saa2 recombinant protein  (MedChemExpress)

Journal: bioRxiv

Article Title: Borrelia Burgdorferi binds Serum Amyloid A and Modulates Subcutaneous Adipose Tissue Immune Signaling

doi: 10.64898/2026.01.29.702514

Figure Lengend Snippet: Single Cell RNA Sequencing (scRNA seq) (10X Genomics) of 31,953 adipose tissue stromal vascular fraction (SVF) cells (13,023 from Bb-infected tissue, 18,930 from uninfected tissue) (n=3 Uninfected control, n=2 Bb- infected tissue specimens). (A) Uniform Manifold Approximation and Projection (UMAP) plots indicate 7 unique cell types with a total of 10 clusters. (B) Bubble plot shows adipose stem/progenitor cells and monocyte/macrophage (Mono/Mø) clusters and their expressed immune focused pathways from MSigDB Hallmark gene sets. (C) Total SAA (SAA1+SAA2) gene expression across tissue cohorts. (D) SAA-related genes expressed per cluster showing average expression across cell type and percent of cells expressing each gene of interest. Genes upregulated during infection were plotted in red and genes downregulated after infection plotted in blue. The size of the bubble is based on the percentage of cells within that cell type cluster expression each gene. (E) Total SAA gene expression (SAA1+SAA2) across cell clusters within each tissue cohort. Abbreviations: ASPC: adipose stem/progenitor cells; LEC: lymphatic endothelial cells; Mono/Mø: monocytes/macrophages; SMC: smooth muscle cells.

Article Snippet: Spirochetes were pelleted at 5000 x g for 5 minutes, washed with 1x PBS, then resuspended in solution with SAA2 recombinant protein (hSAA2-His: MedChemExpress HY-P70985, Elabscience PKSH033532; mSAA2-His: antibodies online ABIN7088660) at 1μg/mL, 10μg/mL or 40μg/mL for 1h at room temperature.

Techniques: Single Cell, RNA Sequencing, Infection, Control, Gene Expression, Expressing

Journal: bioRxiv

Article Title: Borrelia Burgdorferi binds Serum Amyloid A and Modulates Subcutaneous Adipose Tissue Immune Signaling

doi: 10.64898/2026.01.29.702514

Figure Lengend Snippet: SAA2-bound spirochetes were stained for the presence of attached His-tagged protein (SAA2) detected by flow cytometry using an anti-His-tag fluorescent (PE/Cy5) conjugated antibody. (A) Histogram plots showing human SAA (hSAA2 and hSAA1), relative to non-stained controls (grey) and positive control protein (brown) known to bind Borrelia (Peptidoglycan Recognition Protein 1 (PGLYRP1) – Ref 39). The dashed line represents 40 µg/mL of hSAA2. The solid line represents 10µg/mL hSAA2. (B) Streptococcus pneumoniae incubated with 40µg/mL recombinant hSAA2 showing no increase in fluorescence compared to control. (C) Repeat binding assays showing histograms representing SAA2 binding multiple isolates of Bb sensu stricto (B31, CA8, HP19, CT-1, NT-1).

Article Snippet: Spirochetes were pelleted at 5000 x g for 5 minutes, washed with 1x PBS, then resuspended in solution with SAA2 recombinant protein (hSAA2-His: MedChemExpress HY-P70985, Elabscience PKSH033532; mSAA2-His: antibodies online ABIN7088660) at 1μg/mL, 10μg/mL or 40μg/mL for 1h at room temperature.

