), the combination, or later addition of colistin or IBG against colistin-susceptible E. coli ATCC 25922 (C) and colistin-resistant E. coli SHP45 (D).

Article Snippet: We found that colistin monotherapy produced highly resistant strains with a 64-fold increase in the MIC for ATCC 25922 and strains with a 4-fold increase in the MIC for SHP45.

Techniques: Bacteria, Inhibition

Journal: Microbiology Spectrum

Article Title: Mechanism of Action of Isopropoxy Benzene Guanidine against Multidrug-Resistant Pathogens

doi: 10.1128/spectrum.03469-22

Figure Lengend Snippet: Antibacterial activity of IBG ^a

Article Snippet: We found that colistin monotherapy produced highly resistant strains with a 64-fold increase in the MIC for ATCC 25922 and strains with a 4-fold increase in the MIC for SHP45.

Techniques: Activity Assay, Bacteria

Journal: Microbiology Spectrum

Article Title: Mechanism of Action of Isopropoxy Benzene Guanidine against Multidrug-Resistant Pathogens

doi: 10.1128/spectrum.03469-22

Figure Lengend Snippet: Evolution of colistin resistance in colistin-susceptible and colistin-resistant E. coli . The fold change of colistin MIC was detected after colistin-susceptible E. coli ATCC 25922 (A) and colistin-resistant E. coli SHP45 (B) were treated with 0.5× MIC colistin alone or in combination with IBG at 5 μg/mL or 10 μg/mL in vitro .

Article Snippet: We found that colistin monotherapy produced highly resistant strains with a 64-fold increase in the MIC for ATCC 25922 and strains with a 4-fold increase in the MIC for SHP45.

Techniques: In Vitro

Journal: Microbiology Spectrum

Article Title: Mechanism of Action of Isopropoxy Benzene Guanidine against Multidrug-Resistant Pathogens

doi: 10.1128/spectrum.03469-22

Figure Lengend Snippet: Antibacterial mechanism of IBG against MDR bacteria. (A) Dynamic curves of the outer membrane probed with NPN in E. coli ATCC 25922 treated with IBG (10 μg/mL), colistin (0.12 μg/mL), and both together. The fluorescence was detected with excitation and emission wavelengths of 350 nm and 420 nm. (B) The ΔpH after treatment with different concentrations of IBG (from 0 to 10× MIC) was determined in S. aureus ATCC 29213. The means for three biological replicates are shown, and error bars represent the SD. (C) Levels of intracellular ATP in S. aureus ATCC 29213 after treatment of IBG. Nonparametric one-way analysis of variance (ANOVA) was used to calculate P values (*, P < 0.05; **, P < 0.01). (D) Accumulation of ROS in E. coli ATCC 25922 treated with IBG with or without 0.12 μg/mL colistin. (E) IBG inhibits the transcript level of mcr -1 in E. coli SHP45 determined by qRT-PCR. All data are means and SD, and significance was determined by nonparametric one-way ANOVA (**, P < 0.01). (F) Scheme of mechanisms of action of IBG in Gram-positive and Gram-negative bacteria.

Article Snippet: We found that colistin monotherapy produced highly resistant strains with a 64-fold increase in the MIC for ATCC 25922 and strains with a 4-fold increase in the MIC for SHP45.

Techniques: Bacteria, Membrane, Fluorescence, Quantitative RT-PCR

Journal: BMC Cancer

Article Title: Unveiling GDF15 as a promising biomarker for predicting survival in pancreatic ductal carcinoma: a retrospective research

doi: 10.1186/s12885-025-14963-7

Figure Lengend Snippet: IHC results of GDF15 level in PDAC and normal pancreas tissues. a Immunohistochemical analysis revealed markedly elevated GDF15 expression in pancreatic ductal adenocarcinoma (PDAC) specimens, whereas adjacent non‑neoplastic pancreatic tissues showed little to no detectable GDF15 staining. b Patients with poor prognoses exhibited higher expression levels compared to those with more favorable outcomes. c H‑score results for GDF15 expression were graphically represented, revealing a statistically significant difference in staining intensity between PDAC tumor tissues and their adjacent non‑neoplastic counterparts

Article Snippet: The TMAs were prepared using a PV-9000 IHC kit (ZSGB-BIO, Beijing, China) and incubated with an anti-GDF15 antibody (27455-1-AP; Proteintech, Wuhan, China).

Techniques: Immunohistochemical staining, Expressing, Staining

Journal: BMC Cancer

Article Title: Unveiling GDF15 as a promising biomarker for predicting survival in pancreatic ductal carcinoma: a retrospective research

doi: 10.1186/s12885-025-14963-7

Figure Lengend Snippet: OS of PDAC patients with different GDF15 levels. Patients exhibiting low GDF15 expression showed significantly longer overall survival than those with high expression, as demonstrated by Kaplan–Meier analysis.

