recombinant dkk1  (R&D Systems)

Journal: Bioactive Materials

Article Title: Microenvironment-mediated stem cell fate in periodontal tissue remodeling and repair

doi: 10.1016/j.bioactmat.2025.12.025

Figure Lengend Snippet: Comparisons of physiological and periodontitis microenvironments. In physiological conditions, factors in the microenvironment that directly interact with the residing MSCs include the ECM, growth factors, hormones and neighboring cells such as immune cells, endothelial cells and other MSCs. A healthy, well-organized ECM supports the adhesion, proliferation and tissue-specific differentiation of MSCs. Growth factors such as TGF-β1, PDGF and FGF-2 foster MSC proliferation and fibrogenic differentiation, whereas IGF-1 facilitates osteogenesis. PTHrP/PPR signaling in DFSCs plays a critical role in root formation and tooth eruption. Macrophages, endothelial cells and MSCs in normal conditions all favor tissue-specific differentiation of MSCs, especially osteogenic differentiation in the periodontal context. In periodontitis conditions, bacterial invasion of the local microenvironment directly suppresses MSC osteogenic differentiation through PAMPs and virulence factors. Excessive ROS generation further impairs MSC osteogenesis, while hypoxia exerts context-dependent effects on MSC fate. In addition, MMP-mediated ECM degradation reduces matrix stiffness and compromises the osteogenic capacity of MSCs. The expression of proinflammatory cytokines in gingival crevicular fluid and periodontal tissues is increased, including IL-1 family members (IL-1β, IL-18, IL-33, IL-36β and IL-36γ), IL-6, TNFα, IL-17, IL-12 and IL-23. High levels of proinflammatory cytokines inhibit the osteogenic differentiation of MSCs and may further stimulate the secretion of proinflammatory cytokines. Meanwhile, inflamed macrophages secrete proinflammatory exosomes that hinder the osteogenic differentiation of MSCs. Notably, some inflamed MSCs can release immunomodulatory exosomes that promote M2 macrophage polarization to mitigate inflammation. Created with BioRender.com .

Article Snippet: Physiological microenvironment , PDLSCs , ECM , RhoA/ROCK signaling , Osteogenic differentiation↑ Collagen-I and fibronectin production↑ Cytoskeleton formation↑ , [ , , ] .

Techniques: Expressing

Journal: Bioactive Materials

Article Title: Microenvironment-mediated stem cell fate in periodontal tissue remodeling and repair

doi: 10.1016/j.bioactmat.2025.12.025

Figure Lengend Snippet: Interactions between the microenvironment and stem cells in periodontal injuries. In periodontal bone fracture, N2-neutrophils are initially recruited to injury sites and secrete SDF-1α to recruit BMSCs. The recruitment of BMSCs to injury sites enables further osteogenesis and matrix production, contributing to fracture healing. MSCs induce M2 polarization in macrophages, and M2 macrophages in turn facilitate osteogenic differentiation in BMSCs partly via exosomes. The increased expression of AMBN in the ECM during bone fracture promotes the osteogenic and chondrogenic differentiation of BMSCs. In gingival injuries, the influx of blood brings thrombin, PDGF-BB, TGF-β, LPA, proteases and chemokines into interstitial tissues, activating local fibroblasts to recruit immune cells via IL-8 secretion. Immune cells promote the activation of fibroblasts in a feedback loop, aggravating the local inflammatory response. PDGF-BB and TGF-β stimulate fibroblast proliferation, migration and ECM production. In response to PDGF, LPA and thrombin, migratory fibroblasts further differentiate into myofibroblasts, which are distributed along wound margins to facilitate wound contraction. Created with BioRender.com .

Article Snippet: Physiological microenvironment , PDLSCs , ECM , RhoA/ROCK signaling , Osteogenic differentiation↑ Collagen-I and fibronectin production↑ Cytoskeleton formation↑ , [ , , ] .

