Journal: Signal Transduction and Targeted Therapy

Article Title: Piezo1 activation suppresses bone marrow adipogenesis to prevent osteoporosis by inhibiting a mechanoinflammatory autocrine loop

doi: 10.1038/s41392-025-02455-w

Figure Lengend Snippet: Piezo1 suppresses Lcn2 expression and secretion via the inhibition of Ccl2-evoked NF-κB activation. BMMSCs were isolated from femurs and tibias of 10-week-old male PDGFRα-Piezo1 KO mice and WT controls. a Gene expression of Ccr2 in BMMSCs, as determined by real-time PCR. b–g Recombinant mouse Ccl2 protein (rmCcl2, 100 ng/mL) or the CCR2 antagonist INCB3344 (10 nM) was added to the adipogenic and osteogenic induction medium during BMMSC differentiation. The expression levels of osteogenic genes ( b–d ) and adipogenic genes ( e–g ) were determined via real-time qPCR. h–n WT and KO BMMSCs were treated with rmCcl2 (100 ng/mL) or the CCR2 antagonist INCB3344 (10 nM) for 24 h. h Sonicated BMMSCs were subjected to chromatin immunoprecipitation (ChIP) using an anti-p65 antibody. The ChIP DNA samples were then subjected to qPCR amplification using specific primers against the promoter region of Lcn2, as shown in supplementary Fig. . Representative gel images of end-point ChIP-qPCR products are shown. i Quantitative results are shown as the percentage of input DNA: % of Input = 2^(CT Input −CT IP )/dilution factor × 100%. j Luciferase reporter assay was performed in isolated WT and KO BMMSCs transfected with pGL3 constructs containing the mouse wild-type Lcn2 promoter (Lcn2-WT) or the mutated Lcn2 promoter with mutations in the NF-κB binding motif (Lcn2-Mut, sequence in supplementary Fig. ). The firefly luciferase activity was measured and normalized to Renilla luciferase activity. k Schematic diagram illustrating the actions of rmCcl2, the CCR2 antagonist, and the NF-κB-specific inhibitor QNZ on NF-κB translocation and Lcn2 expression; created with BioRender ( https://BioRender.com ). l ELISA analysis of total p65 in the nucleus and cytoplasm of BMMSCs. m Representative immunofluorescence images of intracellular p65 localization. Nuclei were stained with DAPI (blue). Scale bar, 50 μm. n P65 nuclear translocation was quantified by ImageJ software via Pearson’s correlation coefficient (PCC) between the p65 immunofluorescence signal and DAPI staining across segmented nuclear regions. o , p WT and KO BMMSCs were treated with the NF-κB-specific inhibitor QNZ (10 nM) for another 2 h after 24-h treatment of rmCcl2 (100 ng/mL) and INCB3344 (10 nM). o The mRNA level of Lcn2 . p Lcn2 levels in the culture medium were determined by ELISA. q Illustration of how the AP-1 inhibitor modulates Ccl2 gene expression; created with BioRender ( https://BioRender.com ). r–u WT and KO BMMSCs were treated with the AP-1-specific inhibitor T-5224 (10 μM) for 24 h. r Sonicated BMMSCs were subjected to ChIP assay using an anti-c-Jun antibody. Representative gel images of end-point ChIP-qPCR products are shown. s Quantitative results are shown as the percentage of input DNA. t The mRNA level of Ccl2 . u Ccl2 levels in the culture medium were determined by ELISA. v Luciferase reporter assay was performed in isolated WT and KO BMMSCs transfected with pGL3 constructs containing the mouse wild-type Ccl2 promoter (Ccl2-WT) or the mutated Ccl2 promoter with mutations in the c-Jun binding motif (Ccl2-Mut, sequence in supplementary Fig. ). The firefly luciferase activity was measured and normalized to Renilla luciferase activity. n = 5 for each group. The data are presented as the means ± SEMs; * p < 0.05, ** p < 0.01, *** p < 0.001. See also supplementary Figs. –

Article Snippet: The luciferase reporter assay was performed by transfecting 0.2 μg of firefly and Renilla luciferase reporter vectors (Addgene, #128046) driven by either the wild-type mouse Lcn2 or Ccl2 promoter (−1999/+1) or their respective mutants (in which the NF-κB or c-Jun DNA binding site was mutated) (Azenta) into BMMSCs seeded in 96-well plates using Lipofectamine 3000 transfection reagent (Thermo Fisher Scientific, #L3000001).