Article Snippet: The TMAs were prepared using a PV-9000 IHC kit (ZSGB-BIO, Beijing, China) and incubated with an anti-GDF15 antibody (27455-1-AP; Proteintech, Wuhan, China).

Techniques: Expressing

Journal: Redox Biology

Article Title: Repression of oxidative phosphorylation by NR2F2, MTERF3 and GDF15 in human skin under high-glucose stress

doi: 10.1016/j.redox.2025.103613

Figure Lengend Snippet: GDF15 biosynthesis is indispensable for human skin reconstruction . A) The effect of 100 nM GDF15 supplementation was determined using comparative proteomics on HDFs exposed to 12 mM glucose for 48H . The pathway analysis is shown as a bubble volcano plot (significant pathways with -logAdjPvalue>1.3 are shown. The pathways with blue dots are inhibited while pathways with orange dots are activated. The number of proteins detected for each pathway is represented by the diameter of each dot. Activation or inhibition was determined using the Z-score calculated by IPA Qiagen. B) Proteins of the Wound Healing Signaling, AMPK Signaling, Oxidative Phosphorylation or Protein Kinase A Signaling altered by the 12 mM glucose treatment are shown. C ) Human skin reconstruction was performed using fiboblasts expressing a shGDF15, wild-type fibroblasts exposed to 12 mM glucose or wild-type fibroblasts exposed to 12 mM glucose and supplemented with 2 nM GDF15. development. Macroscopic view is shown with a scale bar of 0.6 cm, D) Immunofluorescence study of HRS using DAPI marker (blue), Collagen I (yellow) and MKi67 (pink). Scale bar. 50 μM, N = 3. E , F ) Migration assay of HDF cultivated in 5.55 mM, 12 mM or 25 mM glucose and HDF cultivated in 12 mM glucose supplemented with 100 nM gdf15, HDF transfected with esiGDF15 or esiTFAM (N = 15). All data were expressed as the mean ± SEM. ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001. Ordinary one-way ANOVA with Dunett's test correction was used for panel F.

Article Snippet: Expression plasmids in lentiviral vectors were purchased for MTERF3 Human Tagged ORF Clone (#RC201030L4, Origene) and GDF15 Human Tagged ORF Clone (#RC201295L2, Origene).

Techniques: Activation Assay, Inhibition, Phospho-proteomics, Expressing, Immunofluorescence, Marker, Migration, Transfection

Journal: Redox Biology

Article Title: Repression of oxidative phosphorylation by NR2F2, MTERF3 and GDF15 in human skin under high-glucose stress

doi: 10.1016/j.redox.2025.103613

Figure Lengend Snippet: cFOS and NR2F2 transcription factors mediate glucose-dependent repression of GDF15 in human dermis. A) Determination by Simple WES of the protein expression level of proGDF15 in wild-type HDF expressing shcontrol or shGDF15 (N = 3). B) Expression of GDF15 in the skin from human protein expression atlas from EMBL-EBI ( https://www.ebi.ac.uk ) which includes RNA-seq analyses from tissue samples of 122 human individuals, representing 32 different tissues. The results are expressed as TPM (Transcripts Per Kilobase Million). C) Quantification of GDF15 mRNA transcripts by taqman quantitative PCR in HDF, A549 and HEPG2 (N = 3). D) Quantification of GDF15 mRNA transcripts by taqman quantitative PCR in HDF, 786-O and SN005 cells (N = 3). E) ELISA-Based Quantification of GDF15 secretion in HDFs. HDFs were cultured under conditions of normal (5.5 mM) and high (12 mM) glucose concentrations during 48h. GDF15 levels in the culture supernatants were quantified using an enzyme-linked immunosorbent assay (ELISA) following the manufacturer's instructions. F) Quantification of GDF15 mRNA transcripts by taqman quantitative PCR in HDF grown in 5.55 mM, 12 mM or 25 mM glucose (N = 3). G) GDF15 promoter activity in HDF grown 24 h in DMEM with 5.55 mM,12 mM or 25 mM of glucose or 5.55 mM of galactose (N = 4). H) Dose-dependent relationship between GDF15 promoter activation and glucose concentration in the medium. I) GDF15 gene promoter sequence with identification of the binding site for the FOS transcription factor (Swiss Regulon Expasy). J) Quantification of FOS mRNA transcript by taqman quantitative PCR in HDF cultivated in 5.55 mM or 12 mM glucose (N = 3). K) Determination by Simple WES of FOS protein expression level in HDF cultivated in 5.55 mM or 12 mM glucose (N = 3). L-M) Determination by Simple WES of GDF15 protein expression level in HDF transfected with esiFOS (N = 3). N) Quantification of GDF15 mRNA transcript by taqman quantitative PCR in HDF transfected with esiNR2F2 (N = 3). O) Quantification of GDF15 mRNA transcript by taqman quantitative PCR in HDF expressing sgControl, sgRNA 1 targeting NR2F2 and sgRNA2 targeting NR2F2. Normalization of the data to GusB (β-glucuronidase), N = 3. P–S) Quantification of ATF3, ATF4, CHOP and P53 mRNA transcripts by taqman quantitative PCR in HDF expressing siCTRL and esiNR2F2 in 5.5 mM glucose or 12 mM glucose growth medium. Normalization of the data to GusB (β-glucuronidase), N = 3. T) Schematic representation of the NR2F2-MTERF3-GDF15 axis and its control on OXPHOS function in response to glucose stress. All data are expressed as the mean ± SEM. ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001. Ordinary one-way ANOVA with Dunett's test correction was used for panel C, E and N. Unpaired t -test was used for panels A, B, H, I, J, K, L and M.