Techniques: Expressing, Activation Assay, Migration

Journal: Bioactive Materials

Article Title: Microenvironment-mediated stem cell fate in periodontal tissue remodeling and repair

doi: 10.1016/j.bioactmat.2025.12.025

Figure Lengend Snippet: Tackling the inflammatory microenvironment. Killing bacteria, immunoregulation and ROS clearance are effective strategies to control inflammation. The emergence of antibacterial nanoparticles, such as nMgO and nAg, as well as antibacterial polypeptides, helps overcome the practical limitations when antibiotics are incorporated into materials. The encapsulation and controlled release of immunoregulatory biomolecules is a strategy for immunoregulation. The controlled release of IL-2, TGF-β and miR-10a achieved by MSNs and PLGA MS facilitates the recruitment and differentiation of Tregs. Metal elements and nanomaterials provide alternative solutions. Mo, AuNPs and some polypeptides induce M2 macrophage polarization. When combined with quercetin, the nano-octahedral ceria-based composite inhibits M1 polarization, facilitates M2 polarization, downregulates proinflammatory cytokines and upregulates anti-inflammatory cytokines. Building an ROS clearing platform with ROS scavengers such as PDA, NAC, CoO, Prussian blue (PB) and Mn not only protects stem cells from oxidative damage but also alleviates inflammation and enhances bone formation. Created with BioRender.com .

Article Snippet: Physiological microenvironment , PDLSCs , ECM , RhoA/ROCK signaling , Osteogenic differentiation↑ Collagen-I and fibronectin production↑ Cytoskeleton formation↑ , [ , , ] .

Techniques: Bacteria, Control, Encapsulation

Journal: Bioactive Materials

Article Title: Microenvironment-mediated stem cell fate in periodontal tissue remodeling and repair

doi: 10.1016/j.bioactmat.2025.12.025

Figure Lengend Snippet: Schematic illustration of stem cell interactions with various biomaterials in periodontal regeneration. Biomaterials closely interact with stem cells to support periodontal regeneration. MSC-laden mineralized hydrogels mimic the cellular, structural, and chemical features of bone autografts, activating RhoA/ROCK signaling, inducing YAP nuclear translocation, and upregulating RUNX2 expression in encapsulated MSCs. Phosphate ions in the mineralization medium and matrix further enhance ATP and adenosine production, with adenosine binding to A2b receptors to drive osteogenesis . GTR/GBR membranes facilitate adhesion, proliferation, and osteogenic differentiation of recruited stem cells through bioactive components such as PDA, AMP, β-TCP, and CeO2 NPs [ , , , ]. Various scaffold systems also contribute to regeneration. A tetra-PEG network incorporating chitosan enables sustained release of ASA, which promotes bone formation via T-cell suppression and enhances PDLSC osteogenesis while inducing M2 macrophage polarization through upregulated MCP-1 secretion . Electroactive mineralized scaffolds activate voltage-gated Ca 2+ channels and ATP-mediated cytoskeletal remodeling, promoting MSC osteogenesis through the BMP2/Smad5 pathway . A tissue-specific scaffold combining aligned MEW PCL fibers with F/CaP-coated fibers supports ligamentogenic and osteogenic differentiation of PDLSCs . Furthermore, materials engineered with specific mechanobiological features, such as anisotropic surface potential, magnetism, viscoelasticity, and optimized elastic modulus, enhance MSC osteogenic differentiation via mechanotransduction pathways [ , , ]. Created with BioRender.com .

Article Snippet: Physiological microenvironment , PDLSCs , ECM , RhoA/ROCK signaling , Osteogenic differentiation↑ Collagen-I and fibronectin production↑ Cytoskeleton formation↑ , [ , , ] .