Techniques: Expressing, Inhibition, Activation Assay, Isolation, Gene Expression, Real-time Polymerase Chain Reaction, Recombinant, Sonication, Chromatin Immunoprecipitation, Amplification, ChIP-qPCR, Luciferase, Reporter Assay, Transfection, Construct, Binding Assay, Sequencing, Activity Assay, Translocation Assay, Enzyme-linked Immunosorbent Assay, Immunofluorescence, Staining, Software

Journal: International journal of molecular sciences

Article Title: Hepatocyte Nuclear Factor 4α (HNF4α) Plays a Controlling Role in Expression of the Retinoic Acid Receptor β ( RARβ ) Gene in Hepatocytes.

doi: 10.3390/ijms24108608

Figure Lengend Snippet: Figure 2. HNF4α regulates the promoter of the RARβ gene in HepG2 cells. HepG2 cells in 24-well plates were co-transfected for 24 h with a fragment of the human RARβ promoter expanding from −1.7 kbp from transcription start site to +0.217 kpb, as the full length promoter construct, in pGL3- basic-luc vector together with pRLTK plasmid containing Renilla-luc, as the control, and with either human HNF4α, RARα/RXRα, or all three transcription factors, and then treated further either without (A) or with RA for 1 to 24 h, after which the cells were collected to assay for luciferase activity. HNF4α alone or with RARα/RXRα suppressed the promoter activity of the human RARβ gene in the cells treated without RA (A), but upregulated the promoter when the cells were treated with RA following transfection (B). HNF4α regulates the promoter of the mouse RARβ gene in HepG2 cells (C). It suppresses the promoter activity of the mouse gene (empty bars in C) in HepG2 cells treated with the vehicle, but it increases the promoter activity in the cells treated with RA (black bar in C).

Article Snippet: Construction of the plasmid vectors including pGL3-Basic-hCYP26A1-E4-luc (submitted to addgene.org), pGL3-Basic-hRARβp-luc (human RARβ2 promoter), pGL3-BasichCYP2C9p-luc, pcDNNA3.1-hRARα.hRXRα (submitted to addgene.org), and pcDNA3.1hHNF4α were reported previously [18,20,33,34,43].

Techniques: Transfection, Construct, Plasmid Preparation, Control, Luciferase, Activity Assay

Journal: International journal of molecular sciences

Article Title: Hepatocyte Nuclear Factor 4α (HNF4α) Plays a Controlling Role in Expression of the Retinoic Acid Receptor β ( RARβ ) Gene in Hepatocytes.

doi: 10.3390/ijms24108608

Figure Lengend Snippet: Figure 6. Mutation of the critical residues present in the ligand binding domain of human HNF4α suppresses transcription activation of the promoters of human APOC3 and CYP2C9 genes. HepG2 cells were co-transfected with either the pGL3-b-hApoC3 (A–C) or pGL3-b-hCYP2C9 (D–F) promoter construct together with either hHNF4α, RARα/RXRα, or all three transcription factors, and then treated with either vehicle or 1 µM RA for 24 h, after which the cells were assayed for their luciferase activity. The effects of the individual mutant residues in the ligand binding domain of the human HNF4α compared with WT HNF4α on the promoter activity of APOC3 (B) or CYP2C9 (E) in HepG2 cells treated with either vehicle or 1 µM RA for 24 h. The endogenous HNF4α transcriptional activity toward APOC3 (C) and CYP2C9 (F) promoters was assessed in HepG2 cells with or without the addition of human HNF4α mutants. Data from each bar represent the mean of n = 3 wells ± SD. HNF4α mutant #’s are as follows: (1) S190K, (2) 191MK, (3) R221G, (4) L228K, (5) L229K, (6) R235G, (7) I347K, and (8) I355K.