Article Snippet: Expression plasmids in lentiviral vectors were purchased for MTERF3 Human Tagged ORF Clone (#RC201030L4, Origene) and GDF15 Human Tagged ORF Clone (#RC201295L2, Origene).

Techniques: Expressing, RNA Sequencing, Real-time Polymerase Chain Reaction, Enzyme-linked Immunosorbent Assay, Cell Culture, Activity Assay, Activation Assay, Concentration Assay, Sequencing, Binding Assay, Transfection, Control

Journal: Redox Biology

Article Title: Repression of oxidative phosphorylation by NR2F2, MTERF3 and GDF15 in human skin under high-glucose stress

doi: 10.1016/j.redox.2025.103613

Figure Lengend Snippet: GDF15 inhibition by hyperglycemia or shRNA alters mitochondrial biogenesis. A) Metabolomic profile of HDF grown 48H in DMEM with 5.55 mM or 12 mM + 100 nM GDF15 of glucose and HDF expressing a shGDF15 cultivated in 5.55 mM glucose (N = 3). B) Oxygen consumption rate (OCR) was measured using the Seahorse XFe96. Routine respiration and uncoupled respiration (CCCP) were determined in HDF grown in 5.55 mM glucose and HDF expressing shGDF15 grown in 5.55 mM glucose or 5.55 mM glucose supplemented with 100 nM gdf15. C) Oxygen consumption rate (OCR) was measured using the Seahorse XFe96. Routine respiration and uncoupled respiration (CCCP) were determined in HDF grown in 5.55 mM glucose and supplemented with low doses of gdf15: 20pM, 80pM, 1 nM, 10 nM and 100 nM. D) Mitochondrial respiratory chain proteins (gene loci) specifically activated at the level of chromatin accessibility by GDF15 100 nM. E-H) Quantification of mRNA transcripts by taqman quantitative PCR for NR2F2, GDF15, MTERF3 and TFAM in HDF cultivated with 5.55 mM glucose or 5.55 mM glucose supplemented with 100 nM gdf15. Normalization of the data was performed to GusB (β-glucuronidase), N = 3. I-L) Quantification of mRNA transcripts by taqman quantitative PCR for GDF15, MAPK1, MAPK3, PGC1α (Peroxisome proliferator-activated receptor-gamma coactivator 1 alpha) in HDF cultivated with 5.55 mM glucose supplemented with low doses of gdf15. Normalization of the data was performed to GusB (β-glucuronidase), N = 3 M) Quantification of TFAM mRNA transcripts by taqman quantitative PCR in HDF cultivated with 5.55 mM, 12 mM or 25 mM glucose or in HDF expressing shGDF15 grown in 5.55 mM glucose. Normalization of data was performed to GusB (β-glucuronidase), N = 3. N) Quantification of PGC1α mRNA transcript by taqman quantitative PCR in HDF cultivated with 5.55 mM, 12 mM or 25 mM glucose or in HDF expressing shGDF15 grown in 5.55 mM glucose. Normalization of the data to GusB (β-glucuronidase), N = 3. O) Quantification of PGC1α mRNA transcript by taqman quantitative PCR in HDF transfected with esiNR2F2. Normalization of data to GusB (β-glucuronidase), N = 3. P,Q) Quantification of the total Coenzyme Q10 (oxidized and reduced forms) in HDF cultivated with 5.55 mM, 12 mM or 12 mM glucose medium supplemented with 100 nM gdf15. Analysis was also performed in HDF expressing shGDF15 in 5.55 mM glucose. R) Quantification of TFAM in HDF cultivated with 5.55 mM glucose medium or medium supplemented with 20pM, 100 pM and 100 nM rGDF15. S) Summary of the regulatory network linking TFAM, PGC1α, COQ9 and COQ10. All data are expressed as the mean ± SEM. ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001. Ordinary one-way ANOVA with Dunett's test correction was used for panel A, B, F, G, I-M, P–R. Unpaired t -test was used for panels E, H and O.

Article Snippet: Expression plasmids in lentiviral vectors were purchased for MTERF3 Human Tagged ORF Clone (#RC201030L4, Origene) and GDF15 Human Tagged ORF Clone (#RC201295L2, Origene).