Techniques: Translocation Assay, Expressing, Binding Assay

Journal: iScience

Article Title: Platelet DKK1 promotes tolerogenic dendritic cells and non-healing responses in cutaneous leishmaniasis

doi: 10.1016/j.isci.2026.115090

Figure Lengend Snippet: Decreased MPO + , CD11b + , and MHC class II + neutrophils in MyD88 (PKO) - and DKK1 (PKO) -infected mice (A–G) Six-week-old female WT-BALB/c, MyD88 (PKO) and DKK1 (PKO) mice were challenged with infective metacyclic promastigote (2 ×10 6 parasites, n = 5 per group) of L . major via the footpad. Non-infected BALB/c mice ( n = 10/2 feet per mouse) were given 0.9% NaCl saline. Cells were isolated from the footpads of all infected and non-infected mice at days 3 and 14 PI. Samples were analyzed by flow cytometry for MPO + , CD11b + , and MHC class II + neutrophils. A representative flow cytometry dot plot of MPO + , CD11b + , and MHC class II + neutrophils on day 3 is presented in . The percentage of MPO + , CD11b + , and MHC class II + cells in the different experimental groups is shown in column graphs (A, B, C, D, E, and F), while the absolute number of neutrophils obtained on day 3 PI is indicated (G). In all experiments, infected and non-infected BALB/c mice served as positive and negative controls, respectively. Results are presented as mean (±SEM) and are representative of two independent experiments. One-way ANOVA followed by Bonferroni’s post hoc test was used to analyze the data ∗ p < 0.05; ∗∗ p < 0.01; ∗∗∗ p < 0.001; ns, non-significant ( p > 0.05).

Article Snippet: Rested immature dendritic cells were stimulated with 100 ng/mL of recombinant DKK1 (R & D Systems), 20 ng/mL of recombinant IL-10 (Thermo Fisher Scientific), or 10 ng/mL of recombinant TNF-α (Thermo Fisher Scientific).

Techniques: Infection, Saline, Isolation, Flow Cytometry

Journal: iScience

Article Title: Platelet DKK1 promotes tolerogenic dendritic cells and non-healing responses in cutaneous leishmaniasis

doi: 10.1016/j.isci.2026.115090

Figure Lengend Snippet: Increased CD38 + macrophages and CD8α + dendritic cells in MyD88 (PKO) - and DKK1 (PKO) -infected mice (A–D) Six-week-old female WT-BALB/c, MyD88 (PKO) and DKK1 (PKO) mice were challenged with infective metacyclic promastigote (2 ×10 6 parasites, n = 5 per group) of L . major via the footpad. One week and two weeks post-infection, cells from the infected foot of each mouse in BALB/c, MyD88 (PKO) , DKK1 (PKO) , and non-infected BALB/c mice ( n = 10/2 feet per mouse) were harvested and counted for macrophages (A and B) and dendritic cells (C and D) by flow cytometry. (E–H) Two weeks post-infection, the infected foot from each mouse in BALB/c, MyD88 (PKO) , DKK1 (PKO) ( n = 5 per group), and non-infected BALB/c mice ( n = 10/2 feet per mouse) were examined for CD206 + and CD38 + macrophages (E and F), as well as CD11b + and CD8α + dendritic cells (G and H) by flow cytometry. Representative flow cytometry dot plots showing the analysis of CD206 + , CD38 + macrophages and CD11b + , CD8α + dendritic cells and a dot plot of each sample in all the experimental groups performed on day 14 PI are presented in . Results are presented as mean ± SEM and are representative of two independent experiments. Data analysis was done using one-way ANOVA followed by Bonferroni’s post hoc test ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, and “ns” indicates non-significant.

Article Snippet: Rested immature dendritic cells were stimulated with 100 ng/mL of recombinant DKK1 (R & D Systems), 20 ng/mL of recombinant IL-10 (Thermo Fisher Scientific), or 10 ng/mL of recombinant TNF-α (Thermo Fisher Scientific).