Techniques: Staining, Flow Cytometry, Positive Control, Incubation, Recombinant, Fluorescence, Control, Binding Assay

Journal: bioRxiv

Article Title: Borrelia Burgdorferi binds Serum Amyloid A and Modulates Subcutaneous Adipose Tissue Immune Signaling

doi: 10.64898/2026.01.29.702514

Figure Lengend Snippet: (A) Experimental workflow diagram of flow cytometry binding assay. Spirochetes cultured at 37°C for 24h were allowed to bind recombinant His-tagged mSAA2. Anti-His tag fluorescent (PE/Cy5) primary conjugated antibodies were bound to SAA-spirochete complexes to label protein attached to spirochetes. Spirochetes were washed and used for flow cytometry analysis compared to unstained spirochete complexes. (B) Histogram plots indicating murine SAA2 (mSAA2) binds SAA2 relative to staining control ( Bb + mSAA2) and positive control protein peptidoglycan recognition protein-1 (PGLYRP1 ref 39). (C) Binding of mSAA2 to Bb sensu stricto strains B31, CA8, HP19, CT-1, NT-1.

Article Snippet: Spirochetes were pelleted at 5000 x g for 5 minutes, washed with 1x PBS, then resuspended in solution with SAA2 recombinant protein (hSAA2-His: MedChemExpress HY-P70985, Elabscience PKSH033532; mSAA2-His: antibodies online ABIN7088660) at 1μg/mL, 10μg/mL or 40μg/mL for 1h at room temperature.

Techniques: Flow Cytometry, Binding Assay, Cell Culture, Recombinant, Staining, Control, Positive Control

Journal: bioRxiv

Article Title: Borrelia Burgdorferi binds Serum Amyloid A and Modulates Subcutaneous Adipose Tissue Immune Signaling

doi: 10.64898/2026.01.29.702514

Figure Lengend Snippet: (A) Workflow diagram of labeled spirochetes added to stained cells to be measured by flowcytometry. Spirochetes were allowed to bind SAA2 previously described and labeled with CFSE. Separately, differentiated THP-1 macrophage-like cells were labeled with membrane stain DiD. Labeled spirochetes were added to stained cells and harvested at 0.5-3.0h post incubation at 37°C. (B) Flow cytometry controls of CFSE-stained Bb N40 spirochetes (green) and DiD-labeled cells (red) showing detection capability of both positive- and negative-stained populations. (C) Contour plots of THP-1 cells and spirochetes incubated with either hSAA2, 5% normal human serum (NHS), and hPGLYRP1 (10µg) comparing levels of double positive populations over time (0.5, 1.0, 2.0, 3.0h in co-culture). Contour plots show percentages of cells in each quadrant in which triplicate plots overlayed. Each replicate value from quadrant 2 (top right) used for quantification .

Article Snippet: Spirochetes were pelleted at 5000 x g for 5 minutes, washed with 1x PBS, then resuspended in solution with SAA2 recombinant protein (hSAA2-His: MedChemExpress HY-P70985, Elabscience PKSH033532; mSAA2-His: antibodies online ABIN7088660) at 1μg/mL, 10μg/mL or 40μg/mL for 1h at room temperature.

Techniques: Labeling, Staining, Membrane, Incubation, Flow Cytometry, Co-Culture Assay

Journal: Frontiers in Pharmacology

Article Title: Targeting SAA expression via siRNA mitigates preterm birth induced by maternal inflammation

doi: 10.3389/fphar.2026.1749966

Figure Lengend Snippet: SAA2 expression pattern in the mouse placenta. From embryonic (E) day 14–17, CD-1 dams received IL-1β (0.5 µg) by intraperitoneal injection daily. At E18, placentas were harvested. (A) Representative images of SAA2 expression in the PBS and IL-1β groups ( n = 3, 5 images per mouse examined). The right panels show high-magnification views of the areas outlined by white boxes in the corresponding left panels. Scale bar in the left panel, 1mm; in the right panel, 50 μm. (B) Fluorescent immune staining of SAA2 (red) and vimentin (green), an endothelial cell marker, or cytokeratin (green), a panel trophoblast marker, or F4/80 (green), a macrophage marker, in placentas. DAPI (blue) was used to label nuclei. Scale bar in left panel, 50 μm; in right panel, 10 μm.