Techniques: Inhibition, shRNA, Expressing, Real-time Polymerase Chain Reaction, Transfection

Journal: Redox Biology

Article Title: GDF15 nanotherapy ameliorates NLRP3-associated redox imbalance and cardiac injury in sepsis

doi: 10.1016/j.redox.2025.103897

Figure Lengend Snippet: Multifaceted validation of GDF15 changes in serum from SICM patients and their clinical associations. (A) GDF15 levels were quantified using the Luminex platform. (B) A volcano plot illustrated the gene expression distribution of GDF15 among differentially expressed genes (DEGs) in whole blood. (C) A heatmap displayed the expression profiles of GDF15 and inflammatory cytokines. (D) Serum GDF15 levels in patients. (E) Pearson correlation analysis demonstrated the association between GDF15 and SOFA score, as well as EF. (F) ROC curves were plotted to assess the diagnostic accuracy of GDF15 and SOFA score in identifying SICM. (G) Multivariate logistic regression analysis was performed to identify independent risk factors for the development of SICM in septic patients. ∗p < 0.05 indicates significant differences; ns: no significant differences.

Article Snippet: Enzyme-linked immunosorbent assays (ELISA) were conducted using commercial kits to quantify serum levels of human GDF15 (Proteintech, Cat# KE00108), mouse GDF15 (Proteintech, Cat# KE10082), and mouse IL-6 (MULTI SCIENCES, Cat# EK206).

Techniques: Biomarker Discovery, Luminex, Gene Expression, Expressing, Diagnostic Assay

Journal: Redox Biology

Article Title: GDF15 nanotherapy ameliorates NLRP3-associated redox imbalance and cardiac injury in sepsis

doi: 10.1016/j.redox.2025.103897

Figure Lengend Snippet: Upregulation of GDF15 in the SICM model. (A) A schematic workflow for the establishment of the SICM model in C57BL/6J mice via intraperitoneal injection of LPS or saline. (B) Cardiac contractile function parameters, including EF and FS. (C) Serum levels of GDF15 and IL-6. (D) Histopathological analysis of heart tissue, H&E staining (left) and immunohistochemical staining for Ly6G and CD68 (right). Black arrows indicate inflammatory cell infiltration; scale bar: 50 μm. (E) Western blot analysis of GDF15 protein expression in heart tissue. n = 4. (F) qPCR analysis of Gdf15 , Bnp , Il-1β , Il-6 , Icam-1 and Vcam- 1 mRNA levels in heart tissue. (G) Identification of GDF15-positive cells in single-cell RNA-sequencing dataset ( GSE190856 ). (H) qPCR analysis of Gdf15 and Il-1β , Il-6, Nos2, Ptgs2 mRNA expression in BMDM after LPS stimulation. ∗p < 0.05 indicates significant differences; n = 6 per group.

Article Snippet: Enzyme-linked immunosorbent assays (ELISA) were conducted using commercial kits to quantify serum levels of human GDF15 (Proteintech, Cat# KE00108), mouse GDF15 (Proteintech, Cat# KE10082), and mouse IL-6 (MULTI SCIENCES, Cat# EK206).

Techniques: Injection, Saline, Staining, Immunohistochemical staining, Western Blot, Expressing, RNA Sequencing

Journal: Redox Biology

Article Title: GDF15 nanotherapy ameliorates NLRP3-associated redox imbalance and cardiac injury in sepsis

doi: 10.1016/j.redox.2025.103897

Figure Lengend Snippet: GDF15 deficiency exacerbates LPS-induced SICM in mice. (A) Schematic workflow for the establishment of the SICM model in Gdf15 −/− mice. Gdf15 −/− mice were intraperitoneally injected with LPS or saline to induce SICM, with tissue samples collected 24 h post-injection for further analysis. (B) Echocardiographic assessment of EF and FS. (C) H&E staining of heart tissue, black arrows indicate inflammatory cell infiltration. scale bar: 50 μm. (D) CD68 immunofluorescence staining of heart tissue. Blue staining highlights nuclei, red staining identifies CD68 + macrophages; scale bar: 20 μm. (E) qPCR analysis of mRNA expression levels of Bnp , Il-1β, Il-6, and Mcp-1 in heart tissue. n = 6 per group.

Article Snippet: Enzyme-linked immunosorbent assays (ELISA) were conducted using commercial kits to quantify serum levels of human GDF15 (Proteintech, Cat# KE00108), mouse GDF15 (Proteintech, Cat# KE10082), and mouse IL-6 (MULTI SCIENCES, Cat# EK206).