Techniques: Infection, Flow Cytometry

Journal: iScience

Article Title: Platelet DKK1 promotes tolerogenic dendritic cells and non-healing responses in cutaneous leishmaniasis

doi: 10.1016/j.isci.2026.115090

Figure Lengend Snippet: DKK1 promotes IL-10 induction in BALB/c-infected mice (A–F) Six-week-old female BALB/c, MyD88 (PKO) and DKK1 (PKO) mice were challenged with infective metacyclic promastigote (2 ×10 6 parasites, n = 5 per group) of L . major via the footpad. Non-infected BALB/c mice ( n = 5) were given 0.9% NaCl saline. Two or fifteen weeks post-infection, cells from draining lymph nodes were isolated. Lymph node cells were incubated with SLAG (50 μg/mL derived from WT parasites). Cell culture supernatant samples obtained were analyzed by ELISA for cytokine production, as shown in the column graphs (A–F). In all the experiments, BALB/c infected and non-infected mice served as positive and negative controls, respectively. Results are presented as mean ± SEM and are representative of two independent experiments. One-way ANOVA followed by Bonferroni’s post hoc test was used to analyze the data ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, “ns” indicates not significant ( p > 0.05).

Article Snippet: Rested immature dendritic cells were stimulated with 100 ng/mL of recombinant DKK1 (R & D Systems), 20 ng/mL of recombinant IL-10 (Thermo Fisher Scientific), or 10 ng/mL of recombinant TNF-α (Thermo Fisher Scientific).

Techniques: Infection, Saline, Isolation, Incubation, Derivative Assay, Cell Culture, Enzyme-linked Immunosorbent Assay

Journal: iScience

Article Title: Platelet DKK1 promotes tolerogenic dendritic cells and non-healing responses in cutaneous leishmaniasis

doi: 10.1016/j.isci.2026.115090

Figure Lengend Snippet: Impaired CD8 + IL-10 + IFN-γ − , CD4 + IL-10 + IFN-γ − , and CD4 + IL-10 + IFNg + T cells in MyD88 (PKO) - and DKK1 (PKO) -infected mice on day 14 PI (A–M) Six-week-old female BALB/c, MyD88 (PKO) , and DKK1 (PKO) mice were challenged with infective metacyclic promastigote (2 ×10 6 parasites, n = 5 per group) of L . major via the footpad. Non-infected BALB/c mice ( n = 5) were given 0.9% NaCl saline. Two weeks post-infection, the draining and non-draining lymph node cells were isolated. Lymph node cells were incubated with a cell stimulation cocktail for 5 h. After a further 3 h in BFA, cells were stained for intracellular IL-10 and IFN-γ. The stained lymph node cells from each mouse in BALB/c, MyD88 (PKO) - and DKK1 (PKO) -infected mice were determined for the percentage and frequency of CD4 + and CD8 + T cells (A, B, C, and B), percentage and MFI of CD8 + IFN-γ + or CD8 + IL-10 + T cells (E, F, G, and H), percentage and MFI of CD4 + IFN-γ + or CD4 + IL-10 + T cells (I, J, K, and L), and percentage of CD4 + IFN-γ + IL-10 + T cells (M) by flow cytometry. Representative flow cytometry dot plots showing the analyses CD4 + and CD8 + T cells, CD8 + IFN-γ + or CD8 + IL-10 + T cells, CD4 + IFN-γ + or CD4 + IL-10 + T cells, and CD4 + IFN-γ + IL-10 + T cells performed on day 14 PI is indicated ( A). Results are presented as mean ± SEM. and are representative of triplicate experiments. Data analysis was done using one-way ANOVA followed by Bonferroni’s post hoc test ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, and “ns” indicates non-significant.

Article Snippet: Rested immature dendritic cells were stimulated with 100 ng/mL of recombinant DKK1 (R & D Systems), 20 ng/mL of recombinant IL-10 (Thermo Fisher Scientific), or 10 ng/mL of recombinant TNF-α (Thermo Fisher Scientific).