Article Snippet: Construction of the plasmid vectors including pGL3-Basic-hCYP26A1-E4-luc (submitted to addgene.org), pGL3-Basic-hRARβp-luc (human RARβ2 promoter), pGL3-BasichCYP2C9p-luc, pcDNNA3.1-hRARα.hRXRα (submitted to addgene.org), and pcDNA3.1hHNF4α were reported previously [18,20,33,34,43].

Techniques: Mutagenesis, Ligand Binding Assay, Activation Assay, Transfection, Construct, Luciferase, Activity Assay

Journal: International journal of molecular sciences

Article Title: Hepatocyte Nuclear Factor 4α (HNF4α) Plays a Controlling Role in Expression of the Retinoic Acid Receptor β ( RARβ ) Gene in Hepatocytes.

doi: 10.3390/ijms24108608

Figure Lengend Snippet: Figure 7. Mutation of the critical amino acid residues present in the ligand binding domain of human HNF4α suppresses transcription activation of the promoters of human CYP26A1 and RARβ genes in HepG2 cells treated with RA. HepG2 cells grown in 24-well plates were co-transfected with either pGL3-b-hCYP26A1 (A) or pGL3-b-hRARβ (B) promoters, each with pRLTK as the control, together with either wildtype (WT) HNF4α or its individual mutants (Mutant # 1 to 8), and then treated with either vehicle or 1 µM RA for 24 h, after which the cells were assayed for luciferase activity. Data from each bar represent the mean of n = 3 wells ± SD. HNF4α mutant #’s are as follows: (1) S190K, (2) 191MK, (3) R221G, (4) L228K, (5) L229K, (6) R235G, (7) I347K, and (8) I355K.

Article Snippet: Construction of the plasmid vectors including pGL3-Basic-hCYP26A1-E4-luc (submitted to addgene.org), pGL3-Basic-hRARβp-luc (human RARβ2 promoter), pGL3-BasichCYP2C9p-luc, pcDNNA3.1-hRARα.hRXRα (submitted to addgene.org), and pcDNA3.1hHNF4α were reported previously [18,20,33,34,43].

Techniques: Mutagenesis, Ligand Binding Assay, Activation Assay, Transfection, Control, Luciferase, Activity Assay

Journal: International Journal of Molecular Sciences

Article Title: Hepatocyte Nuclear Factor 4α (HNF4α) Plays a Controlling Role in Expression of the Retinoic Acid Receptor β ( RARβ ) Gene in Hepatocytes

doi: 10.3390/ijms24108608

Figure Lengend Snippet: HNF4α regulates the promoter of the RARβ gene in HepG2 cells. HepG2 cells in 24-well plates were co-transfected for 24 h with a fragment of the human RARβ promoter expanding from −1.7 kbp from transcription start site to +0.217 kpb, as the full length promoter construct, in p GL3-basic-luc vector together with p RLTK plasmid containing Renilla-luc, as the control, and with either human HNF4α, RARα/RXRα, or all three transcription factors, and then treated further either without ( A ) or with RA for 1 to 24 h, after which the cells were collected to assay for luciferase activity. HNF4α alone or with RARα/RXRα suppressed the promoter activity of the human RARβ gene in the cells treated without RA ( A ), but upregulated the promoter when the cells were treated with RA following transfection ( B ). HNF4α regulates the promoter of the mouse RARβ gene in HepG2 cells ( C ). It suppresses the promoter activity of the mouse gene (empty bars in C) in HepG2 cells treated with the vehicle, but it increases the promoter activity in the cells treated with RA (black bar in C).

Article Snippet: Construction of the plasmid vectors including p GL3-Basic-hCYP26A1-E4-luc (submitted to addgene.org), p GL3-Basic-hRARβp-luc (human RARβ2 promoter), p GL3-Basic-hCYP2C9p-luc, p cDNNA3.1-hRARα.hRXRα (submitted to addgene.org), and p cDNA3.1-hHNF4α were reported previously [ , , , , ].