Techniques: Injection, Saline, Staining, Immunofluorescence, Expressing

Journal: Redox Biology

Article Title: GDF15 nanotherapy ameliorates NLRP3-associated redox imbalance and cardiac injury in sepsis

doi: 10.1016/j.redox.2025.103897

Figure Lengend Snippet: MGP exerts anti-inflammatory effects via the MYPT1/AKT/YBX-1 signaling pathway. (A) IP-MS of BMDM to identify the interaction with GDF15. MYPT1 is marked in red. (B) Z-DOCK predicted the interaction domain between GDF15 and MYPT1. Pink represents GDF15, green represents MYPT1, and the boxed region indicates the binding domain. (C) Co-IP combined with Western blot analysis of GDF-15 and MYPT1 binding in macrophages after LPS treatment. (n = 3). (D) Immunofluorescence detection of co-localization between GDF15 (green) and MYPT1 (red), with blue staining for nuclei. Scale bar: 20 μm. (E) Protein expression levels of p -YBX-1, YBX-1, and p -AKT, AKT in BMDM after LPS and/or MGP treatment, with gray-scale intensity analysis of relative expression differences. (F) Representative immunofluorescence images of YBX-1 staining in BMDM after LPS and/or MGP treatment. Blue staining highlights nuclei, and red staining identifies YBX-1. Scale bar: 20 μm ∗p < 0.05, significantly different from control group. #p < 0.05, significantly different from LPS group. n = 6 per group.

Article Snippet: Enzyme-linked immunosorbent assays (ELISA) were conducted using commercial kits to quantify serum levels of human GDF15 (Proteintech, Cat# KE00108), mouse GDF15 (Proteintech, Cat# KE10082), and mouse IL-6 (MULTI SCIENCES, Cat# EK206).

Techniques: Protein-Protein interactions, Binding Assay, Co-Immunoprecipitation Assay, Western Blot, Immunofluorescence, Staining, Expressing, Control

Journal: Redox Biology

Article Title: GDF15 nanotherapy ameliorates NLRP3-associated redox imbalance and cardiac injury in sepsis

doi: 10.1016/j.redox.2025.103897

Figure Lengend Snippet: YBX-1 mediates GDF15-mediated transcriptional regulation of the NLRP3 pathway. (A) qPCR analysis of mRNA expression levels of Nlrp3, Asc , and Il-1β in LPS-stimulated BMDM after Si- Ybx-1 . (B) Western blot analysis of protein expression levels of NLRP3 and IL-1β in LPS-stimulated BMDM after YBX-1 knockdown. (C) qPCR analysis of mRNA expression levels of Nlrp3 and Il-1β in LPS and MGP-treated BMDM after YBX-1 knockdown. (D) Schematic diagram of the luciferase reporter plasmid for the Nlrp3 promoter. (E) Luciferase activity of pcDNA3.1-YBX-1 or empty vector-transfected cells. (F) Luciferase activity after LPS and MGP treatment. n = 6 per group.

Article Snippet: Enzyme-linked immunosorbent assays (ELISA) were conducted using commercial kits to quantify serum levels of human GDF15 (Proteintech, Cat# KE00108), mouse GDF15 (Proteintech, Cat# KE10082), and mouse IL-6 (MULTI SCIENCES, Cat# EK206).

Techniques: Expressing, Western Blot, Knockdown, Luciferase, Plasmid Preparation, Activity Assay, Transfection

Journal: Redox Biology

Article Title: GDF15 nanotherapy ameliorates NLRP3-associated redox imbalance and cardiac injury in sepsis

doi: 10.1016/j.redox.2025.103897

Figure Lengend Snippet: Mechanism of action of macrophage-biomimetic nanocarriers delivering GDF15 to target the YBX-1-NLRP3 axis in SICM. Macrophage-biomimetic nanocarriers loaded with rhGDF15 are targeted to inflammatory sites in the heart, enhancing local drug accumulation, while GDF15 binds to MYPT1 to inhibit YBX-1 phosphorylation and block its nuclear translocation, leading to reduced nuclear YBX-1 expression and decreased transcriptional activity of the Nlrp3 promoter, which suppresses NLRP3 inflammasome assembly and pro-inflammatory cytokine release such as IL-1β, ultimately alleviating macrophage inflammatory responses, myocardial cell injury, and improving cardiac function in SICM.

Article Snippet: Enzyme-linked immunosorbent assays (ELISA) were conducted using commercial kits to quantify serum levels of human GDF15 (Proteintech, Cat# KE00108), mouse GDF15 (Proteintech, Cat# KE10082), and mouse IL-6 (MULTI SCIENCES, Cat# EK206).

Techniques: Phospho-proteomics, Blocking Assay, Translocation Assay, Expressing, Activity Assay

Journal: Frontiers in Immunology

Article Title: GDF15 orchestrates mitochondrial-immune crosstalk via SMAD7-HIF-1α-PKM2 cascade to attenuate septic liver injury