Techniques: Infection, Saline, Isolation, Incubation, Cell Stimulation, Staining, Flow Cytometry

Journal: iScience

Article Title: Platelet DKK1 promotes tolerogenic dendritic cells and non-healing responses in cutaneous leishmaniasis

doi: 10.1016/j.isci.2026.115090

Figure Lengend Snippet: Minimal expression and percentage of MHC II + , CD86 + , and CD80 + dendritic cells in the presence of recombinant DKK1 (A) Monocyte-derived dendritic cells were incubated in rDKK1(100 ng/mL), rIL-10 (20 ng/mL) and rTNF-α (10 ng/mL). Cells harvested at 24 and 48 h post-incubation were used to determine the expression and percentage of MHC II + , CD86 + , and CD80 + cells by flow cytometry. Representative flow cytometry dot plots generated 24 h post-incubation showed the analysis of MHC II + , CD86 + and CD80 + as indicated (A). (B–G) The percentage (B, D, and F) and MFI (C, E, and G) of MHC II + , CD86 + and CD80 + in the different experimental conditions are shown in the bar graphs. Results are presented as mean (±SEM) and are representative of triplicate experiments. One-way ANOVA followed by Bonferroni’s post hoc test was used to analyze the data (∗ p < 0.05, ∗∗ p < 0.01; ∗∗∗ p < 0.001; and “ns” indicates non-significant.

Article Snippet: Rested immature dendritic cells were stimulated with 100 ng/mL of recombinant DKK1 (R & D Systems), 20 ng/mL of recombinant IL-10 (Thermo Fisher Scientific), or 10 ng/mL of recombinant TNF-α (Thermo Fisher Scientific).

Techniques: Expressing, Recombinant, Derivative Assay, Incubation, Flow Cytometry, Generated

Journal: iScience

Article Title: Platelet DKK1 promotes tolerogenic dendritic cells and non-healing responses in cutaneous leishmaniasis

doi: 10.1016/j.isci.2026.115090

Figure Lengend Snippet: r-DKK1 blocked TNF-α-induced MHC II + and CD86 + expression of dendritic cells (A) Monocyte-derived dendritic cells were incubated in rDKK1(100 ng/mL), rTNF-α (10 ng/mL), and (rDKK1 + rTNF-α). Cells harvested at 48 h post-incubation were used to determine the percentage of MHC II + and CD86 + cells by flow cytometry. Representative flow cytometry dot plots generated 48 h post-incubation showed the analysis of MHC II + and CD86 + as indicated (A). (B and C) The percentage (B and C) of MHC II + and CD86 + in the different experimental conditions are shown in the bar graphs. Results are presented as mean (±SEM) and are representative of triplicate experiments. One-way ANOVA followed by Bonferroni’s post hoc test was used to analyze the data (∗ p < 0.05, ∗∗ p < 0.01; and “ns” indicates non-significant.

Article Snippet: Rested immature dendritic cells were stimulated with 100 ng/mL of recombinant DKK1 (R & D Systems), 20 ng/mL of recombinant IL-10 (Thermo Fisher Scientific), or 10 ng/mL of recombinant TNF-α (Thermo Fisher Scientific).

Techniques: Expressing, Derivative Assay, Incubation, Flow Cytometry, Generated

Journal: iScience

Article Title: Platelet DKK1 promotes tolerogenic dendritic cells and non-healing responses in cutaneous leishmaniasis

doi: 10.1016/j.isci.2026.115090

Figure Lengend Snippet: Elevated IL-10 and reduced IL-12 production in rDKK1-treated dendritic cells (A and B) Monocyte-derived dendritic cells were incubated in r-DKK1(100 ng/mL), r-IL-10 (20 ng/mL), r-TNF-α (10 ng/mL) or r-TNF-α + r-DKK1. Cell culture supernatants harvested 24 and 48 h post-incubation were used to determine IL-10 and IL-12 production by ELISA, as shown in the bar graphs (A and B). Results are presented as mean ± SEM and are representative of triplicate experiments. One-way ANOVA followed by Bonferroni’s post hoc test was used to analyze the data (∗ p < 0.05, ∗∗ p < 0.01). “ns” indicates not significant.