Article Snippet: Cells were cultured with the addition of mouse SAA2 protein (CUSABIO Technology, Houston, TX) at 100–1,000 ng/mL or LPS (1 μg/mL) based on published in vitro studies ( ; ; ) and pilot experiments showing macrophage activation within this range.

Techniques: Expressing, Injection, Staining, Marker

Journal: Frontiers in Pharmacology

Article Title: Targeting SAA expression via siRNA mitigates preterm birth induced by maternal inflammation

doi: 10.3389/fphar.2026.1749966

Figure Lengend Snippet: Maternal administration of si Saa2 reduces placental SAA2 expression and alleviates abnormal placental histology and fetal brain cortical changes following sub-chronic maternal inflammation. (A) A schematic diagram illustrating the study design for the mouse model of acute intrauterine injection using LPS. (B) A schematic diagram illustrating the study strategy for the mouse model of sub-chronic maternal inflammation using IL-1β intraperitoneal injection. SiRNA was infused using intravenous injections. (C) Placental concentrations of IL-1 β were measured by enzyme linked immunosorbent assay (ELISA). ( n = 4 per group). (D) Representative Western blotting of Saa2 expression in the placenta and statistical analysis normalized to the levels of β-actin as a loading control. PBS+PBS, n = 8; IL-1 β +PBS, n = 19; IL-1 β +si Saa2 , n = 9; PBS+si Saa2 , n = 3. (E) Representative fluorescence immunostaining for Saa2 (red) and DAPI (blue, nucleic staining) in the labyrinth of placentas. n = 3, 5 images per mouse examined. Scale bars, 50 μm. (F) Real-time quantitative polymerase chain reaction (RT‒qPCR) was performed to evaluate the effect of siRNA treatment, n = 6 for each group (G) Hematoxylin and eosin (H&E) staining was performed to compare placental thicknesses at ×5 magnification. The solid arrows crossing the central cut surface of the placentas indicate the location of measurements: fetal segments were identified as a compilation of the junctional zone and labyrinth. Scale bars, 200 μm (H) Statistical analysis shows the results of H&E staining measuring fetal placental length at the thickest location. PBS+PBS, n = 3; IL-1 β +PBS, n = 4; IL-1 β +si Saa2 , n = 3; PBS+si Saa2 , n = 3. (I) Nissl staining was performed to measure cortical thickness (upper red arrows) and ventricle area (lower red panels) in the fetal brain. Scale bars, 200 μm. (J,K) Nissl staining measuring cortical thickness and ventricle area. Quantitative data, with the median indicated by the solid line for each group, represents the average of these measurements from five random brain sections for each litter. PBS+PBS, n = 3; IL-1 β +PBS, n = 6; IL-1 β +si Saa2 , n = 4; PBS+si Saa2 , n = 3 (L) The fetal viability per litter. (M) Preterm birth rates. PBS+PBS, n = 18; IL-1 β +PBS, n = 34; IL-1 β +si Saa2 , n = 30; PBS+si Saa2 , n = 10. (N) Representative images of the placenta and its corresponding fetus between groups. (O,P) Placenta (O) and fetal weights (P) . PBS+PBS, n = 10; IL-1 β +PBS, n = 16; IL-1 β +si Saa2 , n = 8; PBS+si Saa2 , n = 8. IUI: intrauterine injection; IV: intravenous; IP: intraperitoneal. Values are expressed as the mean ± SEM, One-way ANOVA with Bonferroni post hoc tests for multiple comparisons of normally distributed data and Kruskal‒Wallis with Dunn’s multiple comparisons tests for nonparametric data (C,D,F,H,J,K,O,P) . Chi-square test (L,M) , * p < 0.05, ** p < 0.01, *** p < 0.001.

Article Snippet: Cells were cultured with the addition of mouse SAA2 protein (CUSABIO Technology, Houston, TX) at 100–1,000 ng/mL or LPS (1 μg/mL) based on published in vitro studies ( ; ; ) and pilot experiments showing macrophage activation within this range.