doi: 10.3389/fimmu.2025.1712741

Figure Lengend Snippet: LPS challenge induces time-dependent mitochondrial dysfunction and metabolic stress with compensatory GDF15 upregulation in liver injury (A) Temporal liver histopathology (H&E) post-LPS. Scale bar: 50 μm. (Time-resolved hepatic damage progression.) (B) Serum ALT/AST kinetics (n = 3). Data: mean ± SD. Study groups and individual replicates are identified in the figure key. ***p < 0.001. (Biomarker-confirmed hepatocyte injury.) (C) Progressive loss of hepatic UQCRC1 (mitochondrial complex III core subunit). β-actin: loading control.(Impaired mitochondrial electron transport.) (D) Time-elevated serum TNF-α, IL-6, and lactate in mice (n = 5). Study groups and individual replicates are identified in the figure key. ***p < 0.001. (Concomitant systemic inflammation and metabolic stress.) (E) Time-elevated cell culture supernatant TNF-α, IL-6, and lactate (n = 5). ***p < 0.001. (Concomitant inflammation and metabolic stress in cell culture system.) (F) Spatiotemporal GDF15-F4/80 co-localization in liver. GDF15 (orange), macrophages (F4/80, green), nuclei (DAPI, blue). Scale bar: 20 μm. Representative image showing focal GDF15 induction. Note that the signal is localized to discrete macrophage-enriched inflammatory niches, consistent with the physiological distribution of immune cells in hepatic tissue. (G) Hepatic GDF15 accumulation after LPS challenge. β-actin served as a loading control. Note: the detected band at ~34 kDa corresponds to the glycosylated pro-form of GDF15. (Liver-wide stress adaptation response.) (H) Persistent UQCRC1 suppression in hepatocytes (validating in vivo impairment in C).(Cell-level mitochondrial dysfunction.) (I) GDF15 induction in RAW264.7 cells. β-actin: loading control. (Cell-autonomous GDF15 upregulation.).

Article Snippet: Proteins (30 μg/lane) were separated on 10% SDS-PAGE gels, transferred to PVDF membranes (Millipore, IPVH00010), and probed with the following primary antibodies: rabbit anti-mouse UQCRC1 (Proteintech, Cat. No. 21705-1-AP, 1:1000), rabbit anti-mouse GDF15 (Proteintech, Cat. No. 27455-1-AP, 1:1000), rabbit anti-mouse HIF-1α (Proteintech, Cat. No. 20960-1-AP, 1:1000), rabbit anti-mouse SMAD7 (Proteintech, Cat. No. 725840-1-AP, 1:1000), mouse anti-mouse PKM2 (Proteintech, Cat. No. 60268-1-Ig, 1:1000), rabbit anti-mouse H3 (Proteintech, Cat. No. 17168-1-AP, 1:5000) and mouse anti-mouse β-actin (Proteintech, Cat. No. 66009-1-Ig, 1:5000).

Techniques: Histopathology, Biomarker Discovery, Control, Cell Culture, In Vivo

Journal: Frontiers in Immunology

Article Title: GDF15 orchestrates mitochondrial-immune crosstalk via SMAD7-HIF-1α-PKM2 cascade to attenuate septic liver injury

doi: 10.3389/fimmu.2025.1712741

Figure Lengend Snippet: Hepatoprotective effects of GDF15 overexpression against LPS-induced injury via mitochondrial function restoration. (A) Robust GDF15 expression in mouse liver following rAAV8-mGdf15 delivery. β-actin: loading control.(rAAV8-mediated hepatic GDF15 overexpression. β-actin: loading control.) (B) H&E-stained liver sections: Untreated (NC), LPS-challenged (LPS), and LPS + rAAV8-mGdf15 (LPS+GDF15). Scale bar: 50 μm. (Histopathological rescue by GDF15.) (C) TUNEL assay (green) showing apoptotic cell death. DAPI (blue): nuclei. GDF15 significantly reduces apoptosis. Scale bars: 20 μm.(GDF15-mediated suppression of apoptosis. TUNEL cells (green), nuclei (DAPI, blue).) (D) Macrophage infiltration (F4/80+, green) attenuated by GDF15 overexpression. DAPI (blue): nuclei. Scale bars: 100 μm.(Inhibition of macrophage recruitment. F4/80+ cells (green), nuclei (DAPI, blue).) (E) Hepatic UQCRC1 recovery with GDF15. β-actin: loading control.(Mitochondrial complex III rescue.) (F) Serum TNF-α, IL-6, and lactate levels (n = 5). Study groups and individual replicates are identified in the figure key. ***p < 0.001. (Systemic inflammation and metabolic stress reversal.) (G) rAAV8-mGdf15 elevates GDF15 in RAW264.7. β-actin: loading control.(Macrophage-targeted GDF15 overexpression.) (H) Effective GDF15 knockdown (si-GDF15) in RAW264.7. β-actin: loading control.(GDF15 knockdown efficiency.) (I) UQCRC1 expression in RAW264.7: Loss of GDF15 (si-GDF15) exacerbates LPS-induced UQCRC1 suppression, while GDF15 restores it.(GDF15-dependent mitochondrial protection in macrophages.) (J) Inflammatory (TNF-α, IL-6) and metabolic (lactate) markers in RAW264.7 supernatant (n = 5 independent experiments). GDF15 inhibits LPS-induced release; si-GDF15 amplifies it. Study groups and individual replicates are identified in the figure key.(GDF15-modulated macrophage inflammatory output.).