Techniques: Transfection, Construct, Plasmid Preparation, Control, Luciferase, Activity Assay

Journal: International Journal of Molecular Sciences

Article Title: Hepatocyte Nuclear Factor 4α (HNF4α) Plays a Controlling Role in Expression of the Retinoic Acid Receptor β ( RARβ ) Gene in Hepatocytes

doi: 10.3390/ijms24108608

Figure Lengend Snippet: Mutation of the critical residues present in the ligand binding domain of human HNF4α suppresses transcription activation of the promoters of human APOC3 and CYP2C9 genes. HepG2 cells were co-transfected with either the p GL3-b-hApoC3 ( A – C ) or p GL3-b-hCYP2C9 ( D – F ) promoter construct together with either hHNF4α, RARα/RXRα, or all three transcription factors, and then treated with either vehicle or 1 µM RA for 24 h, after which the cells were assayed for their luciferase activity. The effects of the individual mutant residues in the ligand binding domain of the human HNF4α compared with WT HNF4α on the promoter activity of APOC3 ( B ) or CYP2C9 ( E ) in HepG2 cells treated with either vehicle or 1 μM RA for 24 h. The endogenous HNF4α transcriptional activity toward APOC3 ( C ) and CYP2C9 ( F ) promoters was assessed in HepG2 cells with or without the addition of human HNF4α mutants. Data from each bar represent the mean of n = 3 wells ± SD. HNF4α mutant #’s are as follows: (1) S190K, (2) 191MK, (3) R221G, (4) L228K, (5) L229K, (6) R235G, (7) I347K, and (8) I355K.

Article Snippet: Construction of the plasmid vectors including p GL3-Basic-hCYP26A1-E4-luc (submitted to addgene.org), p GL3-Basic-hRARβp-luc (human RARβ2 promoter), p GL3-Basic-hCYP2C9p-luc, p cDNNA3.1-hRARα.hRXRα (submitted to addgene.org), and p cDNA3.1-hHNF4α were reported previously [ , , , , ].

Techniques: Mutagenesis, Ligand Binding Assay, Activation Assay, Transfection, Construct, Luciferase, Activity Assay

Journal: International Journal of Molecular Sciences

Article Title: Hepatocyte Nuclear Factor 4α (HNF4α) Plays a Controlling Role in Expression of the Retinoic Acid Receptor β ( RARβ ) Gene in Hepatocytes

doi: 10.3390/ijms24108608

Figure Lengend Snippet: Mutation of the critical amino acid residues present in the ligand binding domain of human HNF4α suppresses transcription activation of the promoters of human CYP26A1 and RARβ genes in HepG2 cells treated with RA. HepG2 cells grown in 24-well plates were co-transfected with either p GL3-b-hCYP26A1 ( A ) or p GL3-b-hRARβ ( B ) promoters, each with p RLTK as the control, together with either wildtype (WT) HNF4α or its individual mutants (Mutant # 1 to 8), and then treated with either vehicle or 1 µM RA for 24 h, after which the cells were assayed for luciferase activity. Data from each bar represent the mean of n = 3 wells ± SD. HNF4α mutant #’s are as follows: (1) S190K, (2) 191MK, (3) R221G, (4) L228K, (5) L229K, (6) R235G, (7) I347K, and (8) I355K.

Article Snippet: Construction of the plasmid vectors including p GL3-Basic-hCYP26A1-E4-luc (submitted to addgene.org), p GL3-Basic-hRARβp-luc (human RARβ2 promoter), p GL3-Basic-hCYP2C9p-luc, p cDNNA3.1-hRARα.hRXRα (submitted to addgene.org), and p cDNA3.1-hHNF4α were reported previously [ , , , , ].

Techniques: Mutagenesis, Ligand Binding Assay, Activation Assay, Transfection, Control, Luciferase, Activity Assay