Techniques: Expressing, Injection, Enzyme-linked Immunosorbent Assay, Western Blot, Control, Fluorescence, Immunostaining, Staining, Real-time Polymerase Chain Reaction

Journal: Frontiers in Pharmacology

Article Title: Targeting SAA expression via siRNA mitigates preterm birth induced by maternal inflammation

doi: 10.3389/fphar.2026.1749966

Figure Lengend Snippet: SAA2 induces inflammation in macrophage cells. (A) A schematic diagram illustrating our workflow involving recombinant mouse SAA2 (100 ng/mL, 500 ng/mL or 1 ug/mL) or PBS treatment of RAW264.7 macrophages for the indicated time periods (hpi = hours post-infection). (B,C) Cell phagocytosis and cytotoxicity as evaluated by flow cytometry and lactate dehydrogenase (LDH) assay, respectively. (D–G) Immune status as determined by flow cytometry (D,E) and their quantification (F,G) . (H) Concentrations of the indicated cytokines in the culture media and the time period at which they were measured by ELISA. Values are expressed as the mean ± SEM, n = 3 independent replicates performed at different time. One-way ANOVA One-way ANOVA with Bonferroni post hoc tests for multiple comparisons of normally distributed data, or Student’s t-test where appropriate. * p < 0.05, ** p < 0.01, *** p < 0.001.

Article Snippet: Cells were cultured with the addition of mouse SAA2 protein (CUSABIO Technology, Houston, TX) at 100–1,000 ng/mL or LPS (1 μg/mL) based on published in vitro studies ( ; ; ) and pilot experiments showing macrophage activation within this range.

Techniques: Recombinant, Infection, Flow Cytometry, Lactate Dehydrogenase Assay, Enzyme-linked Immunosorbent Assay

Journal: Frontiers in Pharmacology

Article Title: Targeting SAA expression via siRNA mitigates preterm birth induced by maternal inflammation

doi: 10.3389/fphar.2026.1749966

Figure Lengend Snippet: The P2X7 receptor is required for preterm birth induced by sub-chronic maternal inflammation. (A) A schematic diagram illustrating the study design. At E14-17, wild-type C57BJL (WT) and P2x7r knockout (P2X7R KO) mice underwent intraperitoneal injection (IP) with mouse recombinant IL-1 β or PBS for four consecutive days. Placenta was harvested from dams at embryonic (E) day 18. The Agarose gel at the bottom panel demonstrates multiplex PCR-based genotyping of genomic DNA samples for the detection of P2x7r (+/+) and P2x7r (−/−) genotypes. (B) At E18, fetal viability was determined as the percentage of fetuses that were viable. WT groups: PBS, n = 40 from 5 dam; IL-1 β , n = 78 from 11 dam; P2x7r −/− groups: PBS, n = 43 from 6 dam; IL-1 β , n = 43 from 7 dam. (C,D) Gel images of SAA2 expression in the placenta and statistical analysis normalized to the levels of actin as a loading control. WT groups: PBS, n = 5; IL-1 β , n = 7; P2X7R −/− groups: PBS, n = 4; IL-1 β , n = 6. One sample from the control P2X7R −/− group was excluded from analysis because the band was not fully resolved, as indicated by the vertical arrow. (E) Placental IL-1β expression following maternal inflammation as determined by ELISA. WT groups: PBS, n = 4; IL-1 β , n = 3; P2x7r −/− groups: PBS, n = 4; IL-1 β , n = 3. (F) Immunoprecipitation followed by Western blot analysis of RAW264.7 cells exposed to inflammatory conditions. IP: immunoprecipitation. Values are expressed as the mean ± SEM, Chi-square test (B) and Student’s t-test (D,E) , * p < 0.05, ** p < 0.01, *** p < 0.001.

Article Snippet: Cells were cultured with the addition of mouse SAA2 protein (CUSABIO Technology, Houston, TX) at 100–1,000 ng/mL or LPS (1 μg/mL) based on published in vitro studies ( ; ; ) and pilot experiments showing macrophage activation within this range.