Article Snippet: Proteins (30 μg/lane) were separated on 10% SDS-PAGE gels, transferred to PVDF membranes (Millipore, IPVH00010), and probed with the following primary antibodies: rabbit anti-mouse UQCRC1 (Proteintech, Cat. No. 21705-1-AP, 1:1000), rabbit anti-mouse GDF15 (Proteintech, Cat. No. 27455-1-AP, 1:1000), rabbit anti-mouse HIF-1α (Proteintech, Cat. No. 20960-1-AP, 1:1000), rabbit anti-mouse SMAD7 (Proteintech, Cat. No. 725840-1-AP, 1:1000), mouse anti-mouse PKM2 (Proteintech, Cat. No. 60268-1-Ig, 1:1000), rabbit anti-mouse H3 (Proteintech, Cat. No. 17168-1-AP, 1:5000) and mouse anti-mouse β-actin (Proteintech, Cat. No. 66009-1-Ig, 1:5000).

Techniques: Over Expression, Expressing, Control, Staining, TUNEL Assay, Inhibition, Knockdown

Journal: Frontiers in Immunology

Article Title: GDF15 orchestrates mitochondrial-immune crosstalk via SMAD7-HIF-1α-PKM2 cascade to attenuate septic liver injury

doi: 10.3389/fimmu.2025.1712741

Figure Lengend Snippet: GDF15 preserves mitochondrial homeostasis in LPS-stimulated macrophages through dual regulation of SMAD7 and PKM2 pathways. (A) HIF-1α and SMAD7 expression in RAW264.7 macrophages across conditions: Untreated, LPS, LPS with rAAV8-mGdf15 overexpression (LPS+GDF15), and LPS with GDF15 knockdown (si-GDF15). β-actin: loading control.(HIF-1α suppression and SMAD7 induction by GDF15.) (B) Cytosolic and nuclear PKM2 protein levels. Lamin B1 (nuclear) and α-tubulin (cytosolic) markers validate fractionation efficiency. Study groups and individual replicates are identified in the figure key.(PKM2 subcellular redistribution modulated by GDF15.) (C) Immunofluorescence of PKM2 (red) and nuclei (DAPI, blue). Arrows indicate nuclear PKM2 accumulation. Scale bar: 15 μm.(Nuclear PKM2 enrichment upon LPS challenge mitigated by GDF15 and exacerbated by GDF15 knockdown.).

Article Snippet: Proteins (30 μg/lane) were separated on 10% SDS-PAGE gels, transferred to PVDF membranes (Millipore, IPVH00010), and probed with the following primary antibodies: rabbit anti-mouse UQCRC1 (Proteintech, Cat. No. 21705-1-AP, 1:1000), rabbit anti-mouse GDF15 (Proteintech, Cat. No. 27455-1-AP, 1:1000), rabbit anti-mouse HIF-1α (Proteintech, Cat. No. 20960-1-AP, 1:1000), rabbit anti-mouse SMAD7 (Proteintech, Cat. No. 725840-1-AP, 1:1000), mouse anti-mouse PKM2 (Proteintech, Cat. No. 60268-1-Ig, 1:1000), rabbit anti-mouse H3 (Proteintech, Cat. No. 17168-1-AP, 1:5000) and mouse anti-mouse β-actin (Proteintech, Cat. No. 66009-1-Ig, 1:5000).

Techniques: Expressing, Over Expression, Knockdown, Control, Fractionation, Immunofluorescence

Journal: Frontiers in Immunology

Article Title: GDF15 orchestrates mitochondrial-immune crosstalk via SMAD7-HIF-1α-PKM2 cascade to attenuate septic liver injury

doi: 10.3389/fimmu.2025.1712741

Figure Lengend Snippet: HIF-1α and PKM2 are critical effectors of GDF15-driven mitochondrial protection and anti-inflammatory responses. (A) HIF-1α inhibition by BAY 87-2243 (5 μM, 24 h). β-actin: loading control.(Pharmacological HIF-1α blockade.) (B) PKM2 inhibition by Shikonin (2 μM, 24 h). β-actin: loading control.(PKM2 activity suppression.) (C) UQCRC1 recovery in LPS-injured macrophages treated with: GDF15 overexpression, HIF-1α inhibitor (BAY), or PKM2 inhibitor (Shikonin). β-actin: loading control.(Mitochondrial complex III rescue via HIF-1α/PKM2 inhibition mirrors GDF15 effects.) (D) Inflammatory (TNF-α, IL-6) and metabolic (lactate) markers in cell supernatant (n = 5). Study groups and individual replicates are identified in the figure key. ***p < 0.001.(HIF-1α/PKM2 targeting replicates GDF15-mediated anti-inflammatory and metabolic homeostasis.) (E) UQCRC1 expression under GDF15 loss-of-function: si-GDF15 alone vs. combined with BAY 87–2243 or Shikonin. β-actin: loading control. Study groups and individual replicates are identified in the figure key.(Mitochondrial rescue in GDF15-deficient macrophages requires HIF-1α/PKM2 inhibition.) (F) Supernatant cytokines and lactate in si-GDF15 macrophages with/without inhibitors (n = 5). ***p < 0.001. (Inflammation reversal in GDF15-knockdown macrophages depends on HIF-1α/PKM2 blockade.).