Article Snippet: Rested immature dendritic cells were stimulated with 100 ng/mL of recombinant DKK1 (R & D Systems), 20 ng/mL of recombinant IL-10 (Thermo Fisher Scientific), or 10 ng/mL of recombinant TNF-α (Thermo Fisher Scientific).

Techniques: Derivative Assay, Incubation, Cell Culture, Enzyme-linked Immunosorbent Assay

Journal: iScience

Article Title: Platelet DKK1 promotes tolerogenic dendritic cells and non-healing responses in cutaneous leishmaniasis

doi: 10.1016/j.isci.2026.115090

Figure Lengend Snippet: rDKK1-treated dendritic cells significantly increased the percentage of IL-10-producing CD4 T cells (A and B) Rested immature dendritic cells were stimulated with 100 ng/mL of recombinant DKK1 or 10 ng/mL of recombinant TNF-α for 24 h. The rDKK1 and r-TNF-α-treated dendritic cells were incubated for 4 h in a 24-well plate (2 × 10 5 per well) in 200 μL of medium in the presence of SLAG (100 ng/ml). SLAG-loaded rDKK1 and r-TNF-α-treated dendritic cells (2 ×10 5 ) were then washed and co-cultured with infected WT-BALB/c lymph node T cells (1 ×10 6 ) in complete RPMI 1640 medium in a 1:5 ratio for 72 h. The cells were surface-stained with appropriate antibodies before intracellular IL-10 staining with a cell stimulation cocktail and BD Golgi plug. The stained lymph node cells from the experimental condition were determined for the percentage of CD4 + IL-10 + T cells by flow cytometry. Representative flow cytometry dot plots showed the analysis of CD4 + IL-10 + T cells (A). The percentage of CD4 + IL-10 + T cells in the different experimental conditions is indicated (B). The non-treated and r-TNF-α-treated dendritic cells serve as controls. Results are presented as mean ± SEM and are representative of three replicate experiments. One-way ANOVA followed by Bonferroni’s post hoc test was used to analyze the data ∗∗∗ p < 0.001; ns indicates not significant ( p > 0.05).

Article Snippet: Rested immature dendritic cells were stimulated with 100 ng/mL of recombinant DKK1 (R & D Systems), 20 ng/mL of recombinant IL-10 (Thermo Fisher Scientific), or 10 ng/mL of recombinant TNF-α (Thermo Fisher Scientific).

Techniques: Recombinant, Incubation, Cell Culture, Infection, Staining, Cell Stimulation, Flow Cytometry

Journal: iScience

Article Title: Platelet DKK1 promotes tolerogenic dendritic cells and non-healing responses in cutaneous leishmaniasis

doi: 10.1016/j.isci.2026.115090

Figure Lengend Snippet: Lesion size and parasite burden decreased in MyD88 (PKO) - and DKK1 (PKO) -infected mice (A–C) Six-week-old female WT-BALB/c, MyD88 (PKO) and DKK1 (PKO) mice were challenged with infective metacyclic promastigote (2 ×10 6 parasites) of L . major via the footpad. The infected foot from each mouse in BALB/c, MyD88 (PKO) - and DKK1 (PKO) -infected mice ( n = 5 per group) were measured for lesion size weekly using a vernier caliper (A), and parasite burden (at day week 6 and 15PI) was determined by limiting dilution assay (B and C). Results are presented as mean ± SEM. For Figure (A), mice in each infected group were compared with the non-infected group and data analysis was done using one-way ANOVA followed by Bonferroni’s post hoc test ∗ p < 0.05; ∗∗ p < 0.01, ∗∗∗ p < 0.001.

Article Snippet: Rested immature dendritic cells were stimulated with 100 ng/mL of recombinant DKK1 (R & D Systems), 20 ng/mL of recombinant IL-10 (Thermo Fisher Scientific), or 10 ng/mL of recombinant TNF-α (Thermo Fisher Scientific).

Techniques: Infection, Limiting Dilution Assay