Techniques: Knock-Out, Injection, Recombinant, Agarose Gel Electrophoresis, Multiplex Assay, Expressing, Control, Enzyme-linked Immunosorbent Assay, Immunoprecipitation, Western Blot

Journal: Frontiers in Pharmacology

Article Title: Targeting SAA expression via siRNA mitigates preterm birth induced by maternal inflammation

doi: 10.3389/fphar.2026.1749966

Figure Lengend Snippet: Expression patterns of SAA1 and SAA2 in the human term placenta. (A) Representative images of SAA1 and SAA2 expression in the stem villi. (B) Representative images of SAA1and SAA2 expression in the terminal villi. (C,F) Representative images of SAA1 and macrophage marker, IBA-1expression in the stem villi. (D,G) Representative images of SAA1 and endothelial marker, vimentin expression in the terminal villi. (E,H) Representative images of SAA1 and trophoblast marker, cytokeratin expression in the terminal villi. n = 5 placentas, 6 images per placenta examined, Scale bars: 10 μm for insect images; 50 μm for all other images.

Article Snippet: Cells were cultured with the addition of mouse SAA2 protein (CUSABIO Technology, Houston, TX) at 100–1,000 ng/mL or LPS (1 μg/mL) based on published in vitro studies ( ; ; ) and pilot experiments showing macrophage activation within this range.

Techniques: Expressing, Marker

Journal: NPJ Breast Cancer

Article Title: Stromal fibroblastic mutant Trp53 promotes mammary tumor development via enhanced secretion of paracrine factors

doi: 10.1038/s41523-025-00876-y

Figure Lengend Snippet: a MA-plot comparing mammary glands from NP (MG NP ) and N (MG N ) mice. Red and blue dots indicate significantly upregulated and downregulated genes, respectively (adjusted p-value < 0.05); gray dots represent non-significant changes. b Box plots show eight upregulated and seven downregulated secretory genes with adjusted p-values < 0.05. Gene expression levels in MG NP are shown in red, and those in MG N are shown in cyan. c MTT assay results showing the effects of secretory peptides on HER2/neu+ mammary tumor cell proliferation. Cells were treated with either vehicle control, SAA1, SAA2, or THBS4 peptides, and cell viability was assessed at 1, 2, or 3 days post-treatment. All comparisons to the vehicle control yielded p < 0.05, except for the optical density measured 3 days after SAA2 treatment. d Representative images from Boyden chamber assays showing the migration of HER2/neu+ mammary tumor cells in response to secretory peptides, SAA1, SAA2, or THBS4. Ctrl, vehicle control. e Transcriptional expression of SAA1 and SAA2 in breast cancer samples from the TCGA and METABRIC databases, stratified by TP53 status (WT, wild-type vs. Mut, mutant).

Article Snippet: The SAA1 (Aviva Systems Biology, OPCA03381), SAA2 (Aviva Systems Biology, OPCA00215), or THBS4 (Aviva Systems Biology, OPCA07418) peptides were added to the culture medium individually with a final concentration of 100 nM.

Techniques: Gene Expression, MTT Assay, Control, Migration, Expressing, Mutagenesis

Journal: Phytomedicine : international journal of phytotherapy and phytopharmacology

Article Title: Vaccarin ameliorates osteoarthritis by suppressing the c-Jun N-terminal kinase (JNK)-serum amyloid A2 (SAA2) pathway mediating chondrocyte senescence.

doi: 10.1016/j.phymed.2025.156697

Figure Lengend Snippet: Fig. 4. Vaccarin regulates SAA2 expression through JNK inhibition, reversing IL-1β-induced chondrocyte senescence and inflammation. (A-D) Western blot analysis showing that SP600125 treatment reversed IL-1β-induced inflammation and senescence in chondrocytes, while exogenous SAA2 protein exacerbates these effects and reduced SP600125’s inhibitory effects. (E, F) Western blot confirmed that Vaccarin reduced IL-1β-induced inflammatory and senescence markers, an effect that was counteracted by exogenous SAA2 protein. (G) β-galactosidase and ROS staining demonstrated Vaccarin’s reduction of IL-1β-induced senescence and ROS production in chondrocytes, with SAA2 reversing this effect and enhancing senescence and ROS levels. (H) Relative β-galactosidase positive cells and ROS levels were both quantified. Significance: *p < 0.05; **p < 0.01; NS, non-significance; scale bars: 200 μm (G), 400 μm (H).