Article Snippet: Proteins (30 μg/lane) were separated on 10% SDS-PAGE gels, transferred to PVDF membranes (Millipore, IPVH00010), and probed with the following primary antibodies: rabbit anti-mouse UQCRC1 (Proteintech, Cat. No. 21705-1-AP, 1:1000), rabbit anti-mouse GDF15 (Proteintech, Cat. No. 27455-1-AP, 1:1000), rabbit anti-mouse HIF-1α (Proteintech, Cat. No. 20960-1-AP, 1:1000), rabbit anti-mouse SMAD7 (Proteintech, Cat. No. 725840-1-AP, 1:1000), mouse anti-mouse PKM2 (Proteintech, Cat. No. 60268-1-Ig, 1:1000), rabbit anti-mouse H3 (Proteintech, Cat. No. 17168-1-AP, 1:5000) and mouse anti-mouse β-actin (Proteintech, Cat. No. 66009-1-Ig, 1:5000).

Techniques: Inhibition, Control, Activity Assay, Over Expression, Expressing, Knockdown

Journal: Frontiers in Immunology

Article Title: GDF15 orchestrates mitochondrial-immune crosstalk via SMAD7-HIF-1α-PKM2 cascade to attenuate septic liver injury

doi: 10.3389/fimmu.2025.1712741

Figure Lengend Snippet: SMAD7 activation suppresses HIF-1α to mediate GDF15-dependent mitochondrial protection in LPS-challenged macrophages. (A) Pharmacological SMAD7 activation by Asiaticoside (20 μM, 48 h). β-actin: loading control. (B) HIF-1α expression under LPS challenge: LPS alone, LPS + AVV-GDF15, or LPS + SMAD7 activation (Asiaticoside). β-actin: loading control. (C) HIF-1α modulation across conditions: LPS, LPS + si-GDF15, LPS + Asiaticoside, or LPS + si-GDF15 + Asiaticoside. β-actin: loading control.

Article Snippet: Proteins (30 μg/lane) were separated on 10% SDS-PAGE gels, transferred to PVDF membranes (Millipore, IPVH00010), and probed with the following primary antibodies: rabbit anti-mouse UQCRC1 (Proteintech, Cat. No. 21705-1-AP, 1:1000), rabbit anti-mouse GDF15 (Proteintech, Cat. No. 27455-1-AP, 1:1000), rabbit anti-mouse HIF-1α (Proteintech, Cat. No. 20960-1-AP, 1:1000), rabbit anti-mouse SMAD7 (Proteintech, Cat. No. 725840-1-AP, 1:1000), mouse anti-mouse PKM2 (Proteintech, Cat. No. 60268-1-Ig, 1:1000), rabbit anti-mouse H3 (Proteintech, Cat. No. 17168-1-AP, 1:5000) and mouse anti-mouse β-actin (Proteintech, Cat. No. 66009-1-Ig, 1:5000).

Techniques: Activation Assay, Control, Expressing

Journal: Frontiers in Immunology

Article Title: GDF15 orchestrates mitochondrial-immune crosstalk via SMAD7-HIF-1α-PKM2 cascade to attenuate septic liver injury

doi: 10.3389/fimmu.2025.1712741

Figure Lengend Snippet: GDF15 correlates with clinical severity in sepsis. (A) Circulating GDF15 levels: Healthy controls (HC, n=91) vs. Sepsis patients (SP, n=119). (B–N) Correlation network of GDF15 with clinical parameters: WBC, CRP, SOFA, SAA, PCT, Glu, Lactate, PLT, SOFA, ALT, AST, TBIL, IL-6 and TNF-α (n=210). Solid lines represent linear regression fits for visual trend estimation, while r and P values are derived from Spearman’s rank correlation analysis.

Article Snippet: Proteins (30 μg/lane) were separated on 10% SDS-PAGE gels, transferred to PVDF membranes (Millipore, IPVH00010), and probed with the following primary antibodies: rabbit anti-mouse UQCRC1 (Proteintech, Cat. No. 21705-1-AP, 1:1000), rabbit anti-mouse GDF15 (Proteintech, Cat. No. 27455-1-AP, 1:1000), rabbit anti-mouse HIF-1α (Proteintech, Cat. No. 20960-1-AP, 1:1000), rabbit anti-mouse SMAD7 (Proteintech, Cat. No. 725840-1-AP, 1:1000), mouse anti-mouse PKM2 (Proteintech, Cat. No. 60268-1-Ig, 1:1000), rabbit anti-mouse H3 (Proteintech, Cat. No. 17168-1-AP, 1:5000) and mouse anti-mouse β-actin (Proteintech, Cat. No. 66009-1-Ig, 1:5000).

Techniques: Derivative Assay