Article Snippet: Recombinant mouse serum amyloid A2 protein (SAA2) (Purity > 85 %, 8478-SA) and Recombinant human IL-1β (201-LB) were purchased from R&D Systems (Minnesota, USA).

Techniques: Expressing, Inhibition, Western Blot, Staining

Journal: Phytomedicine : international journal of phytotherapy and phytopharmacology

Article Title: Vaccarin ameliorates osteoarthritis by suppressing the c-Jun N-terminal kinase (JNK)-serum amyloid A2 (SAA2) pathway mediating chondrocyte senescence.

doi: 10.1016/j.phymed.2025.156697

Figure Lengend Snippet: Fig. 8. Mechanism by which Vaccarin restores mitochondrial function in IL-1β-inhibited chondrocytes by suppressing the JNK-SAA2 signaling pathway, thereby reversing IL-1β-induced inflammation and senescence in chondrocytes.

Article Snippet: Recombinant mouse serum amyloid A2 protein (SAA2) (Purity > 85 %, 8478-SA) and Recombinant human IL-1β (201-LB) were purchased from R&D Systems (Minnesota, USA).

Techniques:

Journal: Endocrinology

Article Title: Continuous PTH in Male Mice Causes Bone Loss Because It Induces Serum Amyloid A

doi: 10.1210/en.2018-00265

Figure Lengend Snippet: NS398 blocked the RANKL induction of SAA1 and SAA2 expression in hBMMs but did not affect osteoclast-like cell numbers, and SAA1 and SAA2 inhibited PTH-stimulated osteoblastic differentiation in hBMSCs. (a–c) hBMMs were treated with M-CSF (30 ng/mL) plus vehicle (VEH) or M-CSF plus RANKL (30 ng/mL each) with/without NS398 (100 nM). (a) SAA1 and SAA2 protein measurement in the culture medium of hBMMs measured by ELISA. (b) SAA1 and SAA2 mRNA at day 3. (c) TRAP-stained microscopic images at ×100 original magnification (scale bars, 200 µm) and TRAP+ MNC counts per well. (d) ALPL (alkaline phosphatase) and BGLAP (osteocalcin) mRNA expression in hBMSCs at day 21 treated with VEH or PTH in presence of OPG (100 ng/mL) to prevent osteoclastogenesis with/without rhSAA1 (10 µg/mL) or rhSAA2 (10 to 50 ng/mL). Data are means ± SEM for n = 3 independent samples. For (a), **P < 0.01, significantly different from VEH treated at same time point, determined by two-tailed unpaired t test. For (c), **P < 0.01, significantly different from day 4, determined by one-way ANOVA, post hoc Bonferroni pairwise multiple comparisons. For (b) and (d), *P < 0.05, **P < 0.01, determined by two-way ANOVA, post hoc Bonferroni pairwise multiple comparisons.

Article Snippet: Recombinant murine (rm) macrophage colony-stimulating factor (rmM-CSF, 416-ML), recombinant human (rh)M-CSF (216-MC), rmRANKL (462-TEC), rhRANKL (390-TN), rmOPG/Fc-chimera (459-MO), and rhOPG (185-OS) were purchased from R&D Systems (Minneapolis, MN). rhSAA1 (30053) was from PeproTech (Rocky Hill, NJ). rhSAA2 (TP304977) was from Origene (Rockville, MD).

Techniques: Expressing, Enzyme-linked Immunosorbent Assay, Staining, Two Tailed Test